Questions from class discussion:
Dear Students,
This post is being created as a platform for questions which arise during class discussion. You can post your answers and relevant information here.
Just type the question, followed by your answer/ comments, and other can join.
Load cell:
ReplyDeleteIt is a method of measuring changes in weigth in a fermentor using deformation of crystal as indicator of load. Load cell is mounted in such a way that only fermentor and its content are measured. Deformation of load cell provides output that can be transduced into an electrical signal. Control is normally by setting maximum/minimum weigth such that feed pump operates whenever the value is less than maximum. At maximum value, second pump operates to remove culture until minimum weigth is reached.
This method is low profile construction and reduced dimensions makes it ideal for use.
High strength aluminium alloy is used as spring elements and the sensors are fully protected with silicon coating.
Accuracy is 99.95% and repetability is 99.97%
Reference: Fermentation microbiology & biotechnology 2edition
https://www.bioreactorsciences.com/loadcell.html
This comment has been removed by the author.
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteMild steel definition:
ReplyDeleteIt is an iron carbon alloy containing less than 0.25% carbon which makes it more ductile and less hard thus rendering it unsuitable for structural work
Property of mild steel:
DeleteMild steel is suitable for mechanical engineering and general purpose fabrication. Its strength makes it a terrific choice of material for the construction of cages, frames, fencing and in other applications where it will not be subjected to high stress.
Bright mild steel, which is cold finished for an enhanced aesthetic appearance, has tighter sectional tolerances and increased straightness. It has a marked increase in physical strength over standard mild steel which makes it a better
What does numbering in steel indicates:-
ReplyDeleteEngineering handbooks point out that the classification of steels comes under the authority of the Society of Automotive Engineers (S.A.E.) or American Iron and Steel Institute (A.I.S.I.) for its coding system. The system of coding was originated in the early 1940’s and it was done with the expressed intention of giving engineers, designers, draftsmen, or heat treaters specific information on the types and grades of steel available. The system is very effective for steels using the A.I.S.I. and S.A.E. standards.
The S.A.E. or A.I.S.I. classifications contains 4 to 5 numeric characters with additional alpha characters added to designate special characteristics of the steel. Here is the coding system definition. (Examples: 1018, 12L14, 4140, 41L40 )
The very first number depicts a general category grouping of steels. That is:
1indicates carbon steel: 1XXXX
4indicates molybdenum steel: 4XXXX
5indicates chromium steel: 5XXXX
6indicates chrome vanadium steel: 6XXXX
8indicates nickel chromium molybdenum, steel: 8XXXX
9indicates silicon manganese steel: 6XXXX
The second number gives indication if there are elements present that effect attributes of the steel. The last two digits (three digits for a few grades) represents the actual nominal percentage of carbon content present.
Source:-
https://www.epsovens.com/blog-news/understanding-the-carbon-steel-grade-system/
stainless steel:
ReplyDeletea steel alloy with a minimum of 11.5% chromium content.it does mot stain,corrode or rust easily. it is a high corrosion resistance.
Stainless steel:
ReplyDelete🔹It is defined as a steel alloy with a minimum of 11.5 wt% chromium content.
🔹Stainless steel does not stain, corrode or rust as easily as ordinary steel (it “stains less”).
🔹Stainless steel differs from mild steel by amount of chromium present.Stainless steels have sufficient amount of chromium present so that a passive film of chromium oxide forms which prevents further corrosion.
Mild steels:
🔹Carbon steel is sometimes referred to as ‘mild steel’ or ‘plain carbon steel’.
🔹Typically carbon steels are stiff and strong.
🔹More ductile, machinable and weldable than high carbon and other steels.
🔹Relatively affordable compared to other steels.
A load cell is a transducer that is used to create an electrical signal whose magnitude is directly proportional to the force being measured. The various load cell types include hydraulic, pneumatic, and strain gauge.
ReplyDeleteLoad cells work by converting a weight reading into a signal that is then read by a computer located somewhere else, called the terminal. Load cell technology is easily integrated into many kinds of instruments, machines, vehicles and other devices.
Stainless steel is more suitable for fermentation process because it is easier to clean, offer excellent weldability, corrosion resistance, oxidation resistance,strength at high temperatures, can be incorporated into austenitic stainless steels by adding certain alloys like chromium, nickel, molybdenum, nitrogen, titanium, and columbium.
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteMild steel:
ReplyDeleteIt is also know as carbon steel.
It has carbon content of 2%.
It is more stiff n strong.
Corrosion resistance is poor.
Stainless steel:
It is defined as a steel alloy with a minimum of 11.5 wt% chromium content.
It doesn't get corrode easily when compared with other steel.
Stainless steel differs from mild steel by amount of chromium present.Stainless steels have sufficient amount of chromium present so that a passive film of chromium oxide forms which prevents further corrosion.
Source of above post:peralitesteel.com
Deletewhat is DEL factor ?
ReplyDelete- Deindoerfer and Humphery used the term ln (Nt / N0) as a
design criterion for the sterilization which has been
called as DEL Factor or NABLA factor.
- Del factor is a measure of fractional reduction of viable
organism count produced by a certain heat and time regime.
- ∇ = ln (Nt / N0)
∇ = A. t. e –E/RT
Since from above it is clear that del factor is used for study of sterilisation criteria.It is evident from the equation that the temperature and time are inversely proportional and same degree of sterilisation can be acheived by varying time and temperature.
DeleteThis comment has been removed by the author.
ReplyDeleteRole of carbon in steel:
ReplyDeleteCarbon is one of the important thing used in steel preparation, its increased content increases its hardness,strength and improves hardenability.
Mainly carbon content ranges till maximum of 2%,depending upon its carbon content it is further classified into:
1.low carbon steel(<.30%)
2.medium carbon steel(.30%-.45%)
3.high carbon steel(.45%-.75%)
4.ultrahigh carbon steel(.75%-1.65%).
Source:www.fabricator.com
What is stoichiometry? what is a stoichiometric process?
ReplyDeleteAns: Stoichiometry is a section of chemistry that involves using relationships between reactant or products in a chemical reaction to determine desired quantitative data.
Stoichiometric process is the process in which the amount of product yielded by a reaction can be known.
This comment has been removed by the author.
ReplyDeleteLoad cell and material it is made up of:
ReplyDeleteA load cell is a transducer that is used to create an electrical signal whose magnitude is directly proportional to the force being measured. There are various types of load cell, which include:hydraullic load cell,pneumatic load cell, strain guage laod cell.
The most common type of load cell used is strain
Guage load cell.
Mainly load cells are made up of different types of steels ie, satinless steel, aluminum steel, alloy steel-which can be caoted or plated with nickel, tool steel. They posses various properties such as high strength, low weight, high mallability, corrode resistance, good thermal n electrical conductivity etc, due to this properties it makes it suitable for load cell.
This comment has been removed by the author.
ReplyDeleteLoad Cell
ReplyDeleteLoad cell is a type of transducer which performs the functionality of converting force into an electric output which can be measured. It is basically a device that measures strain and then converts force into electric energy which serves as measurement .
Functionality
pneumatic, strain gauge and hydraulic load
What is load cell?
ReplyDeleteA load cell is a sensor or a transducer that converts a load or force acting on it into an electronic signal. This electronic signal can be a voltage change, current change or frequency change depending on the type of load cell and circuitry used. There are many different kinds of load cells out of which most common type is Guage load cell .
Mild steel vs. stainless steel:-
ReplyDeleteStainless Steel contains a minimum of 10.5% chromium content by mass.
Mild Steel is also known as carbon steel it contains between 0.05–0.25% carbon.
Stainless steel is a chromium based steel alloy
mild steel is a carbon based steel alloy.
Stainless Steel is known for its high corrosion resistance, which means that it does not stain, rust, or tarnish,
a feature that mild steel does not have.
Stainless Steel is also very resilient to impact, due to its high level of hardness,
Mild steel does not have the same level of hardness, its surface hardness can be increased through carburizing.
Stainless Steel may or may not be magnetic.
