MICROBES IN PRODUCTION OF ANTIBIOTICS, ORGANIC ACIDS , BIO ETHANOL

By,Pillai Aswathy viswanathPG 1 BotanySt. Thomas college kozhencherry

INTRODUCTION The term microbe was coined to refer

collectively to the microscopic organisms, including bacteria, fungi, protozoa, and viruses. 

Micro organism produced a wide variety of substance in the culture during their growth

The production of such substances is due to the fermentation of food substance found in the feed-stock

Fermentation :- is an anaerobic breakdown of complex organic material by the action of anaerobic micro organism

it also denotes some other process in which the break down of organic substance take place in the presence of oxygen

In industries, large culture vessels are designed to carry out fermentation in large scale. these culture vessels are called fermenters or bioreactors

The bioreactors provide the controlled environment necessary to bring about the better growth of the microbes

The fermentation process result in the production of a wide class of organic compounds

The important fermentation products antibiotics organic acid amino acid enzymes bioethanol

MICROBES IN PRODUCTION OF ANTIBIOTICS

Antibiotics are substances produced by the micro organism that inhibits the growth of microorganism or kill another micro organism

They are used in the treatment of many pathogenic diseases in man and other organism

A wide class of fungi and bacteria produced antibiotics in the culture

Most antibiotics are industrially produced by microbial fermentation

Production of penicillin:- Penicillin is commercially produced in

the industry by culturing the fungus Penicillium chrysogenum or Penicillium notatum

The fungus can be cultured in two methods:-

surface culture method submerged culture method

SURFACE CULTURE METHOD In surface culture

method ,the fungus is cultured on the surface of a liquid medium with out agitation

After an appropriate incubation period the pencillin is extracted from the medium

SUBMERGED CULTURE METHOD

The fungus is grown in a liquid medium which is vigorously aerated and agitated

After an appropriate incubation period ,the penicillin is separated from the medium

Today penicillin is produced by this method.

The fungus grows as pellets In the seven days,the fermentation

process is completed and penicillin is produced in the medium

The mass of the fungus is seperated from the culture medium by centrifugation

Penicillin is extracted from the clear fluid

Production of streptomycin:- Streptomycin is an antibiotic It is produced by the fungus,

Streptomyces grises Streptomycin is produced by

fermentation. The medium for streptomycin

production contains soybean meal,glucose and sodium chloride

The pH of the medium is adjusted to 7.8-8.0

During the first phase there is a rapid growth of microbe with the production of mycelial biomass

The medium needs to be constantly aerated to achieve maximal production of streptomycin

The fermentation process takes about 10 days to complete

After completion of the fermentation , streptomycin is recovered from the culture medium

The recovery and purification consists of adsorbing streptomycin on to the charcoal

MICROBES IN PRODUCTION OF ORGANIC ACID

An organic acid is an organic compound with acidic properties

Different groups of organism produced organic acid in the culture during their growth

Production of citric acid :- Citric acid is one of the organic

acids found in many fruits especially in citrus fruits

It has been extracted from citrus fruits

But in recent years, citric acid has been manufactured from microbial cultures

The following microbes accumulate large proportion of citric acid in their cell:-

Bacillus subtilis Penicillium restrictum Aspergillus niger Aspergillus wentii

The citric acid production requires aerobic fermentation

The fungus can be cultured in two methods:-

Liquid surface culture Submerged culture

LIQUID SURFACE CULTURE In this method ,sterilized medium

is filled in a tank fermenter and A.niger is inoculated in to the tank

Fermentation is effected at 27-33°c temperature

The spores germinate in 24 hours and form a mycelial cover that float on the surface of the culture

Fungal mycelium is allowed to grow for 5-14 days for maximum citric acid production

Air is bubbled in to the tank for growth of Aspergillus

SUBMERGED CULTURE Here ,A .niger is cultured

in the liquid medium in small tank fermenters

Air is pumped in to the fermenter from it base to supply enough oxygen for fungal growth

This method produced only a small amount of citric acid

Production of lattic acid :- Lattic acid is another important

organic acid extracted from fermented carbohydrates

It is used in food industries,plastic industry etc

It is prepared by fermenting carbohydrates by certain microbes

The bacteria that produces lactic acid is known as lactic acid bacteria

Eg: lactobacillus bulgaricus lactobacillus pentosus lactobacillus casei lactobacillus lactis

Carbohydrate materials like milk whey,corn starch and potato starch are commonly used as feed stock in the manufacture of of lattic acid

The microbes are then cutured in the fermenters for producing lattic acid

The pH range of 5.5 to 6.5 in the medium favours the growth of lattic acid bacteria

MICROBES IN PRODUCTION OF BIOEHANOL

Ethanol is also known as grain alcohol,spirit etc

It can be used as a fuel for lamps and stoves

Ethanol is prepared from bioresources is called bioethenol

In biotechnology based industries ,ethanol is produced from wastes by the fermentative action of microbes

Any waste rich in carbohydrates can be used as the substrate to produced ethanol

Bioethanol can be prepared from :- grains of maize, corn cane juice etc In the first generation in ethanol

fermentation process corn and other grain are used.it provides nearly 50% of ethanol

Carbohydrates are found locked in wastes

The complex polysaccharides are converted in to simple sugar.It carried out by clostridum thermocellum

The simple sugar are converted in to ethanol by zymomonas mobilis etc

Some microbes produced ethanol directly from carbohydrate wastes

eg: monilia , fusarium

REFERENCE Vyas S.P, Dixit V.K

(2003),Pharmaceutical biotechnology, CBS Publication and distributors

Sullia S.B and shantharam,(2006) ,General microbiology, Oxford and IBH publication

Kumaresan V,(2014) ,Biotechnology,saras publication