The presentation focuses on the method of microbial biotransformation and various reactions involved in the process. It also describes the various applications of microbial biotransformation.

1. MICROBIAL BIOTRANSFORMATION
Dr. A. T. Sharma
Assist. Professor
Nanded Pharmacy College, Nanded

2. Introduction
• Definition: Process which involves microbial
(enzymatic) conversion of a substrate in to a
product with limited number (one or few) of
enzymatic reactions.
• Micro-organisms covert organic compounds in to
structurally related products.
• Fermentation – Large number of reactions
• Maintains the original carbon skeleton in the
products.
• Living cells like bacteria, filamentous fungi,
animals, plants, algae, yeast, actinomycetes are
used

3. Selection of an Organism
• From natural sources or from available
cultures
• Cultures like growing cultures, resting cells,
immobilized cells, spores, enzymes,
immobilized enzymes
Growing cultures:
o A strain is cultivated in an appropriate culture
medium and a concentrated substrate
solution is added after an appropriate growth
(6-24 hours)

4. Advantages:
Usage of large inoculum
Maintaining microbes in growth phase
Use of emulsifiers for dissolution of sparingly
soluble substances
Monitoring of product formation by
spectroscopy/ chromatography
Termination of process after optimum product
formation

5. Resting cells/ Non-growing cells:
o Cells in which division does not occur
o Cells with induced enzymes capable of doing metabolic
reactions, but suspended in non-growth medium and so
can’t make new proteins or cells.
o High cell density due to concentrating large culture volume
in to a small volume – increased productivity and
minimized contamination
Immobilized cells:
o Cells immobilized over a matrix material so that they can be
repeatedly used
Immobilized enzymes:
o Enzymes immobilized by various immobilization
technologies
o Advantages: No cellular transport barriers, Easy and simple
product recovery and isolation

6. Method of Biotransformation
• Micro-organisms are grown in medium for 12-72 hours at
optimum pH, temperature, aeration, agitation in a stainless
steel tank
• After sufficient growth, substrate is added and incubated –
product formation
• Separation of broth from substrate and product
• During incubation, product samples subjected for analysis
at a regular intervals by TLC, paper chromatography, gas
chromatography, or HPLC
• Extraction of product using solvents like methylene
chloride, chloroform, ethyl acetate, methyl isobutyl ketone
• Conversion time depends upon type of reaction, substrate
conversion and microbes involved (few hours to days)
• Proper aeration, agitation and sterility is to be maintained

7. Biotransformation Reactions

9. Applications
Transformation of steroids and sterols:
• Steroids – natural compounds in nature – e.g. bile
salts, adrenocortical and sex hormones,
sapogenins, alkaloids, antibiotics
• All steroids have same basic structure – a
cyclopentanoperhydrophenanthrene – four fused
rings
• Prednisone from cortisone – increased anti-
inflammatory activity
• Production of testosterone and estrogen from
progesterone

10. Transformation of non-steroid compounds:
• Dihydroxyacetone from glycerol – used in lotions and
cosmetics
• Prostaglandins from unsaturated fatty acids –
contraceptives, congenital heart failure etc
• Production of L-ascorbic acid (Vitamin C) –Reichstein-
Grussner synthesis
Transformation of antibiotics:
• Development of new, modified and improved
antibiotics with reduced toxicity, broad antimicrobial
spectrum, enhanced oral absorption, less allergic
effects etc.
Transformation of pesticides:
• Detoxification of environment by enzymatic conversion
and removal of pesticides

11. Transformation of pollutants:
• Microbial transformation of environmental
pollutants like polyaromatic hydrocarbons,
pharmaceutical substances, radionucleotides,
hydrocarbons, polychlorinated biphenyls
Petroleum biotransformation:
• Biodegradation of oil spills by breaking down oil
contaminants in to nontoxic forms
Pharmaceutical research:
• During research activities, comparison of
metabolic pathway of drugs in animal models for
pharmacological and toxicological evaluation.

12. Thank You…!!!
(Disclaimer: The images and diagrams in this presentation
have been downloaded from the google source. I am grateful
to all the publishers & the google.)