Mild Steel typically is magnetic which makes it great for use in certain electrical or mechanical appliances.
stainless steel usually has a more clean and streamline look, something that mild steel lacks
A load cell is a transducer which converts force into a measurable electrical output. Although there are many varieties of load cells, strain gage based load cells are the most commonly used type.
ReplyDeleteHowever these load cells are made of various metallic parts, these metallic parts are made from the following materials:
Stainless steel.
Aluminium.
Alloy steel which can be coated or plated with nickel.
Tool steel.
Each of these materials have various properties that makes them suitable to be used for load cells, such properties are high strength, low weight, high malleability, corrosion resistance, good thermal and electrical conductivity, high cryogenic toughness, attractive appearance, high work hardening rate, easy machining etc.
This comment has been removed by the author.
ReplyDeleteIn a nutshell, main differences between Carbon Steel & Stainless Steel
ReplyDeleteThere is an in built chromium oxide layer in stainless steel, which is not present in carbon steel.
Carbon steel can corrode whereas stainless steel is protected from corrosion
Stainless steel is preferred for many consumer products and can be used decoratively in construction, while carbon steel is often preferred in manufacturing, production and in projects where the steel is mostly hidden from view.
Stainless Steel has lower thermal conductivity than Carbon steel
Mild steel is also known as Carbon steel.
steel numbering system:-
ReplyDeletetwo major numbering systems used by the steel industry, the first developed by the American Iron & Steel Institute (AISI),the second by the Society of Automotive Engineers (SAE).
Both of these systems are based on four digit code numbers when identifying the base carbon and alloy steels.
If the first digit is a one (1) in this designation it indicates a carbon steel. They are also subdivided into four categories due to particular underlying properties among them. See below:
Plain Carbon Steel is encompassed within the 10xx series (containing 1.00% Mn maximum)
Re-Sulfurized Carbon steel is encompassed within the 11xx series
Re -Sulfurized and Re-Phosphorized Carbon Steel is encompassed within the 12xx series
Non-Re-Sulfurized High-Manganese (up-to 1.65%) carbon steel is encompassed within the 15xx series.
The first digit on all other alloy steels (under the SAE-AISI system), are then classified as follows:
2 = Nickel steels.
3 = Nickel-chromium steels.
4 = Molybdenum steels.
5 = Chromium steels.
6 = Chromium-vanadium steels.
7 = Tungsten-chromium steels.
8 = Nickel-chromium-molybdenum steels
9 = Silicon-manganese steels and various other SAE grades
The second digit of the series (sometimes but not always) indicates the concentration of the major element in percentiles (1 equals 1%).
The last two digits of the series indicate the carbon concentration to 0.01%.
For example: SAE 5130 is a chromium alloy steel containing about 1% of chromium and approximately 0.30% of carbon.
Overflow metabolism
ReplyDeleteOverflow metabolism refers to the seemingly wasteful strategy in which cells incompletely oxidize their growth substrate (for e.g. glucose) instead of using the more energetically-efficient respiratory pathway, even in the presence of oxygen. As a result of employing this metabolic strategy, cells excrete metabolites like lactate, acetate and ethanol. Incomplete oxidation of growth substrates yields less energy than complete oxidation through respiration. It's also known as Warburg effect in context of cancer.
This comment has been removed by the author.
ReplyDeleteThe apparatus used as load cell is a strain gauge rosette which is a term for an arrangement of two or more strain gauges that are positioned closely to measure strains along different directions of the component under evaluation. Single strain gauges can only measure strain effectively in one direction, so the use of multiple strain gauges enables more measurements to be taken, providing a more precise evaluation of strain on the surface being measured.
ReplyDeleteLoad cell consists of Zinc-plated, 304 or 316 stainless steel mounting hardware
ReplyDeleteLink: https://www.mt.com/in/en/home/products/Industrial_Weighing_Solutions/AutomPrecision/load-cell-and-weigh-module/compression/SWB605-powermount.html
Laboratory scale fermentor- for small scale production, glass or stainless steel can be used for construction.
ReplyDeletePilot scale and large scale- for pilot scale and large scale fermentors, mild steel coated with glass or e epoxy materials are used. AISI grade 316 which contains 18% chromium, 10% nickel and 2-2.5% molybdenum are commonly used.
for citric acid production where pH is 1-2, stainless steel of AISI grade 304 is commonly used.
What is piezometry?
ReplyDeletePiezometry is a method to measure very high pressure.
Piezometer is an instrument that measure pore-water pressure and ground water levels.
http://www.slopeindicator.com/instruments/piezo-intro.php
This comment has been removed by the author.
ReplyDeleteNOISE:
ReplyDeleterandom fluctuations in the signal. usually quantified using the standard deviation of multiple measurements of the blank.
Noise refers to information or activity that confuses or misrepresents genuine underlying trends.
Difference between noise and signal:
ReplyDeleteSignal carries information about the analyte, while the noise is made up of extraneous information that is unwanted because it degrades accuracy and precision of the measurement.
types of noise:
1. Chemical- arises from uncontrollable variables such as fluctuations in temperature or pressure, changes in relative humidity, reaction with oxygen, etc.
2.Instrumental- associated with components in the instrument(e.g, source, input transducer, the output transducer, and all signal processing elements.)
Noise free data can never be realized in practice.Signal processing aims at extracting information from the raw signal. The difficulty in reaching this goal depends both on the characteristics of the noise-free signal and the noise. The signal-to-noise-ratio is the ratio of the strength of the signal and the strength of the noise. The higher the ratio the easier it is to extract information and the more reliable are the results.
Reference: https://www2.chemistry.msu.edu/courses/cem434 chapter5: noise pdf
Fundamentals of statistics: http://www.statistics4u.com/fundstst_eng/cc_signal_noise.html
How do we measure the pH of solid materials?
ReplyDeleteAs we know that pH is the measurement of hydrogen ion present in the solution so we can dissolve the solid into the water and then we can measure the pH of the solid.
NOISE:
ReplyDeleteUnwanted disturbance in an electrical signal.
Noise is made up of foreign information that is abdicable because the accuracy and precision of an analysis.
SOURCES OF NOISE:
Air currents , Electric power fluctuations , Stray radiation from nearby electrical equipment,Static electricity,Turbulence in the flow of gas/liquid, Random thermal motion of molecule, Background radiation from natural radioactive elements.
REFERENCE:
http://www.sc.eso.org/~ohainaut/ccd/sn.html
https://terpconnect.umd.edu/~toh/spectrum/SignalsAndNoise.html
This comment has been removed by the author.
ReplyDeleteBIOSENSOR
ReplyDeleteA biosensor is a analytical device which integrates the biological elements with the physiochemical transducer to produce an electronic signal is proportional to a single analyte and which is fetched into a detector.
Reference: www.edgefx.in/biosensors-types-its-working-and-applications
The instrument used for measuring pH of skin is a pH-m V meter, linked to combination surface measuring glass electrode. The system is calibrated by testing repeatedly for accuracy using ready buffer solutions of
ReplyDeletepH 4.00,4.66, 5.00, 6.00, 6.88, and 7 .00. The accuracy over the range of interest was found to be at least 0.02 pH units. It is done three times to compensate for possible fluctuations that may exist even between closely adjacent areas. For this, the electrode should be rinsed in bidistilled water and shaken to remove most of the water; slightly moist, it is gently pressed to the middle of the forehead, above the
root of the nose, and to the forearm close to the flexor crease. Readings are taken when the display had steadied out, and not later than after one minute.
Determination of kLa values- different methods
ReplyDelete1.sulphite oxidation method
2.Gassing out technique- static and dynamic
3.Oxygen balance technique.
which technique is more efficient?
The oxygen-balance technique appears to be the simplest method for the assessment of kLa and has the advantage of measuring aeration efficiency during a fermentation. The sulphite oxidation and static gassing-out techniques have the disadvantage of being carried out using either a salt solution or an uninoculated, sterile fermentation medium.
sulphite oxidation method is time consuming method.
static gassing out technique is used on small scale only.
In dynamic gassing out technique major limitation in the operation of the technique is the range over which the increase in dissolved oxygen concentration is measured.
