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.
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
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.)
