Presentation on theme: "Industrial Microorganisms. The laws of applied microbiology (David Perlman, 1980) The microorganism is always right ( your friend, a sensitive partner)."— Presentation transcript:
The laws of applied microbiology (David Perlman, 1980) The microorganism is always right ( your friend, a sensitive partner). There are no stupid microorganisms. Microorganisms can (will) do anything. Microorganisms are smarter (wiser, more energetic) than chemists, engineers, etc. If you take care of your microbial friends, they will take care of your future (and you will live happily ever after).
Microorganisms are useful to provide products & services Ease of mass cultivation Speed of growth Use of cheap substrates (wastes) Diversity of potential products Ability to readily undergo genetic manipulation
Believes of industrial microbiologists The biochemical capabilities of microorganisms are vast. A wide variety of new or unusual substances may be produced by various microbial isolates. Of the 10,000 antibiotically active compounds known in the late 1980's, 67% are produced by microorganisms (67% by actinomycetes, 9% by other bacteria, and 15% by fungi). No door will always be locked. The key is to develop smart procedure and work efficiently. The capacity of an industrial screening group for isolation of microorganisms and thorough testing is around strains per year.
Requisites of an industrial microorganism - 1 Stability: available in pure culture; genetically stable; possible to be maintained for a long period of time; give a predictable amount of desired product in a given fermentation time Cultivation: grow in large-scale; produce many vegetative cells, spores, or other reproductive units; grow vigorously and rapidly in the preparation of inoculum Safety: not be harmful to humans or economically important animals or plants; not produce toxic substances. GRAS (generally regard as safe) microorganisms; crippled strains of GMMs (genetically manipulated microorganisms) or pathogens
Requisites of an industrial microorganism - 2 Economics: grow in inexpensive culture medium obtainable in bulk quantities (wide range of cheap carbon sources, limited or no need for growth factors); produce the required product within a short period of time (preferably in 3 days or less); protect itself against contamination, e.g. lowering the pH, growing at high temperature, rapidly elaborating microbial inhibitor; removed from the culture medium easily; desired product is easily separated from all others (e.g. ready breakage, produce limited byproducts) Modification: amenable to genetic manipulation; capable of genetic recombination; well characterized route of biosynthesis
Examples of microorganisms classified as GRAS (generally regarded as safe) Bacteria: Bacillus subtilis, Lactobacillus bulgaricus, Lactococcus lactis, Leuconostoc oenos Yeasts: Candida utilis, Kluyveromyces marxianus, Kluyveromyces lactis, Saccharomyces cerevisiae Filamentous fungi: Aspergillus niger, Aspergillus oryzae, Mucor javanicus (Mucor circinelloides f. circinelloides), Penicillum roqueforti Normally, these microorganisms require no further testing if used under acceptable cultivation conditions Ref: Waites et. al., 2001
Approaches for obtaining new microbial metabolites Screening: new isolates and/or new test methods. Chemical modification: microbial substances. Biotransformation: microbial or enzymatic reaction. Interspecific protoplast fusion: new or hybrid substances are expected, widely used in the antibiotic industry. Gene cloning: genes of producers of known substances; transfer of genes to nonproducers which contain "silent" genes, leading to the generation of modified or even new substances.
References David Perlman, 1980 Waites, M. J., N. L. Morgan, J. S. Rockey, and G. Higton Industrial Microbiology: An Introduction. Blackwell Science Ltd