This comment has been removed by the author.
ReplyDeletekla is determined by 5 different methods
ReplyDelete1) chemical method
2) dynamic differential gassing out method
3) dynamic integral gassing out method
4) oxygen balance method
5)enzymic method
Cheapest and widely used method is dynamic differential gassing out method.
This comment has been removed by the author.
ReplyDeleteQues: Non-Newtonian fluids and its classification:
ReplyDeleteThe Non Newtonian nature is due to the composition of a fermentation broth which is not uniform and complex. The fermentation broth often show complex interactions of solid, liquid and gas phases. The rheology of the fermentation broth is always changing as a function of time and with the progress of the fermentation.The main impact of Non Newtonian rheology is that it affect mixings and mass transfers of heat and oxygen and prevent efficient homogenous composition to occur. Rheology is the study of fluid deformation and flow under pressure and the relationship between stress and strain. Each rheological type will give different mixing profile.
This has led to the classification of various classes of Non Newtonian fluids such as
1-viscoplastic fluid,
2-bingham fluid,
3-pseudoplastic fluid,
4-dilatant fluid
Non Newtonian rheology curves can be made up of various types. Most of these rhelogical curves are graphs where the x- axis is shear stress and the y- axis is shear rate.
Generally all Non Newtonian fluids show some similarity in relationship with Newtonian fluid reflecting the effect of shear stress on shear rate. There is roughly a direct linear relationship (with variations) between shear stress and shear rate.
Differences only that Newtonian fluid adhere strictly and very linear and start at point zero of the axis.
1 Viscoplastic and Bingham starts only after certain level of shear stress. This means that the fluid will NOT respond immediately to applied stress and will only react after reaching the critical power point
2 Pseudoplastic and dilatants start at zero point but are curved in their shape. This mean that the fluid will respond immediately to the power or energy input. This is similar to Non Newtonian. However their response will be different in that it is not a linear relationship between stress and shear rate
3 Viscoplastic, pseudoplastic and dilatants are curved in their shapes This means that these fluids react in their yield behavior under stress differently. These rheological graphs will tell us how to respond efficiently with the type of broth being fermented.By understanding the various rheological changes that occur in the fermentation broth we can:
1 Try to achieve uniform homogenization and optimum mass transfer
2 Try to optimize energy usage in mixing of the fermentation broth
In carrying out the fermentation, we are using the impeller to mix the broth. Energy is transferred and dissipated to the broth by the impeller system. The impeller is in simplicity the shear stress being enforced upon the broth.
The effect of the impeller or mixing on the broth will result in the flow or turbulence of the broth. The broth will respond by exhibiting stress yield properties such as thinning out of the broth to improve mass transfer processes.
So if we know the rheology of the fermentation broth it will help us to adapt to obtain very efficient fermentation by adjusting our mixing regimes. This is especially so when the rheology changes with time and conditions.
Reference: http://fermentationtechnology.blogspot.in/2010/01/rheology-part-four-applying-rheology-to.html?m=1
Description of two biosensors-
ReplyDelete1. Glucose detection-
Micro-enzyme electrode acts as a detector in FIA system. The sensor is based on a solid-state micro sensor on which polyvinyl pyridine matrix, doped with mediator molecules is placed. co-immobilization of transistor gate glucose oxidase and gluconolactonase by glutraldehyde forms a glucose biological field effect transistor(FET). The gluconolactonase increases the hydrolysis rate of
the gluconolactone produced by the action of glucose
oxidase on glucose.The FET system enables correction of pH variation and buffer capacity during fermentation.
2. Determination of antibiotic concentration-
sensor determining penicillin V concentration
A penicillin V electrode is been obtained by the
immobilization of penicillinase at the sensitive tip of
a glass pH electrode by crossllnking with a fine film
of glutaraldehyde. The assembly is incorporated
into a FIA system. During a penicillin fermentation
the antibiotic concentration varies widely.
The composition of the complex medium, which contains
many interfering components, varies also and pH
changes can be expected when fermenter pH control
is not well tuned. The magnetically stirred flow
cell is the most efficient device for sample dilution
and reduction of interference problems.
Two biosensors :-
ReplyDelete1. Alcohol detection- A colorimetric biosensor was proposed
by Kuswandi. The sensor was constructed by polyaniline
film immobilized alcohol oxidase. When ethanol is in
presence, a color change from green to blue can be
observed due to the oxidation of polyaniline by the
enzyme reaction product hydrogen peroxide. Through the
computer processing software, the method can determine
alcohol quantitatively range between 0.01 to 0.8%.
Gotoh devised an amperometric alcohol sensor based on
co-immobilized alcohol dehydrogenase and coenzyme NAD+,
the enzyme electrode shown linear response to solution
contains ethanol between 0.05 and 10 v/v%. As a
reagentless enzyme sensor, it can stand at least weeks
of continual detections without addition of the
coenzyme.
2. Aminoacid detection - Biosensing tactics for amino acids
are mainly realized by using enzyme biosensors.
Stasyuk used recombinant yeast cells as the arginine
activity source to establish an amperometric biosensor
along with immobilized urease. The cell-enzyme coupled
sensor reportedly exhibited a linear range cross 3
orders of a magnitude up to 0.6 mM and can give the
result within no more than 1 min. Another strategy is by
coupling arginase (EC 3.5.3.1) and urease (EC 3.5.1.5).
An arginine biosensor was constructed on ion-selective
field effect transistors (ISFETs) surface via co-
immobilizing arginase and urease. When working, arginine
catalyzes the conversion of arginine into ornithine with
release of urea, which, in turn, is degraded by urease
to produce ammonium ions. Production of ammonium is
accompanied by the subtle change of pH and thus can be
detected by the transmitter.
Biosensors that are used in fermentation industry
ReplyDeleteDNA biosensors were devised on the property that single strand nucleic acid molecules recognize and binds to its complementary strand in the sample . Hence it is typically based on nucleic acid recognition . It can also be used in food analysis.
Magnetic Biosensors : Here the cells, proteins , Ab are labeled with superparamagnetic microbeads. Now this labeled species are immobilized on the chips and are detected by magnetic sensors that is integrated into a chip .
Biosensors used in fermentation industries: Based on types of microorganims used and the product of interest.
ReplyDeletehttps://www.sciencedirect.com/science/article/pii/S095656631000607X
How against diffusion gradient the extracellular product gets accumulated?
ReplyDeleteAns. The volume of intracellular membrane decreases as the culture condition changes.
And there by at different growth stages the volume of intracellular membrane changes this can be one of the reason that after certain growth where product is formed and excreted outside the intracellular membrane's volume decreases and so that backflow is prevented because not many molecules og tge same can be accommodated.
Reference for the above answer:
ReplyDeletePaper published in Journal of bacteriology
Link: https://www.google.co.in/url?sa=t&source=web&rct=j&url=https://pdfs.semanticscholar.org/7e52/b1222714cf8834bebaa75414a97eba99905a.pdf&ved=2ahUKEwjQoYHn-qbZAhVFQY8KHUGpCc4QFjAAegQICxAB&usg=AOvVaw1mlsGpR8bpzqVc66cVS99q
The only difference between Carbon and activated carbon is the number of pores present on the carbon.
ReplyDeleteActivated carbon has more micropores as compared to carbon due to which the adsorbing capacity of activated carbon is greatly increased.
Carbon can be activated both by physical and chemical methods.
List of fermentation industry in INDIA-
ReplyDeleteBHARAT BIOTECH
SHANTA BIOTECH
JM EDWARD
BIOCON
PANACEA BIOTECH LTD
NOVOZYMES
GLAXOSMITH KLINE LTD
this link has list of fermentation industries in india with their major products products, 264 companies are been listed.
