These slides consist of brief introduction of industrial microbiology along with the steps in the production of some fermented products.

1. INDUSTRIAL MICROBIOLOGY
• INTRODUCTION: Branch of Microbiology which deals with the study and use of
various micro-organisms that are responsible for the production of many products
such as alcoholic products, antibiotics, enzymes, vaccines.
• Use of Genetically Modified organisms – An advancement in the field of Industrial
Microbiology
• Increased productivity.
.

2. Applications of Industrial Microbiology
 Bacteria, Fungi, Yeast etc. are used commonly in the production of various
fermented products like wine, yogurt etc.
 Strains of Corynebacterium glutamicum have been used in the production of
the amino acid, L-glutamate.
 Production of food and dairy products. Cheese, yoghurt, alcoholic beverages,
coffee, tea, vitamins etc are some of the examples.
 Production of vaccines is another important application of industrial
microbiology.
 Antibiotics are another important products produced by using micro-
organisms.

3. ETHANOL PRODUCTION
 INTRODUCTION: Ethanol is an important industrial solvent which has many industrial, medical
and commercial uses.
 MICRO-ORGANISMS: Saccharomyces Cerevisiae, Saccharomyces uvarum, S. carlsbergenesis,
Candida brassicae(two different types of Yeast species), bacteria (Zymomonas mobilis) .
 RAW MATERIALS: Sugarcane molasses in case of Saccharomyces Cerevisiae
whey from milk is used as the raw material in case of Kluyveromyeces fragilis
Pentose sugars are used in case of Bacillus(bacteria) and fusarium species.

4. SACCHAROMYCES CEREVISIAE
 Saccharomyces cerevisiae is also popularly called as the Brewer’s Yeast.
 First isolated from the skin of the grapes.
 Most commonly used in the process of fermentation.
 considered as the model organism in molecular and cell biology.
 This Yeast species produces two different types of products based on the presence(Aerobic) or
absence(Anaerobic) of Oxygen. Under anaerobic conditions, The glucose present within the
molasses(sugar sources) to ethanol.

5. STEPS IN THE PREPARATION OF ETHANOL FROM
SUGARCANE MOLASSES
 Dilution of molasses: Molasses are the remaining fluid left after the crystallisation of sugarcane.
This is first diluted with water.
 Addition of Ammonium sulphate: Adequate nitrogen is supplied by the addition of ammonium
sulphate to the yeast involved in this.
 Addition of sulphuric acid: The fortified molasses are then acidified using sulphuric acid, which
removes unwanted bacteria.
 Fermentation: To the above mixture, is added the yeast(saccharomyces cerevisiae) and is left
for 2-3 days for the desired reaction to take place in the presence of the enzymes of the yeas
 Fractional distillation: The ethanol so formed above is then purified by using the process of
fractional distillation and is converted to 92% pure alcohol known as the rectified spirit or
commercial alcohol.

6. BIOCHEMISTRY OF ETHANOL
 Molasses contain sugars which are converted into ethanol in the presence of enzymes such as
zymase supplied by the yeast under anaerobic conditions.
 The total process occurs in two steps:
 Firstly conversion of glucose to pyruvate by the process of glycolysis.
 pyruvate is then converted to ethanol and carbon-dioxide through fermentation.
 In the presence of oxygen, the pyruvate formed in the first step enters the mitochondria to
undergo the further steps of aerobic respiration.
 Under anaerobic conditions, the pyruvate is first converted to acetaldehyde which is then
converted to ethanol and carbon-dioxide in the presence of zymases.

7. ANTIBIOTICS
 Introduction: Substances which kill or inhibit the growth of micro-organisms.
Penicillin is an example discovered by Alexander Fleming in 1929.
 Action of the antibiotics:They can either destroy the bacterial cells completely or can affect their metabolism.
They can be used either externally as an ointment or can also be given for internal use either orally or through injections.
 Types of antibiotics: Penicillin(penicillin, amoxycillin
Cephalosporin (cephalexin)
macrolides(Erythromycin)
Tetracycline(tetracycline, doxycycline)
Broad range antibiotics(can kill both gram-positive and gram-negative bacteria eg. Ampicillin)
Narrow range antibiotics(can kill only a particular type of bacteria(eg. Azithromycin).
 Raw materials for the production of antibiotics: Nutrient media like a nutrient broth(liquid media)
carbon source(such as molasses)
Nitrogen sources(such as ammonia)
some of the trace elements like phosphorous , zinc etc. which help in the growth of these microbes.

