microorganisms as research tools_presentation

8/13/2019 Microorganisms as Research Tools_Presentation

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Microorganisms as research tools


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Introduction Microorganisms are minute living things that are individually too

small to be seen with the naked eye. They can only be seen with thehelp of microscope.They include bacteria, fungi, protists, microscopic plants (greenalgae); and animals (plankton and the planarian). Some

microbiologists also include viruses.

Microbiology is the study of microbes. It is divided into two majorfields: theoretical and applied.In applied microbiology, industrial and pharmaceutical microbiologyare the most promising areas.


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Microorganisms in genetic engineering Genetic engineering is the manipulation of genes.

Also called recombinant DNA technology.

Plasmid method, is the most familiar technique in geneticengineering in which pieces of DNA (genes) are introduced into a

host by means of a carrier (vector) system.Vector - Plasmid (circular bacterial DNA)

Human insulin (used against diabetes), and human growth hormone(used to treat pituitary dwarfism) are the two products commerciallyproduced by this method.E. coli bacterium is used in the production of human insulin.


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Antibiotics Antibiotics are biochemicals secreted by microorganisms

which, in low concentration, inhibit the growth or kill otherdisease causing microorganisms.

Out of 6000 known antibiotics, 3000 are obtained from just sixgenera of filamentous fungi and about 2,000 from threegenera of bacteria.


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Antibiotics of Fungal Origin

Antibiotic(Product)

Microbialsource

Mode ofaction

Primaryspectrum

Ampicillin (apenicillinderivative

Penicillium sp. Inhabits cell-wall synthesis

Gram (+) Gram(-) bacteria

Methichillin Penicillium sp. Inhibits cell Staphylococci

Cephalosporin Cephalosporiumsp.

Inhabits cell-wall synthesis

Gram (+)bacteria


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Antibiotics of Bacterial Origin

Antibiotic(Product)

Microbialsource

Mode of action Primary spectrum

Nystatin S. rimosus Interferes with

protein synthesis

Intestinal Candida,

other fungi

Bacitracin Bacillussubtilis

Inhibits cell wallsynthesis

Gram-positivebacteria


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Vitamin Production Riboflavin (vitamin B 2) is recovered as a by-product of acetone

butanol fermentation however using the yeasts, Eremotheciumashbyii and Ashnua gossypii this vitamin can be producedcomercially on a large scale by microbial fermentation

Vitamin B12 (Cyanocobalamine; Cobalbumin) is recovered as a by-product of streptomycin and aureomycin antibiotic fermentations. Bymicrobial fermentation using the bacteria, Propionibacteriumshermanii or Pseudomonas denitrificans, the vitamin can beproduced on a large-scale.


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Biotransformation of Steroids Steroids are complex chemical substances containing tetracyclic

carbon ring.Steroid hormones regulate various metabolic aspects in man.Microfungi and bacteria has become very important in theirproduction (biotransformation) in pharmaceutical industry.

Cortisone is a steroid hormone used to relieve the pain associatedwith rheumatic arthritis in humans.Chemically synthesized from deoxychloric acid. It completes in 37different steps, requiring extreme conditions of temperature andpressure for completion and resulting in a very expensive product.


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The difficult aspect is the introduction of an oxygen atom at thenumber 11 position of the steroid ring of progesterone, an

intermediate. If progesterone is added to a fermentation tank containing Rhizopus

nigricans growing for approximately a day, the progesterone ishydroxylated at the number 11 position of its steroid ring to form a11-hydroxyprogesterone.The product is recovered by extraction with methylene chloride orvarious other solvents, purified, and recovered by crystallization.11-a-hydroxyprogesterone is then subjected to chemical synthesissteps and, finally, cortisone is obtained. The process is easy and haslowered the original cost 400-fold.


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A vaccine is a biological preparation that improves immunity to aparticular disease. It typically contains an agent that resembles adisease-causing microorganism, and is often made from weakenedor killed forms of the microbe or its toxins. The agent stimulates thebody's immune system to recognize the agent as foreign, destroy it,and "remember" it, so that the immune system can more easilyrecognize and destroy any of these microorganisms that it laterencounters.Four basic types of vaccine are:-Inactivated vaccines-Live, Attenuated Vaccines

-Subunit Vaccines-Recombinant Vector Vaccines

Vaccine


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Bacterial and Viral Vaccines in Current Use

Baterial disease Vaccine Composition

Cholera Crude fraction of Vibrio cholera

Tuberculosis Attenuated Mycobacteriumtuberculosis

Haemophilus Meningitis Purified polysaccharide from

Haemophilus influenze type b


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Viral disease Vaccine Composition

Hepatitis B Subunit Vaccine

Measles Attenuated Virus


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Microbial enzymes are most widely used in the food and beverageindustries and as protease detergents in washing powders.The most economical and convenient method of producing theseenzymes is by microbial fermentation.

Microbial enzyme


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Some important microbial enzymes and theirapplications

Source(genus)

Enzymes Reaction Application

Bacillus -Amylase

Proteases

Starch hydrolysis

Protein digestion

Converts starch to

glucose in foodindustry

Help laundering

Streptomyces Glucoseisomerase

Conversion ofglucose offructose

Production of highfructose syrups

microorganisms as research tools_presentation

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