ReplyDeletehttp://biotechsupportbase.com/resources/for-all-people/biotech-companies/biotech-companies-list/
List of some fermentation industries in India :
ReplyDeletePrathista Industry pvt. Ltd - manufacturer of Organic/Eco-friendly fertilizer (OMRI listed products), Veterinary feed supplements (including protein based chelated minerals), and Poultry feed supplements, Pharmaceutical (including gluconic acid and salts, lactic acid and salts) products through fermentation technology. Asia’s largest fermentation based manufacturing unit (3,00,000 Lts fermentation capacity
International Pinaacea limited - commercialization of industrially important Bio-products such as Bio-fertilizers, Bio-pesticides produced by fermentation processes.
Harsh and Vardhan impex pvt. ltd. -
manufacturing of Organic chemicals based on fermentation grade alcohol, namely Acetaldehyde - 20000 TPA, Acetic Acid - 22000 TPA, Ethyl Acetate - 25000 TPA and AlCl3 - 5000 TPA
M/S KFIRM lifesciences pvt ltd. -
manufacturing and marketing of an exclusive range of products for
Agriculture and Industrial application such as Food, wheat milling, pulse
processing, Bakery and Biscuit, alcohol processing and
industrial waste effluent treatment.
There are many more industries producing wide range of products produced through fermentation.
Link: https://companylist.org/India/Keywords/fermentation/
https://www.google.co.in/url?sa=t&source=web&rct=j&url=http://biotechsupportbase.com/resources/for-all-people/biotech-companies/biotech-companies-list/&ved=2ahUKEwjTxsq5qu3ZAhULsI8KHe76A8AQFjAFegQICBAB&usg=AOvVaw1jXK8eiCw9NvmbF9Ow1OX0
1 dalton is numerically equivalent to 1g/mol.
ReplyDeleteThis comment has been removed by the author.
ReplyDelete1000 dalton = 1.66053E-21 gram
ReplyDeleteThis comment has been removed by the author.
ReplyDelete) a unit of mass used to express atomic and molecular weights that is equal to one twelfth of the mass of an atom of carbon-12. It is equivalent to 1.66 × 10–27 kg.
ReplyDeleteThe unified atomic mass unit or dalton (symbol: u, or Da) is a standard unit of mass that quantifies mass on an atomic or molecular scale (atomic mass). One unified atomic mass unit is approximately the mass of one nucleon (either a single proton or neutron) and is numerically equivalent to 1 g/mol.
ReplyDelete1 dalton= 1.660539040(20)×10−27 kg
ReplyDelete1 dalton = 1.66054x10-24 grams
ReplyDelete1 dalton = 1.66054x10-27 kilograms
The act of devouring one's own young (often seen in animals; some animals eat their young cubs/babies of the same species) is refered to as *filial cannibalism*.
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteDalton is a very small unit of mass, about the mass of a hydrogen atom. Presently taken as an alternative name for the unified atomic mass unit, that is, one-twelfth of the mass of a carbon-12 atom, about 1.660 538 86 × 10⁻²⁷ kilogram.
ReplyDeleteDalton is unit of mass, equal to 1/12 the mass of the carbon-12 atom and used to express the mass of atomic and subatomic particles. It is equivalent to 1.66 × 10–27 kg.
ReplyDeleteThe masses of atoms commonly are expressed in atomic mass unit or dalton . The dalton is defined in this way: the dalton is the twelfth part of the mass of an atom of 12C
ReplyDeleteFrom this definition comes down immediately that the mass of an atom of 12C is 12 u.
So I dalton = 1.6605402e-24 gram
Dalton is a unit of mass which is equal to one-twelfth of the mass of a carbon-12 atom, about 1.660 538 86 × 10⁻²⁷ kilogram. Symbol: Da
ReplyDeleteDalton is unified atomic mass unit.
ReplyDelete1 dalton = 1.660530000001 x 10-21 milligram
1 dalton = 1.660530000001 x 10-24 gram
1 dalton = 1.660530000001 x 10-27 kilogram
Here is the list of some of the fermentation industries in India
ReplyDeleteMaps (India); Ahmedabad; Producer and exporter of industrial enzymes like amylases using solid and submerged fermentation.
Novozymes - Enzymes and biocatalysts producer
Ppayin Products (India); Coimbatore; Manufactures papain and bromelain enzymes from papaya
Zytex (India); Mumbai; Manufactures enzymes for various industries like baking, food processing, leather, and auxillaries for fabric garment processing and feed additives.
Alltech Biotechnology; Bangalore; Animal feed solutions provider using natural yeast fermentation and enzyme technology.
Concord Biotech; Ahmedabad; Producer and exporter of enzyme- statins having state-of-the-art fermentation facilities
International Panacea; New Delhi; Work on industrially important products mainly produced by fermentation processes, like- biofertilizers, biopesticides, nutraceuticals, recombinant proteins and biomolecules
Reference: http://www.indiabiotech.in/Food-Industrial%20Biotech-Companies.htm
This comment has been removed by the author.
ReplyDeleteHere are some list of fermentation industries in India..
ReplyDeleteBiocon
Established in 1978 and based in Bengaluru, Karnataka, Biocon is an Indian biopharmaceutical enterprise. Biocon's businesses and services include small molecules, biosimilars, branded formulations, novel molecules and research services.
Serum Institute of India
Serum Institute of India is an Indian biotechnology company that manufactures immunobiological drugs and vaccines. Serum Institute of India was founded in 1966 and is headquartered in Pune, Maharashtra. The company is amongst the leaders in making the Rubella, Tetanus, Measles and Diphtheria vaccines in India.
Panacea Biotec Limited
Panacea Biotech Limited was incorporated in 1984 and is headquartered in New Delhi. It is an Indian health management and research based pharmaceutical company involved in research and marketing of natural products, vaccines and pharmaceutical formulations. Panacea is surely amongst the top biotechnology companies in India that serve the medical fields such as nephrology, orthopaedic, respiratory and diabetology through their quality products.
Dr. Reddy’s Laboratories Limited
Dr. Reddy's Laboratories Limited is also one of the leading biotech companies in India. It was established in 1984 and has its headquarters in Hyderabad, Telangana. A vast range of pharmaceutical products are manufactured by Dr. Reddy's Laboratories in India and abroad. It produces diagnostic kits, biotechnology products and pharmaceutical Ingredients.
Wockhardt
Wockhardt was founded in 1967 and is headquartered in Mumbai, Maharashtra. The premium range of products manufactured by Wockhardt belongs to pharmaceutical ingredients, pharmaceutical and biopharmaceutical formulations.
GlaxoSmithKline Pharmaceuticals Limited
One of the oldest and most experienced players in the biotechnology industry of India, GlaxoSmithKline Pharmaceuticals Limited was incorporated in 1924. Its medicines range across therapeutic areas such as respiratory diseases, anti-infectives, cardiovascular diseases, dermatology, oncology, gynaecology and diabetes. It also provides vaccines for cervical cancer, hepatitis B, hepatitis A, rota-virus, influenza, tetanus, chickenpox, pertussis and diphtheria amongst many.
Bharat Serums and Vaccines Limited
Bharat Serums and Vaccines Limited was started in 1971 and has its headquarters in Mumbai, Maharashtra. It is an Indian manufacturer of biotechnological and pharmaceutical products. The significant medical fields that are covered by a wide range of pharmaceutical products provided by Bharat Serums and Vaccines Limited are nephrology, critical care and haemetology.
Indian Immunologicals Limited
Indian Immunologicals Limited is a top Indian biotechnology company founded in 1982 by The National Dairy Development Board (NDDB). It has biotechnology laboratories and manufacturing plant in Hyderabad, Rajkot and Ooty. Indian Immunologicals Limited is renowned for manufacturing vaccines for foot-and-mouth diseases such as bacterial diseases, rabies, hepatitis, canine vaccines, measles, DPT and MMR.
Shantha Biotechnics Limited
Shantha Biotechnics Limited is an Indian biotechnology firm incorporated in 1993 and is headquartered in Hyderabad, Telangana. The company manufactures vaccines for the diseases such diphtheria, tetanus, influenza and cholera.
https://business.mapsofindia.com/india-company/top-10-biotech-companies.html
A unit of mass used to express atomic and molecular weights that is equal to one twelfth of the mass of an atom of carbon-12. Also called as unified atomic mass unit or dalton.
