NAME: UZOMA SYLVERLINE CHIDALU

DEPARTMENT: BIOTECHNOLOGY

MATRIC. NO:20221200010

COURSE: BTG 305(MICROBIAL TECHNOLOGY)

LEVEL:300L

LECTURER:MR. AHAMEFULE

DATE: JANUARY 2025

ASSIGNMENT.

1.UTILIZATION OF MICRO ORGANISMS OF BEER AND WINE.

2.DIFFERENTIATE BETWEEN BATCH AND CONTINUOUS

FERMENTATION.
 Table of Contents.

Abstract.

1.0 General Introduction.

1.1 Background of the study.

1.2 Statement of problem.

1.3 Purpose

1.4 Significance.

1.5 Method of study.

2.0 Batch Fermentation.

2.1 Meaning

2.2 Types(Aerobic, Anaerobic)

2.3 Advantages

2.4 Disadvantages

3.0 Continuous Fermentation .

3.1 Meaning.

3.2 Types (Chemostat,Turbidostat).

3.3 Advantages

3.4 Disadvantages

4.0 Difference between Batch and Continuous Fermentation.

5.0 Conclusion.

6.0 Reference.
ABSTRACT:

Fermentation is a crucial process in various industries, including food,

pharmaceutical, and bio-fuel production. Two primary modes of fermentation are
batch and continuous. This paper aims to differentiate between batch and continuous
fermentation, highlighting their principles, advantages, and disadvantages. A
comparative analysis of the two modes will provide insights into their applications
and suitability for various industries.
 SECTION 1: GENERAL INTRODUCTION

Background of the Study

In various industries producing food, drugs, and beverages and biofuel production, the

process of fermentation cannot be overlooked: for it is a very important process that is

required for the production of these final products. It involves the conversion of

sugars into products such as ethanol, butanol, and other valuable compounds through

the actions of micro-organisms. To this effect, there are two common fermentation

techniques employed in industrial processes- batch and continuous fermentation.

Statement of the Problem

To close the knowledge-gap that hinders the optimization of fermentation processes,

leading to reduced productivity, efficiency, and product quality; since there is a lack of

comprehensive understanding between these modes of fermentation, mainly in terms

of their operational characteristics, advantages and limitations.

Purpose of the Study

The purpose of this study is to make a comparative analysis in order to provide a

comprehensive understanding of these two processes of fermentation.

Method of the Study

The research method used here is comparative analysis. Research materials from

journals and internet sources.

Significance of the Study

This study aims to contribute to the development of more efficient and productive

fermentation processes, which can have significant impacts on various industries,

including biofuel production, food processing and drug production.

 SECTION 2: Batch Fermentation

Fermentation makes use of a living microbial cell suspension. It produces various

valuable products through fermentation of the raw material or substrate. This is

because in fermentation, a little inoculum converts carbohydrates into acids and

alcohols. This process takes place under anoxic conditions.1

Fermentation involves open and closed cultivation methods. Let us begin with the

closed system- batch fermentation.

A batch fermentation system is a closed system. It involves the fermentation of the

substrate into products by microbial cells.2 it is a technique in which microbial cells

grow and multiply to convert substrates into products. This is performed using the

stirred tank fermentor. Batch fermentation itself clears that it involves batch-wise

fermentation of the specific media. Microbial cells harness the added nutrients.

Thereafter, they ferment raw materials into desired products within a predetermined

fermentation time.

This type of fermentation follows a principle:

It follows a closed system fermentation. All the materials needed before the

fermentation starts should be added; and its incubation proceeds for a specific

fermentation period. During this period, nothing can be added nor added. Batch

culture fermentation involves the commercial production of various products. This

process takes place in separate batches.

