B.Tech (BT) V Sem.
Roll no.- 7274
Deptt. Of Bioscience
Industrial applications of
With ability to grow rapidly
Available in abundant quantities
Must be cheap
Efficient + Economical recovery methods
Several strains of algae, fungi (yeast & molds),
bacteria, protozoa, and viruses.
Genetic Engineering of microorganisms:
Genetic engineering, also known as recombinant
DNA technology, molecular cloning or gene
Recombinant DNA Technology enables
isolation of genes from an organism, this
gene can be amplified, studied, altered &
put into another organism
1. Cutting of donor DNA :
Restriction endonucleases cut DNA
molecule at specific sites and desired
fragment is isolated by gel
2. Cloning of a gene:
DNA fragment, which wanted to be
cloned, is joined to one of vectors
(plasmid, phage, cosmid). For this
purpose, vector and donor DNA are
first cleaved with the same restriction
endonuclease, or with the ones
producing the same ends.
Then using DNA ligase, DNA
fragment and vector DNA is joined. If
fragment has no sticky ends,
homopolymer tailing or linker DNA
segments can be applied for this step.
3. Transformation :
Recombinant vector is put into
suitable host organism, like;
bacteria, yeast, plant or animal cells,
by several physical or chemical
methods. Transformed cells are
identified by several ways:
a. Insertional inactivation (of
antibiotic resistant genes on
b. nucleic acid hybridization
c. labeled Ab's for specific
proteins (immunological test)
are helpful for screening
Factors affecting microbial growth in food
presence and availability of water
altered by cooking
presence of antimicrobial substances
lower temperatures retard microbial growth
higher levels promote microbial growth
oxygen promotes growth
modified atmosphere packaging (MAP)
use of shrink wrap and vacuum technologies to package food
in controlled atmospheres
In field of foods
1. L-lysine Production:
• Essential amino acids –for human nutrition.
• Used as supplement for bread , cereals & other food.
• Two steps for commercial production method:
I. Formation of DAP(diaminopimedic acid) by E.coli .
II. Decarboxylation of DAP by DAP decarboxylase
enzyme from Enterobacter aerogenes .
DAP Lysine + CO2
E.coli – grown in a medium consisting glycerol of corn steep
liquor and (NH4)2HPO4 - under controlled conditions of aeration,
temperature & pH for optimum DAP production.
After several days, Enterobacter aerogenes - added to the mixture -
produces an enzyme DAP decarboxylase that removes the
carboxyl group from DAP to produce lysine
2. L-Glutamic Acid Production:
• Produced by certain species of Micrococcus, Arthrobacter and
• Medium consists of carbohydrates , peptone, inorganic salts & biotin.
• Precursor : -ketoglutaric acid ; enzyme: glutamic dehydrogenase.
• Used in food supplement for human and animals, and its sodium
salt (monosodium glutamate) is utilized in food preparation.
• Used as condiment & flavor-enhancing agent
in form of monosodium glutamate.
This organic compound used in flavoring extracts in soft drinks, foods
& candies; in inks,dyeing, pharmaceuticals (like anticoagulant).
Organism most widely used is the mold: Aspergillus niger
Sterile medium in dispensed into shallow pans – inoculated with
mold pores – under aerobic conditions
Submerged-culture technique: inoculated medium contained in large
tanks through wide supply of air is forced; following affects the yield
of citric acid:
Strain of mold employed
Composition of medium
Degree of aeration
Temperature of incubation
• Food supplements
• Microbes can provide inexpensive source of vitames
i) Riboflavin (vitamin B2)
Produced by Ashbya gossypii(fungi) by fermentation, a mold that
produces 20,000 times the amount it needs for its metabolism.
ii) Cyanocobalamin (Vitamin B12)
• Produced by Pseudomonas, Propionibacterium, Streptomyces grown
in a cobalt-supplement medium.
• This vitamin used in bread, flour, cereal products and animal
iii) Ascorbic Acid (Vitamin C )
• Produced at the rate of 20,000 tonnes per year
• by a complicated modification of glucose by Acetobacter sp.
produced by the mold of Aspergillus oryzae
Used as a spot remover in laundry presoaks, as an adhesive in
Aspergillus oryzae Clostridium spp
produced by Clostridium sp.
used to ret flex for linen and also used in fruit juice.
group of protein digesting enzyme produced by Bacillus subtilis,
Certain proteases are used in leather manufacturing, liquid glues,
laundry presoaks, meat tenderizers, drain openers and spot
produced by yeasts
use in making soft centered chocolate
Produced commercially by fungi; but more recently by genetically
Used to form curds in milk
Is a typical of the miscellaneous microbial products.
Is a sticky substrate used as a thickener in ice cream, soups or
Industrial fermentation –
Large scale cultivation of microbes/single cells – to
produce desired products
Used in anaerobic food fermentations:
o Vinegar production
o Lactic acidproduction
o Brewing & wine making industries
o Dairy products
In biotechnology to obtain useful products from GM
plants & animals
Vessels called as BIOREACTORS – to control:
• Derived from French word
vinagre, meaning sour wine.
• Steps of production:
1. An alcoholic fermentation of
carbohydrate – yeast
2. Oxidation of alcohol to acetic
acid – the acetic acid bacteria ,
species of genus Acetobacter
(inoculated onto the shavings)
• Medium : milk used in “building-up”
• A compound employed to preserve foods,
• Lactic acid is commonly produced by bacterial
activity on the whey portion of milk.
• Microorganism involved in this organic
involves growth of
(baker’s yeast) under
other microbes used to
make special breads
can be spoiled by
Bacillus species that
Milk is feremented by a mixture of Streptococcus salivarius ssp
thermophilus and Lactobacillus bulgaricus Often these two are
co-cultured with other lactic acid bacteria for taste or health
effects (probiotics). These include L. acidophilus, L. casei and
Acid produced from the fermentation causes the protein in
the milk (casein) to coagulate into a semisolid curd
Milk is treated with lactic acid bacteria and an
enzyme called rennin that partially hydrolyses the
protein and causes it to coagulate into “curds.”
The liquid portion of the milk at this time is called
The whey is separated from the curds, and the
curds are aged (“ripened”)
Different microbes in the early and late stages of
processing give rise to cheeses with different