ReplyDeletehttps://www.convertunits.com/from/dalton/to/kg - reference for conversion of Dalton
ReplyDeletesteel no. 316 is molybdenum alloy having 16-18% Cr, 10-14% nickel, 2% Mn, 0.75% silicon, 2-3% Mo, 0.08% carbon.
ReplyDeleteHigh-nitrogen grade with increased resistance to pitting and to corrosion in crevices. Used for chemical handling accessories and food processing, chemical storage.
Steel no 316
ReplyDeleteChemical Formula
Fe, <0.03% C, 16-18.5% Cr, 10-14% Ni, 2-3% Mo, <2% Mn, <1% Si, <0.045% P, <0.03% S
Type 316 steel is an austenitic chromium-nickel stainless steel that contains between two and three percent molybdenum.
The molybdenum content increases corrosion resistance, improves resistance to pitting in chloride ion solutions and increases strength at high temperatures.
Type 316 grade stainless steel is particularly effective in acidic environments. This grade of steel is effective in protecting against corrosion caused by sulfuric, hydrochloric, acetic, formic and tartaric acids, as well as acid sulfates and alkaline chlorides.
Refrence: https://www.thebalance.com/type-316-and-316l-stainless-steel-2340262
What is the affect of manganese on citric acid production?
ReplyDeleteThe addition of as little as 2 ppb of manganese to ferrocyanide-treated beet molasses during citric acid fermentation by Aspergillus niger NRC A-1-233 caused a 10% reduction in acid yield and undesirable change in the morphology of the organism from the normal pelletlike form to the filamentous from. The adverse effect of manganese on growth and acid production was not affected by addition of the other metals.
Steel 316 is a molybdenum alloyed steel (16% chromium, 10% nickle,2% molybdenum )
ReplyDeleteit has greater resistance to corrosion to chloride( hence regarded standard marine grade stainless steel )
good welding characteristics
Tensile strength: 515 MPa
Density:8000 kg/m^3
Has higher strength at elevated temperatures(thus application above temp. 500 degree c)
source:www.azom.com
The link below provides information abot steel-316
ReplyDeletehttps://www.google.co.in/amp/s/www.azom.com/amp/article.aspx%3fArticleID=2382
Uptake of citric acid by A.niger occurs by active, pH driven, H+ symport dependant systems. The export of citrate by A.niger was facilitated in a manganese-deficient condition, whereas the uptake of citrate from the medium was facilitated in a manganese-rich medium in which the A.niger was precultivated.
ReplyDeleteThis may be a major reason why the concentration of manganese in the medium /fermenter broth should not be above a cut-off value.
This was studied by experimenting with different concentrations of 14C citrate and the subsequent export of radiolabelled citrate into the medium. The decrease in manganese ion concentration in the medium resulted in measurable citric acid export. However, the dependency of A.niger on manganese can also be partially fulfilled by other divalent metal ions such as ferrous ions and cupric ions.
It was also observed that at low concentrations of manganese (below 10^-8 molar) no citrate uptake was measurable.
Reference : sciencedirect.com
Article : https://doi.org/10.1016/S0005-2736(97)00032-1
By RAMYA J IYER
17MBT016
Mild steel (aka carbon steel) is a carbon-based steel alloy. It has 0.05-0.25% carbon. Whereas stainless steel contains a minimum of 10.5% chromium content by mass.
ReplyDeleteThe wishlist for a fermentor body materials, as discussed in lectures, is
Not prone to corrosion
Acid resistant
Not allow biofilm formation
Should not interact with microorganisms (no ionic interactions)
High strength in terms of tolerance of stress (in the form of repetitive heating/cooling/steam sterilisation etc)
Thermal resistant
Smooth surface
Stainless steel (more particularly steel 316) still can eventually rust, can get marked by fingerprints, grease but it can withstand much more abuse before showing signs of wear.
1. It has relatively higher chromium, and especially molybdenum (alloy) which gives it corrosion resistance (specifically saline or chloride-exposed environments)
2. Good oxidative resistance in intermittent service to 1600°F (870° C) and in continuous service to 925° C.
3. Strength (tensile) is 84100 psi
4. Easily cleanable
5. Can be welded easily and handled easily.
6. Polished surface appearance ; smooth surface.
7. High tolerance to acid levels
Because of these reasons, steel 316- although costlier than steel 304 -is used majorly in many areas such as industries, medicinal field for surgical instruments, and food industry.
By
17mbt016
Ramya j iyer
Grade 316 is the standard molybdenum-bearing stainless steel.
ReplyDeleteThe molybdenum gives this grade steel corrosion resistant properties, higher resistance to pitting and crevice corrosion in chloride environments.
It has excellent forming and welding characteristics.
Density: 8000kg per meter cube.
Elastic modulus: 193 GPa
316 grade stainless steel is an austenitic form of stainless steel known for its 2-3% molybdenum content. The added molybdenum makes the metal more resistant to pitting and corrosion, as well as improving resistance when exposed to elevated temperatures.
ReplyDeleteeffective when used in acidic environments. With this metal, corrosion that is caused by acetic, hydrochloric and other forms of acids can be prevented.
Chemical Formula
Fe, <0.03% C, 16-18.5% Cr, 10-14% Ni, 2-3% Mo, <2% Mn, <1% Si, <0.045% P, <0.03% S
Role Of Mn on production of citric acid??
ReplyDelete. Manganese deficiency affects the anabolism of A. niger, causing a high intracellular ammonium concentration. A decrease in the accumulation of citric acid with iron has been observed, as well as changes in mycelial growth. Which means by addation of Mn may change the morphology of A.nigerwill from pellate to filamantus.
316 steel contain 16% chromium, 10% nickel, 2% molybdenum
ReplyDeleteApplication :
-food preparation equipment paricularely in chloride environment
-laboratory benches and equipment
-coastal architecture panelling, railings , trim.
-chemical container, including for transport.
- Heat exchange.
- woven or welded screen for mining, quarrying and water filtration .
-Threaded fasterner.
- Springs
This comment has been removed by the author.
ReplyDeleteThe anabolism of A.niger is affected by manganese deficiency. This leads to breakdown of proteins and hence intracellular ammonium concentration increases.
ReplyDeleteThis further inhibits activity of phosphofructokinase contrasting citric acid inhibition and hence glycolysis inhibition too.
Manganese has also been proven to function in major cellular functions like cell wall synthesis , sporulation and production of secondary metabolites.
Ref : Braz. J. Microbiol. vol.41 no.4 São Paulo Oct./Dec. 2010
http://dx.doi.org/10.1590/S1517-83822010000400005
Why stainless steel no 316 is used in submerged fermentation?
ReplyDeleteIn submerged fermentation, spore inoculum is used. No 316 stainless steel is used to avoid corrosion.It contains molybdenum which provides resistance to corrosion.
https://books.google.co.in/books
Why manganese is important factor in citric acid production?
ReplyDeleteThe presence of manganese ions to citric acid fermentation was reported by Clark in 1966. As little as 1 µgl of manganese could completely ruined the production yield of and caused organism’s morphology to switch from microbial pellets, known as citric acid productive form, to unproductive filamentous growth.
In oposite of this in the most recend research by Berovic in 2006
it was found that when fungal biomass reaches its stationary phase even in a case when fed media contains unusually high ammounts of manganese ions up to 200 µg/l the presence of heavy metal ions do not effect on mycelial growth neither on citric acid biosynthesis.
Manganese deficient lower than 10 -7 M rised chitin and reduced β-glucan production. Manganese levels also affect lipid synthesis which in turn affects cell membrane composition. It also exhibits effects on DNA synthesis of A.niger. Under manganese limitation, DNA formation was not inhibited but RNA synthesis was impaired. On the other side manganese deficiency in A.niger cultivation also results in significantly lower lipid levels due primarily to reduction of triglycerides and with little effect on free acids and sterols.
https://www.researchgate.net
Clark observed that Mn concentrations as low as 3 mg/l drastically reduced the citric acid yield. Mattey and Bowes reported that the addition of 10 mg/l Mn2+ leads to a reduction in citric acid accumulation by 50%. Researches by Clark and Kisser confirmed the regulatory role of Mn2+ ions. The anabolism of A. niger is affected by manganese deficiency and/or limitation by nitrogen and phosphate. The breakdown of proteins under Mn deficiency results in high intracellular concentration of ammonium, which contrasts the citric acid inhibition of phosphofructokinase and hence glycolysis. Moreover, the combination of high concentrations of glucose and ammonium represses the synthesis of α-ketoglutarate dehydrogenase, hence inhibiting the catabolism of citric acid in the Krebs cycle and favoring its overproduction.
