The document discusses fed batch culture techniques in microbiology. It begins with an overview of batch culture where nutrients are added only once at the start of cell culture. Fed batch culture involves adding nutrients before and during cell culture to overcome issues like catabolic repression and substrate inhibition seen in batch culture. Catabolic repression occurs when catabolites prevent the formation of enzymes needed to break down alternative nutrients. The document uses E.coli grown on glucose and lactose to illustrate this phenomenon. Substrate inhibition happens when the substrate concentration exceeds the optimal level, inhibiting the reaction. Fed batch culture allows controlling nutrient levels to maximize cell growth and product yields. Its advantages over batch culture are highlighted.

1. Reaacredited with B grade with a CGPA of 2.71 in the second cycle of NAAC
affiliated to manomanium sundaranar university, tirunelveli.
Post graduate & Research Centre – Department of microbiology
(government aided)
I SEM CORE: MICROBIAL PHYSIOLOGY AND METABOLISM (ZMBM13)
UNIT-5
FED BATCH CULTURES
G.S.AMRISH VARSHAN SUBMITTED TO
REG NO:20211232516102 GUIDE:DR.S.VISWANATHAN
I M.SC MICROBIOLOGY ASSISTANT PROFFESSOR&HEAD
ASSIGNED ON: 08/12/2021 SPKC - ALWARKURUCHI

2. SYNOPSIS
• Introduction to fed batch culture
• Catabolic repression
• E.coli concept
• Substrate Inhibitor
• Need of Fed-Batch culture
• Advantages of Fed-Batch culture

3. What is Fed-Batch culture
• In general batch culture is a technique were the bacteria is grown in a large
scale to produce products
• In the batch culture there will be no interaction from the environment until
the product form
• In batch culture the nutrient is added only once and final harvest only takes
place
• But in fed batch culture we add nutrients before the start of the process as
well as during the process of cell culture

4. Catabolic Repression
• Catabolism Catabolites
• Breakdown of complex compounds into simpler compounds is called
catabolism the simpler compounds is called catabolites
• Repression means (or) is to control the production of some thing
• So catabolic repression is to control the production of some enzyme

5. E.Coli
E.coli
Glucose
E.Coli
E.Coli
Glucose
fructose
E.Coli
Fructose
• In the first case E.coli growing in a glucose containing medium it produces the enzyme
which breakdown the glucose
• In the second case E.coli growing in a medium containing both glucose and fructose but
it prefers to take glucose and the enzyme responsible for breakdown of glucose is produced
• In the third case only lactose is present and E.coli produce the enzyme which is responsible
of breakdown of lactose

6. • So as we seen the example of E.coli in the absence of glucose only the lactose
digesting enzymes are produced
• So we clearly seen that the catabolites of glucose are preventing the formation of
lactose digestive enzyme
• This phenomenon is known as Catabolite repression.

7. Substrate Inhibition
• It is a phenomenon in which substrate itself is going to inhibit the reaction
• The increasing concentration of substrate beyond a optimum level will
inhibit the reaction
• Vmax at which the velocity of the reaction is maximum and after that
concentration of substrate beyond the optimum level there will be no
binding and it will be zero

9. • In substrate inhibition the inhibitors and the substrate have similar site of binding
• Only the difference is, the substrate binding site have more affinity towards the
substrate and site of inhibitors have low affinity towards the substrate
• The substrate will bind in the inhibitor site when the concentration of the
substrate is beyond the optimum level
• This phenomenon is known as substrate inhibition

10. Needs of Fed-Batch culture
• The main need is to overcome the Catabolic repression and the Substrate
inhibition
• It can be achieved by preventing the excess amount of nutrients in the
bioreactor
• So that in fed culture we only add nutrients when the bacterial cell needs it
• To also overcome substrate inhibition, by only providing sufficient amount
of substrate

11. Advantages of Fed-Batch culture
• It helps us to get high cell density ,the cell growth will decreases if they face
depletion of nutrients (or) lack of nutrient
• In Fed-Batch culture we periodically add nutrients when there is nutrients
deployments, so that the cell will start to proliferate more
• It enhance the growth of the cell which leads to more amount of biomasses
and products
• Useful when the products or biomass yields high at low substrate

12. SKILL GAINED THROUGH SEMINAR
• COMMUNICATION SKILL
• GAINED MORE SUBJECT KNOWLEDGE
• INCREASING OF THE CONFIDENCE LEVEL
• PERSONAL SKILL
• SUBJECT PLAN

15. REFERENCE
• Youtube
• Prescot
• https://en.wikipedia.org/wiki/Fed-batch_culture-Wikipedia
• https://www.slideshare.net/RengeshBalakrishnan/batch-fedbatch-continuous-cultivation-57209876
• Slideshare

16. THANK YOU
The Chairman.
The secretory.
Management committee.
The principle, Sri paramakalyani college.
The head-Department of microbiology.
The staff members- Department of microbiology.