Here, other factors become limiting as we supply limited nutrients for microbial

growth. As a result, the bacteria show a sigmoid growth curve with four distinct

phases.3 These phases include:

1
https://biologyreader.com> batch-fermentation.
2
https://biologyreader.com> batch-fermentation.
3
https://biologyreader.com> batch-fermentation
a) Lag phase: in this phase, microbial cells adapt to the conditions within the

bioreactor. Here, they tend to grow in size and not in number.

b) Log phase: After two hours of the lag phase, cells enter into the log phase. Here,

they consume the nutrients to become metabolically active at a rapid pace. This leads

to the production of primary metabolites. There is also an exponential increase in

number of bacterial cells. The concentration of nutrients, microbial cells and products

in the reaction mixture vary with time. No fresh media during the course of

fermentation can be added; and at this stage, the production of secondary metabolites

occur.

c) Stationary Phase: it is at this stage that the production of secondary metabolites

occur.

d) Decline phase: at last, cell growth declines due to the lack of nutrients and

accumulation of toxic wastes

Types of Batch Fermentation

1. Aerobic Fermentation

Aerobic fermentation occurs in the presence of oxygen. Wine, beer and acetic acid

vinegar needs oxygen in the primary or firsts stage of fermentation. For example;

preparation of acetic acid vinegar is done by exposing the surface of the vinegar to

oxygen as much as possible, which helps in creating healthy, flavorful vinegar with

the correct pH.4

2. Anaerobic Fermentation: It is a method in which cells are used to extract energy

from carbohydrates when oxygen is not available in the surrounding environment.

This process can follow glycolysis as the next step in the breakdown of glucose and

4
Sourvinos, George (2022). Methods involved in Aerobic and Anaerobic Fermentation. J Prob Health.10: 277. pg.1.
other sugars to produce molecules of Adenosine TriPhosphate (ATP) that create an

energy source for the cell.5

Advantages of Batch Fermentation

a) It is easy to set up and run

b) It has wide applicability in laboratories and industries

c) There is less chance of possibility in the aspect of contamination since it is a closed

system.

d) It is easier in comparison to the continuous culture. This is because the setup can be

reinstalled if contamination occurs.

e) The complete conversion of a substrate into a product is possible.

Disadvantages

a) It requires high cost labour and involves batch-to-batch variability

b) It involves high downtime between two consecutive batches

c) The isolation of product is difficult because the fermentation broth contains

nutrients, reagents, cell debris and toxins.

Application

This technique helps microbiologists and biotechnologists to observe the metabolic

activity of the bacteria. It also helps in studying the cell physiology of microbes.

It is also efficient for the production of secondary metabolites such as antibiotics.

5
Sourvinos, George (2022). Methods involved in Aerobic and Anaerobic Fermentation. J Prob Health.10: 277. pg.1.
 SECTION 3: CONTINUOUS FERMENTATION

This is a type of fermentation that involves the addition of the substrate in an

unbroken stream and withdrawal of fermented medium in the same manner. 6 It is an

open operation system with continuous discharge of the solution in the system. Micro-

organisms and sterile nutrients are added homogeneously to the bio-reactor,

continuously, while nutrient solution and micro-organisms are transformed

equivalently in the system.7 In this type of fermentation, microbial population can be

maintained in an exponential growth for a long time. This is because this exponential

growth of the culture is continuous until a time when the fermentation vessel is totally

filled with the fermentation media.8

On the other hand, the rate of addition of fresh growth medium determines the rate of

growth because the fresh medium always contains a limiting amount of essential

nutrient.

Types of Continuous Fermentation.

Continuous fermentation may be of many types with respect to the equipment used

and with respect to the flow of fermenting media through that equipment. Therefore,

the chemostat and turbidostat are the major types of this fermentation method.

a) Chemostat: This fermentation feeds nutrient medium into the culture vessel at the

same rate as the medium containing the micro-organisms is removed. Here, the

medium contains one essential growth nutrient like amino acid in a limiting amount;

and because a sub-maximal amount of the essential growth nutrient is used at any

6
Maxon, D. William. Microbiologial Process Report. Continuous Fermentation (A Discussion of Its Principles and
Applications). Research Laboratories, The Upjohn Company, Kalamazoo, Michigan. Received for publication
October 28, 1954. p.110.
7
https://www.sciencedirect.com >continuous fermentation- an overview. Accessed January 13, 2025.
8
https://www.sciencedirect.com >continuous fermentation- an overview. Accessed January 13, 2025.
given time, a constant population of the microbial cell is maintained in a constant

volume.9

b) Turbidostat: This is a continuous microbiological culture device, similar to a

chemostat or an auxostat which has feedback between the turbidity of the culture

vessel and the dilution rate.10 A turbidostat dynamically adjusts the flow rate (and

therefore the dilution rate) to make the turbidity constant. At equilibrium, operation of

both the chemostat and turbidostat are identical.