ReplyDeletehttp://dx.doi.org/10.1590/S1517-83822010000400005
Steel Grade 316 is the standard molybdenum-bearing grade amongst the austenitic stainless steels. The molybdenum gives 316 better overall corrosion resistant properties particularly higher resistance to pitting and crevice corrosion in chloride environments. It has excellent forming and welding characteristics. It is readily brake or roll formed into a variety of parts for applications in the industrial, architectural, and transportation fields. Grade 316 also has outstanding welding characteristics. Post-weld annealing is not required when welding thin sections.
ReplyDeleteGrade 316L, the low carbon version of 316 and is immune from sensitisation. Thus it is extensively used in heavy gauge welded components.
https://www.google.co.in/amp/s/www.azom.com/amp/article.aspx%3fArticleID=863
In comparison of citric acid fermentations in manganese-deficient and manganese-containing media showed that manganese strongly influences idiophase metabolism. In the presence of manganese, cell growth increases, sugar consumption is diminished and acidogenesis decreases drastically.Manganese deficiency was accompanied by a repression of anabolic and TCA-cycle-enzymes with the exception of citrate synthase.In the presence of manganese, no repression of enzyme synthesis was observed. The manganese deficiency mainly affects the operation of biosynthetic reactions in Aspergillus niger, thus leading to an overflow of citric acid as an end product of glycolysis.
ReplyDeletehttps://link.springer.com/article/10.1007/BF01390476
Why there should be low concentrations of metal ions during citric acid production?
ReplyDeleteTrace elements: Trace element nutrition is one of the most important factors affecting the yields (grams citric acid per gram sugar) of citric acid fermentation. Inparticular, the levels of manganese, iron, copper and zinc are quite critical. If the levels of these trace elements are correct other factors have less pronounced effects. Conversely, medium will not allow high production unless the trace element content is controlled carefully.
Manganese (Mn2+ ions) in the nutrient medium plays a key role in the accumulation of large amount of citrate by A. niger. When the Mn2+ concentration is maintained below 0.02 mM (which does not affect growth rate or biomass yield) large amounts of citric acid are produced (59). Clark et al. (12) observed 10% and 25% reduction in citric acid yield on adding 2 ppb and 100 ppb manganese to beet molasses respectively. Bowes and Matetey (5) also noted that by the addition of 10 ppm Mn2+ in the growth medium, citrate accumu- lation is effectively halved by A. niger. Orthafer et al. (54) found that manganese deficiency leads to signifi- cantly lower lipid content in A. niger whereas there were elevated lipid levels in manganese sufficient cultures. Jernejc et al. (30) stated that low mycelial lipid levels results in high yields of citric acid. Protein synthesis is also said to be inhibited by manganese deficiency
Tomlinson et al. (69) found that up to 1 mg iron per liter medium is essential for high yields of citric acid by A. niger, but that amounts in excess of this interferes with citric acid accumulation. Partial deficiency of iron has also been reported to be necessary for citric acid production by several workers The presence of excess iron favors the production of oxalic acid
Copper ions play an important role in reducing the deleterious effect of iron on citric acid production . It has also been reported that copper ions can suc- cessfully counteract addition of manganese to citric acid fermentation media and are inhibitors of cellular manganese uptake . Jernejc et al. (30) found that copper is an essential requirement for citric acid pro- duction and optimum concentration of Cu2+ is 40 ppm for high yield.
Low concentrations of zinc in the fermentation medium are generally favored in most citric acid pro- duction media (69). Chesters and Rolinson (9) reported that zinc deficiencies promote citric acid production. According to Wold and Suzuki (71), zinc plays a role in the regulation of growth and citrate accumulation. At high zinc levels (about 2 μM) the cultures are main- tained in growth phase, but when the medium becomes zinc deficient (below 0.2 μM) growth is terminated and citric acid accumulation begins. Addition of zinc to cit- rate accumulating cultures results in their reversion to growth phase.
Reference: https://www.journalagent.com/ias/pdfs/IAS_5_2_100_106.pdf
A. niger requires certain trace metals for growth (62). However, a limitation by other trace elements is necessary for citric acid production (92, 93), especially in the submerged fermentation. The metals that should be in limiting concentrations are Zn, Mn, Fe, Cu and heavy metals.
ReplyDeleteShu and Johnson (92) demonstrated that the optimal levels of Zn and Fe are 0.3 and 1.3 ppm, respectively. Whereas Clark et al. (11) observed that Mn concentrations as low as 3 mg/l drastically reduced the citric acid yield, Mattey and Bowes (64) reported that the addition of 10 mg/l Mn2+ leads to a reduction in citric acid accumulation by 50%. Researches by Clark et al. (11) and Kisser et al. (35) confirmed the regulatory role of Mn2+ ions. The anabolism of A. niger is affected by manganese deficiency and/or limitation by nitrogen and phosphate. The breakdown of proteins under Mn deficiency results in high intracellular concentration of ammonium, which contrasts the citric acid inhibition of phosphofructokinase and hence glycolysis. Moreover, the combination of high concentrations of glucose and ammonium represses the synthesis of α-ketoglutarate dehydrogenase, hence inhibiting the catabolism of citric acid in the Krebs cycle and favoring its overproduction.
Manganese has also been proven important in many cell functions, particularly in the cell wall synthesis, sporulation and production of secondary metabolites (93). Therefore, great care must be taken when choosing the ingredients of the medium, including the bioreactor construction materials, to ensure that traces of manganese do not reduce the yield of fermentation.
Reference : http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822010000400005
17MBT006
This comment has been removed by the author.
ReplyDeleteThis comment has been removed by the author.
ReplyDelete316 steel contain 16% chromium, 10% nickel, 2% molybdenum
ReplyDeleteApplication :
-food preparation equipment paricularely in chloride environment
-laboratory benches and equipment
-coastal architecture panelling, railings , trim.
-chemical container, including for transport.
- Heat exchange.
- woven or welded screen for mining, quarrying and water filtration .
-Threaded fasterner.
- Springs
There are two major numbering systems used by the steel industry, the first developed by the American Iron & Steel Institute (AISI), and the second by the Society of Automotive Engineers (SAE). Both of these systems are based on four digit code numbers when identifying the base carbon and alloy steels. The first digit on all alloy steel allow us to identify its class.
ReplyDelete3 as the first digit shows Nickle chromium steel.
Grade 316 is the standard molybdenum-bearing austenitic grade, second stainless steel in importance to 304. The molybdenum gives 316 better overall corrosion resistant properties than Grade 304, particularly higher resistance to pitting and crevice corrosion in chloride environments. It is readily brake or roll formed, welded, soldered and cut by both thermal and mechanical methods. The austenitic structure
gives excellent toughness, even down to cryogenic temperatures.
Austenitic steels are non-magnetic and non heat-treatable, and generally contain 18% chromium, 8% nickel and less than 0.8% carbon.
Mild steel is low carbon steel, typically contains 0.04% to 0.30% carbon content. There are also other types like Medium carbon steel and high carbon steel.