8. STEPS IN THE PREPARATION OF ANTIBIOTICS
 Starting the culture: To initiate the growth of the desired micro-organism, A starter culture is taken from the previous cold-
stored organism and is grown on the agar plate.
A pure culture is isolated and is transferred along with the required nutrients and food into a shake flask to obtain the
desired suspension which is then transferred into the seed tank.
The seed tanks contain all the necessary vitamins, nutrients, carbon, nitrogen sources for the growth of the cultures.
A proper supply of air is also done to these tanks along with constant mixing of the contents and after 24-48 hours, these
contents are transferred to the primary fermentation tank.
 Fermentation: The fermentation tank has an environment where the micro-organisms can excrete the desired antibiotic.
These tanks have a capacity of about 30,000 gallons and to maintain proper growth, and pH, the required nutrients and
either acids or bases are added to it.
The temperature of these tanks is maintained around 23-27.2 ° C.
 Isolation and purification: The desired antibiotic will be produced in maximum amounts after 3-5 days.
Water soluble antibiotics are isolated by using Ion-exchange method and the Oil-soluble ones are extracted by using solvent-
exchange methods.
 Refining: The antibiotics can be used in various forms such as the Intravenous bags or syringes, ointments, gels, capsules
etc. Based on the usage of the antibiotic, the powdered antibiotic is converted to any of the above said forms and finally
sent for packing and delivery to the pharmacy, hospitals etc.
 Quality control: The equipment used in the entire process are steam sterilised and also frequent checks are made about the
purity of the microbial culture.
pH, melting point and moisture content of the finished product are checked before dispersing the final product to ensure
purity and safety.

10. VACCINES AND THEIR PREPARATION
 Vaccines- killed or inactivated micro-organisms given to the healthy
individuals to protect them from various harmful infections.
 They are given either in the form of injections or in the form of drops, in
different periods after birth.
 In the year 1796, Edward Jenner laid the foundation of the concept of
vaccination and further studies were also made by louis Pasteur on the
bacteria which caused anthrax and also a viral infection rabies. He developed
vaccinations against these infections afterwards.
 There are several strains of a single type of virus usually and the vaccines
using all the possible strains are prepared to provide protection against
maximum number of such harmful viruses or bacteria.

11. STEPS IN THE PRODUCTION OF
VACCINE
 The following steps are adopted in the manufacture of vaccines on large-scale:
 The production of a vaccine against a particular virus often starts with a small sample or seed of the virus, which is
maintained under appropriate conditions(frozen conditions) using sensors which are then used to produce several
hundred litres of the vaccine.
 The virus sample is then defrosted, warmed and is added to a cell-factory. Every virus needs a particular type of
medium for its growth, which typically contains a host for its reproduction along with proteins and other necessary
nutrients. The cell-factory is supplied with this medium and proper temperature and pH are maintained to grow the
virus to the required amount.
 The container in which the viruses are grown is equipped with a number of valves, tubes and sensors for supplying the
required nutrients to it and also to withdraw the intermediate product when it is ready. The sensors help in
monitoring the temperature and pH of the growing viruses.
 The viruses are then separated and placed into a secondary medium which is also supplied with the similar type of
growth media, nutrients for additional growth of the viruses. The viruses are made to grow attached to the beads,
which are added to this secondary medium. Beads provide a larger area for the growing viruses to attach themselves
and to produce large quantities of the virus.
 Followed by production of the viruses in large amounts, separation of these viruses from the beads to which they are
attached takes place. This can be done in various ways such as passing them through a filter which retains back the
viruses allowing the beads to pass through it, centrifugation, flushing the beads mixture with another media which
flushes off the viruses from them etc.

12.  The next step in the production of a vaccine is the selection of the required strain of the
virus of which the vaccine is being prepared. Vaccines may be either killed or attenuated,
depending on their type. Attenuation is the process of inactivation of the virus using various
techniques and killed vaccines contain killed viral strains. The process of attenuation is done
before growth of the virus is started.
 Carefully selected strains of the desired virus are grown repeatedly in different types of
media and only some viruses are suitably attenuated to be used as vaccine as some of the
strains are become more powerful by their repeated growth and some of them become very
weak to be used as vaccine.
 Vaccines are then separated from the growth medium and several types are combined before
packaging.
 Quality control is an important step in the entire process which includes the sterilization of
the equipment used in the process using an autoclave. Also the persons working for this wear
proper clothes and take measures to protect themselves from being attacked by these
viruses. The department of Food and Drug Administration(FDA) should approve the
manufacturers and only the licensed ones can go ahead. The FDA continuously monitors each
and every step of the process and also maintains record for each step.