Advantages of Continuous Fermentation

a) Isolation of an organism capable of growth on a simpler medium make basic of

cheaper commercial process and the process should be more resistant to

contamination

b) There is a marked reduction in processing time, with the same holding capacity of

equipment or, alternatively, a marked reduction in equipment size for the same rate of

production.11

c) As a consequence of steady-state operation, the product can be expected to have a

greater homogenity.12

d) It is more adaptable to instrumental control, and it is better integrated into such

other parts of the over-all process as the preparation of medium and the recovery of

product, which may be operated more economically and efficiently in a continuous

manner.13
9
https://micobiologyclass.net> continuous and semi-continuous fermentaion . Accessed January 13, 2025
10
Kamat, Priya. Continuous and Batch Fermentation. Centurion University of Technology and Management.
11
Maxon, D. William. Microbiologial Process Report. Continuous Fermentation (A Discussion of Its Principles and
Applications). Research Laboratories, The Upjohn Company, Kalamazoo, Michigan. Received for publication
October 28, 1954. p.110.
12
Maxon, D. William. Microbiologial Process Report. Continuous Fermentation (A Discussion of Its Principles and
Applications). Research Laboratories, The Upjohn Company, Kalamazoo, Michigan. Received for publication
October 28, 1954. p.110
13
Maxon, D. William. Microbiologial Process Report. Continuous Fermentation (A Discussion of Its Principles and
Applications). Research Laboratories, The Upjohn Company, Kalamazoo, Michigan. Received for publication
October 28, 1954. p.110.
Disadvantages

a) Set up is more difficult.

b) Maintenance of required growing conditions can be difficult to achieve.

c) There would be great loss of huge volumes of products in the event of

contamination.

SECTION 4: DIFFERENCES BETWEEN BATCH AND CONTINUOUS

FERMENTATION
Now, let us know the differences between batch and continuous fermentation.

Batch Fermentation Continuous Fermentation

1. It is a closed operation system. It is an open operation system.

2. It is used to extract secondary It is used to extract primary metabolites

metabolites such as antibiotics such as amino acids and proteins.

3. The turnover rate (formation of The turnover rate is high.

product) is low.

4. All the nutrients are added at once in Nutrients are added throughout the batch

the beginning.

5. Product is extracted at the end of the Product is continuously removed while

batch. the batch is operating

6. Since it is a closed operation system, It has a high chance of contamination

the rate of contamination of products is since it is an open system.

less.

7. The growth conditions can be changed The growth conditions have to be

by altering pH and dissolved oxygen. maintained throughout the operation of

the batch.

8. Nutrients are consumed at a slower Rapid rate of nutrients consumption.

rate.

9. Product life span can be 1-2 years Longer than batch process

SECTION 5: CONCLUSION

Fermentation is the metabolic process of the breakdown of organic molecules in the

absence of oxygen with the aid of micro-organisms. It is mostly used in industrial

processes to produce beverages and food molecules. Among the modes of

fermentation include: the batch and the continuous modes of fermentation.

Batch fermentation offers flexibility and ease of operation, while continuous

fermentation provides higher productivity and efficiency. The choice between batch

and continuous fermentation depends on factors such as the type of micro-organism,

substrate and desired product.

REFERENCES

https://biologyreader.com> batch-fermentation

https://micobiologyclass.net> continuous and semi-continuous fermentaion .

https://www.sciencedirect.com >continuous fermentation- an overview.

Kamat, Priya. Continuous and Batch Fermentation. Centurion University of

Technology and Management.

Maxon, D. William. Microbiologial Process Report. Continuous Fermentation (A

Discussion of Its Principles and Applications). Research Laboratories, The Upjohn

Company, Kalamazoo, Michigan. Received for publication October 28, 1954.

Sourvinos, George (2022). Methods involved in Aerobic and Anaerobic

Fermentation. J Prob Health.10: 277.