References:
https://www.metalsupermarkets.com/types-of-steel/
http://www.worldstainless.org/Files/issf/non-image-files/PDF/Atlas_Grade_datasheet_-_all_datasheets_rev_Aug_2013.pdf
https://www.thebalance.com/steel-grades-2340174
Roll no. 17mbt030
ReplyDeleteCHEMICAL COMPOSITION OF STEEL GRADE 318 (WEIGHT %)
C (％): ≤ 0.05
Si (％): ≤ 0.75
Mn (％): 0.60~1.00
P (％)≤: 0.040
S (％)≤: 0.015
Cr (％): 17.5 ~ 19.0
Ni (％): 10.8 ~ 12.5
Mo (％): 2.00 ~ 3.00
Other(％): Nb 0.30 ~ 0.65
Reference-http://www.ccsteels.com/Stainless_steel/1279.html
High concentrations of NH4+ and glucose also repress the synthesis of α-ketoglutarate dehydrogenase, inhibiting the citric acid catabolism via the Krebs cycle, leading to its accumulation.
ReplyDeleteReference-http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822010000400005
Accumulation of citric acid required deactivation of the TCA cycle enzymes which are responsible for its degradarion.
ReplyDeleteAcotinase and Isocitrate are the enzymes responsible for the biomass production.
In case of high carbon source the synthesis of α-ketoglutarate dehydrogenase inhibited due to which catabolism of citric acid is decreased and it leads to accumulation.
This comment has been removed by the author.
ReplyDeleteAlpha Ketoglutarate Dehydrogenase is a highly regulated enzyme which could determine the metabolic flux through the Krebs cycle. It catalyses the conversion of α-ketoglutarate to succinyl-CoA and produces NADH.α-KGDH is sensitive to reactive oxygen species (ROS) and repression of this enzyme could be critical in the metabolic deficiency induced by oxidative stress. This can decrease the growth rate of cells.
ReplyDeleteCatabolite repression due to presence of glucose or any other sugars at high concentrations can also be one of the reasons which affect both the increase of lag phase and decrease of growth rate.
Lag phase is where the cell's division and growth is delayed as the cells adapt to their surroundings. The enzyme here is dependent on ADP/ATP ratio and NADH. Hence due to increase in the oxidative stress and high concentrations of sugar the cells take a longer time to adjust in the environment which in the end leads to increased lag phase and citric acid accumulation.
This comment has been removed by the author.
ReplyDeleteA new article on 1,3 Propanediol, How addition of Xylan increases the formation of 1,3 PD from glycerol in Clostridium butyricum https://www.ncbi.nlm.nih.gov/pubmed/29534944
ReplyDelete17mbt024
ReplyDeleteCitric acid is accumulated more efficiently in the absence of alpha ketoglutarate dehydrogenase. Because, this multienzyme is to be inhibited, oxaloacetate and NADH proves helpful by inhibiting the activity of alpha ketoglutarate dehydrogenase.
Reference:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC214866/?page=6
Alpha ketoglutarate dehydrogenase (AKGDH) catalysis the oxidation of alpha keloglutarate to succinate, in the Tricarboxylic acid cycle (TCA cycle).
ReplyDeleteNow, in this experiment succinate, cis-aconitase, and oxaloacetate were seen as an inhibitor to AKGDH. Because of this, if pH range in the fermentation media is higher than ~ 2.8 and oxaloacetate accumulation starts, it will inhibit AKGDH activity and citric acid will not be produced efficiently by A.niger
In this experiment , when effect of concentration of carbon source was tested by taking glucose as the source, upto 1-3% (wt/vol) glucose did not influence AKGDH activity. However, in the presence of 10% (wt/vol) glucose, the specific activity of AKGDH dropped to only 23 % .
When an important enzyme's activity is curbed,then the cells take longer to adapt to the surrounding. Which is why the duration of lag phase increases during comparitively higher sugar concentration.
This leads to a lower growth rate.
NADH also is most likely to exert an inhibitory influence on AKGDH.
Reference : NCBI.NLM.NIH.GOV
PMID : 3968029
PMCID : PMC214866
BY
RAMYA J IYER
17MBT016
Alpha ketoglutarate dehydrogenase is highly regulated enzyme. It catalyses the conversion of alpha ketoglutarate to succinyl co-A and produce NADH.
ReplyDeleteDuring citric acid production high concentrations of NH4+ and glucose or other carbon source repress the synthesis and activity of α-ketoglutarate dehydrogenase , inhibiting the citric acid catabolism via the Krebs cycle, leading to its accumulation.
so repression of the activity will lead to less availability of NADH and this will results into the longer lag phase and reduction in the growth rate.
References:
https://link.springer.com/article/10.1007/BF00454376
https://www.researchgate.net/publication/7446883
Röhr M., Kubicek C.P. Regulatory aspects of citric acid fermentation by Aspergillus niger. Process Biochem. 1981;16:34–37
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3769771/#b87
BY
17MBT011
Alpha ketoglutarate dehydrogenase is considered to be a important and highly regulated enzyme as it helps in catalytic conversion of alpha keto glutarate to succinyl CoA and as a result it will produce NADH.
ReplyDeletethe NADH produced will have inhibitory effect on the enzyme AKGDH.
During the citric acid fermentation process, the higher concentration of glucose or any other form of sugar will affect the functioning of the enzyme AKGDH, as the functioning of the enzyme has been altered as a result its direct effect will seen on the cell growth which will directly lead to a longer lag phase because due to such stress conditions the cell are not able to grow properly as they use to grow previously,i.e the cells need much more time to get adapted to their new environment so automatically we could observe less microbial growth.
Reference
https://www.ncbi.nlm.gov/pmc/articles/pmc214866/? Page=6
The concentration of carbon source is also crucial for citric fermentation. The final yield of citric acid increases with initial sugar
ReplyDeleteconcentration in batch processes or glucose feeding rate in chemostat.
The highest productivities are usually achieved using 14-22% sugar, because such high concentrations of the carbon source lead to suppression of α-ketoglutarate dehydrogenase.
This results in a longer lag phase because the organism takes more time to get used to its new environment. This in turn results in a overall less growth of the microbial population.
Source:http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822010000400005
The enzyme alpha ketoglutarate dehydrogenase is a highly regulated enzyme in citric acid cycle. The catalysis of alpha ketoglutarate to succinyl coA is done by this enzyme and NADH is produced.
ReplyDeleteDuring high concentration of ammonium ions and sugar concentration, the activity of this enzyme is repressed and leads to its accumulation. As a result the catabolism of TCA cycle is inhibited and NADH is accumulated. This decreases the growth rate.
Alpha-ketoglutarate dehydrogenase (α-KGDH) is a highly regulated enzyme, which could determine the metabolic flux through the Krebs cycle. It catalyses the conversion of α-ketoglutarate to succinyl-CoA and produces NADH directly providing electrons for the respiratory chain. α-KGDH is sensitive to reactive oxygen species (ROS) and inhibition of this enzyme could be critical in the metabolic deficiency induced by oxidative stress. Activity of enzymes is repressed by accumulation of succinate. And higher concentration results in production of oxalate.
ReplyDeleteReference https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1569585
Kinjal. Parmar
17mbt023
Alpha-ketoglutarate dehydrogenase (alpha-KGDH) is a highly regulated enzyme, which could determine the metabolic flux through the Krebs cycle. It catalyses the conversion of alpha-ketoglutarate to succinyl-CoA and produces NADH directly providing electrons for the respiratory chain
ReplyDeletehttps://www.ncbi.nlm.nih.gov/pubmed/16321804
This comment has been removed by the author.
ReplyDeleteOrganism firstly utilize hexose sugar instead of pentose sugar because the end product of hexose sugar(pyruvate) is further oxidized completely, generating additional ATP and NADH in the citric acid cycle and by oxidative phosphorylation
ReplyDeleteThe pentoses, xylose and arabinose, are called non fermentable
ReplyDeletesugars.As the majority
of microorganisms, yeasts and bacteria, cannot utilize the
pentoses. As pentoses inhibit metabolism of organisms. The phenomena of CARBON CATABOLITE REPRESSION also makes the organism to prefer a hexose over pentose. sometimes the pentose catabolism is suppressed by glucose. Microorganisms regulate their catabolic activity in response to environmental nutrients. Because glucose is the most abundant carbohydrate monomer, bacterial metabolic pathways have evolved for glucose utilization and, therefore, efficient generation of energy is achieved through oxidation of glucose most bacteria possess alternative sugar utilization mechanisms to survive in competitive mixed sugar environments., the use of a secondary sugar is generally controlled in two layers. In the first layer, the transport of a secondary sugar is inhibited when a preferred sugar is present, a process called inducer exclusion (or repulsion). In the second layer, transcription of catabolic enzyme for a secondary sugar is regulated by two mechanisms. First, the expression of catabolic enzymes requires an inducer. Commonly, transcription of catabolic enzymes is suppressed by a repressor protein that is released by binding with the secondary sugar.
