•         Use of microorganisms grown on large scale for production of valuable commercial products/ to carry out important chemical transformations

•         originated with alcoholic fermentation processes-wine, beer

•         developed for pharmaceutical agents (antibiotics), food additives (amino acids), enzymes, chemicals - butanol, citric acids.

•         New era- microbial biotechnology - manipulation of genes give new microbial products most not naturally produced by microbes

•         biocatalysts - use of microorganisms as microbial catalysts for specific chemical reaction

Industrial Microorganisms and Products

•         Major organisms use in biocatalytic processes- fungi (yeasts & mould) ; certain procaryotes - members of Streptomyces

•         strains for industrial use of high metabolic specialization achieved - genetically altered via mutation/recombinant DNA hybridisation focussing on yield of particular product

•         once strains developed then conserved by microbiological lab. Indusrty & in national culture collection - normally low yield strain deposited

Desirable Properties of useful industrial microorganisms:

•         Produce substance of interest

•         rapid growth and form product at short period

•         genetically stable

•         capable of growth at industrial scale & on inexpensive medium

•         not harmful to human or economically important plants and animals

•         produce spores/other reproductive structure for ease of inoculation

•         easily manipulated genetically - mutation , selection

Examples of Industrial Products

            Growth and Product Formation in Biocatalyses - when in the growth cycle is the industrially useful metabolite produced?

•         Two basic types of microbial metabolites:

1.      Primary - formed during exponential phase, cells and metabolite produced simultaneously eg alcohol(anaerobic metabolism of yeast & certain bacteria, as part of energy metabolism)

2.      Secondary - at or near stationary phase, after cells produced, further growth primary metabolite convert to secondary eg antibiotic

Characteristics of Secondary Metabolites

•         Each only formed by relatively few organisms

•         Not essential for growth and reproduction

•         Formation dependent on growth conditions especially composition of media, repression of formation can occur frequently

•         Often produced as group of closely related structures eg, spp. of Streptomyces produce > 30 related but different anthracycline

•         Can often get dramatic overproduction compared to primary metabolites

•         Product can be derived from primary metabolite not necessarily the primary substrate itself, therefore can get secondary metabolites from several intermediate products accumulating either in culture medium or cells during primary growth.

Antibiotics(substances produced by microorganisms that kill or inhibit growth of other microorganisms):

Isolation and Characterization:

•         Produced by filamentous fungi and actinomycetes.(Streptomyces, Penicillins, Bacillus)

•         Antibiotics classsified according to their chemical structure

•         >8000 known antibiotic substances, several hundreds discovered yearly, more to be discovered

•         Screening traditional means, however genetic engineering technique will permit artificially design new antibiotic -- eventually replace traditional screening method??

•         Reality ? Currently computer model interaction between a drug’s target and modified version of a known drug, computer screen hypothetical drugs and predict  their efficacy, identified drug can be synthesised by  chemical or biological modification of existing drug, then tested for clinical effectiveness

Isolation and Screening of Antibiotic Producers Using Traditional Means

Other Microbial Products:

•         Vitamins and Amino Acids

•         Microbial bioconversion

•         Enzymes

•         Vinegar

•         Citric Acid and Other Organic Compounds

•         Industrial Use of Yeast-production of yeast cells, yeast products, fermentation products, beverage alcohol and distilled beverage