Why Pentose sugar is not prefered sugar for most of the microorganisms?
ReplyDeleteThere may be multiple reasons for this:
1. May be due to lack of Pentose transport system in organism during metabolism
2.Or may be because of the structural hindrance called furanose stable ring form of Pentoses instead of pyranose alpha and beta ring form of hexoses
3.Economically it will extend the process, glucose directly enters to glucose 6 phosphate and enter in cycle while pentose will take some extra path way before entering in main cycle.
4.Pentose pathway is not common pathway so could be possible to have lesser repeat of coding genes so less expression.
During the fermentation of sugars released by hydrolysis, microorganisms tend to selectively utilize a preferred sugar, usually glucose. This preferential consumption of sugar, termed carbon catabolite repression (CCR), makes it challenging to design and efficiently control the fermentation processes using lignocellulosic biomass as a feedstock.
ReplyDeleteMethods employed for detection of contamination during fermentation process:
ReplyDeleteSwab/Swab-Rinse Method. The swab method is applicable to any surface (flat or curved, horizontal, vertical, or sloped) that can be reached with hand-held sticks containing either cotton or alginate gauze swabs (or other approved alternatives). The swab technique can be used for hard-to-reach areas such as surfaces with cracks, corners, or crevices .A sterile swab, moistened in an appro- priate solution, is rubbed over a designated area of the contact surface. Sterile templates, with openings corresponding to the size of the area to be swabbed, are often very useful. The swab is transferred to its holder (test tube) with a known volume of a physiological neutral solu- tion and vigorously agitated (preferably in an automated shaker to ensure reproducibility). When calcium alginate swabs are used, the organisms are released into the diluent after dissolving the alginate, for example. in 3 % sodium hexametaphosphate solution. Samples of the solution, or decimal dilutions if necessary, are examined by, for example, the plate count method.
The cellulose sponge swab method is another technique that could be used to assess dairy equipment hygiene. Little pieces of sponge (free from bacterial inhibitors) held by tweezers or by hand (using sterile gloves) are used to sample surfaces.This technique is particularly useful to examine large surface areas. Numbers of organ- isms recovered by alginate swabs are reportedly higher than those obtained by cotton swabs . The reproducibility of the swnb/swab-rinse techniques is variable due to the unreliable efficiency of swabbing, and the proportion of bacteria removed from the surface is unknown. Furthermore, it is highly operator-, day-, and time- dependent .The swab method is, despite its limitations, very useful and almost universally applied in the dairy industry .The swab and rinse methods may also be supplemented by a bioluminescence test for total adeno- sine-5triphosphate (ATP) ,whereby an indication of the state of hygiene of the plant surface is acquired. Obviously. the readings are not intended to correlate with the microbial count, but there is an excellent correlation between clean surfaces and low levels of ATP.
Surface Rinse Method. The effectivity of cleaning and sanitation of containcrs and equipment can be assessed by rinsing the container or equipment with a measured volume of sterile water or Ringer’s solu- tion and analyzing the sample for total bacterial numbers or the pres-ence of different types of organisms. The rinse (solution) method is more appropriate for assessing internal surface contamination of con- tainers. In cases where the volume of the rinse is large, or the microbial load is low, it is advisable to use the membrane filter technique whereby a known volume of the rinse sample is filtered through an appropriate membrane (generally 0.45pm), retaining any microorganisms that may be present. The mem- brane is placed onto the surface of a pre-poured agar plate and inocu- lated, and visible colony growth is observed between 48 and 72 h. Rinse water could also be examined by the direct epifluorescent filter tech- nique (DEFT), using fluorescent dyes and fluorescence microscopy .An advantage of the DEFT is that results can be obtained within 25-30min.
Reference: Dairy Microbiology Handbook: The Microbiology of Milk and Milk Products, 3rd Edition. Edited by Richard K. Robinson
Chapter 14
microorganisms are known to rapidly adjust their metabolism in response to environmental changes such as the presence of a contaminant organism. Changes in microbial metabolism are quickly detected through changes in their metabolic footprint profile. The metabolic footprint is the profile of extracellular metabolites resulting from nutrient uptake, extracellular biochemical reactions, and the secretion of metabolic products performed by a population of cells in the environment where they grew. This metabolic footprint is highly specific to the genetic background of the cells and the environmental conditions under which they grew. Thus, through metabolic footprint analysis one is able to distinguish different metabolic states of the cells, different microbial species, and even different strains or mutants from the same species. Metabolic footprinting therefore has the potential to reveal unique differences in the profiles of metabolites of fermentation broths that result from the presence of contaminant cells.
ReplyDeletereference:An Exometabolomics Approach to Monitoring Microbial Contamination in Microalgal Fermentation Processes by Using Metabolic Footprint Analysis
Tiffany Sue,1 Victor Obolonkin,1 Hywel Griffiths,2 and Silas Granato Villas-Bôas1,*
The anabolism of A. niger is affected by manganese deficiency. The breakdown of proteins under Mn deficiency results in high intracellular concentration of ammonium, which contrasts the citric acid inhibition of phosphofructokinase and hence glycolysis. Moreover, the combination of high concentrations of glucose and ammonium represses the synthesis of α-ketoglutarate dehydrogenase, hence inhibiting the catabolism of citric acid in the Krebs cycle and favoring its overproduction.
ReplyDeletereference:
Biotechnological production of citric acid
Belén MaxI; José Manuel SalgadoI; Noelia RodríguezI; Sandra CortésI; Attilio ConvertiII; José Manuel DomínguezI,
Some of the listed methods to detect contamination in culture:
ReplyDelete1. Karyotyping to determine modal chromosome number and the presence of any unique marker chromosome number of species.
2. Electrophoresis and isoenzymes analysis to generate a protein “fingerprint” that can be used to determine species for contamination.
3. Immunological or biological techniques to detect the markers that are unique for the species specified.
4. DNA fingerprinting that detect both intracellular and intercellular species contamination.
Some of the methods to detect contamination during fermentation process-
ReplyDelete1.polymerase chain reaction (pcr)
2.multiplex pcr
3.real time pcr
4.nucliec acid sequence based amplification (nasba)
5.loop mediated isothermal amplification.
6.optical,electrochemical and mass based biosensors.
7.An exometabolomics approach to monitoring microbial contamination in microalgal fermentation process.
https://www.ncbi.nlm.nih.gov/
QUESTION : Contamination Detection Methods in Fermentation.
ReplyDeleteANSWER : 1)Gas chromatography-mass spectrometry (GC-MS)-based
Metabolic footprint analysis as a rapid and reliable
method for the detection of microbial contamination
in fermentation processes.
2) Mass spectrometry mehtod
3) NIR(near infrared) spectroscopy
References:
https://www.ncbi.nlm.nih.gov/pubmed/21890679
https://www.sciencedirect.com/science/article/pii/0167701292900423
Tsenkova, R., Atanassova S., Kavano, S., and Toyoda, K. (2001). Somatic cell count determination in cow`s milk by near-infrared spectroscopy: A new diagnostic tool, J. Anim. Sci., 79, 2550-2557
17 MBT024
ReplyDeleteMethods to detect contaminations in fermentation broth:
1) Near Infrared spectroscopy.
2) Gas chromatography coupled with Mass spectroscopy based.
Reference: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3209156/
This comment has been removed by the author.
ReplyDeleteWhat is immobilization? Name the methods used for microbial cell immobilization.
ReplyDeleteImmobilization is the method of entrapping/attaching the microbial cells in a suitable matrix.
Different methods such as encapsulation, gel entrapment, covalent bonding, cross linking and adsorption is carried out
to prepare immobilized cells.