Industrial Micro-organisms

Industrial Micro-organismsOverviewCharacteristics of industrially important microbesTaxonomic groups of industrially important microbesBacteriaGram positiveGram negativeActinomycetes (higher bacteria)FungiFilamentousYeastsIntroduction to primary and secondary metabolismRULES for choice of industrial microbesEconomics rulesCheapest productionSuitable industrial microorganism(a) stable, biochemically and genetically(b) efficient producer of desired product(c) limited/no need additional expensive growth factors(d) utilizes a wide range of carbon sources, cheap plentiful -- preferably waste from another process(e) amenable to genetic manipulation, dispensable extrachromosomal DNA(f) safe, non-pathogen(g) readily removed from fermentation (if the product is extra-cellular) or readily broken open (if the product is intra-cellular)(h) few by-products (ease of purification)(i)physical properties:insensitive to shearlimited foamingnot normally prone to attachment to surfaces etc. Industrially Important MicrobesProkaryotesArchaebacteria (extremeophiles): little importance as yetEubacteria: most industrially important bacteriaActinomyces (filamentous/higher bacteria): secondary metabolitesEukaryotesFungi: numerous products from fungi, often secondary metabolitesYeasts important in brewing, baking amenable to genetic manipulationArchaensLittle current use as industrial microbes exceptLow volume methane production by methanogensLots of potential due to tolerance of conditions detrimental to other microbes, especially high temperatures, salinityEubacteria2 groups comprise almost all industrially important bacteriaProteobacteria: Purple photosynthetic bacteria and non photosynthetic relatives inc E. coli, Nitrobacter, Pseudomonads, Thiobacillus & Vibrio sppGram positive eubacteriaLow GC (Bacillus, Clostridium, Lactobacillus, Staphylococcus)High GC (Streptomyces, Corynebacteria, Mycobacterium)7Clos (No Notes)

Typical gram negative bacterium

E. coliFacultative anaerobe, mixed acid fermentation in anoxic environmentFound human colonFairly complex cell envelope structure, does not stain with Gram stainRapid growth on complex mediaMultiply auxotrophic UV sensitive strains used in recombinant DNA procedures using modified extrachromosomal elements (plasmids)Typical gram positive bacterium

Bacillus subtilisCommon in soil, degrades natural substrates with extracellular enzymes (used industrially esp proteases)Simpler cell envelope structure, stains with Gram stainCan be used for genetic engineeringWhen nutrients become limiting endospores form quiescent, resistant to temperature fluctuations, desiccation, heat, radiationBacillus spp. productsB. thuringiensis: insecticidesB. subtilis: amylase, 5' IMP, recombinant derivative used to produce riboflavinB. licheniformis: subtilisin (biological detergent), bacitracin (peptide antibiotic)B. brevis : gramicidin (peptide antibiotic) B. anthracis: vaccine for anthraxAcetobacter spp. productsA. xylinium: industrial acetic acidA. suboxydans: gluconic acid, ascorbic acidAcetobacter spp: commercial acetification of fermented ethanol derived from wine, beer, cider for vinegar

Lactic acid bacteriaLactobacillus acidophilus, L. casei: fermented probiotic productsL. delbruckii: production of sour mash whiskeyL. delbruckii, L. bulgaricus: manufacture of lactic acidLactococcus lactis: nisin productionActinomycetes

Filamentous bacteria: prokaryotic but fungi-like hyphaeMis-classified as fungi for decadesProkaryotic multicellular organisms with coenocytic organisation equivalent to fungiThe family Streptomyceteae comprises several organisms found in the soil, gives damp soil its characteristic odour Not usually pathogenic

Streptomyces spp.Produce antibiotics clavulanic acid produced by S. clavuligerusstreptomycin by S. griseus, chlortetracycline by S. aureofaciens, oleandomycin by S. antibioticus, spiramycin by S. ambofaciens. erythromycin is produced by Saccharapolyoora erythreaGlucose isomerase produced by S. olivaceous

Fungi

Diverse group of eukaryotes, haploid cellsAmorphous invisible network (mycelium) of thread like hyphae that are frequently coenocyticEnzymes produced that digest extracellular growth substrate, resulting nutrients reabsorbedNuclear membrane persists during mitosisReproduce by spores (asexually and sexually)We are familiar with the spore forming structure

PhycomycetesPrimitive fungiAseptateMucor, Rhizomucor, Rhizopus: used in traditional food fermentations

AscomycetesYeastsFilamentous relativesNeurosporaClavicepsEdible fungiMorchella (morels)Tuber (truffles)

BasidomycetesHaploid spores borne on club like structuresEdible mushroomsAgaricus bisporus (button mushroom)Wood rotting fungi (white rot)Plant pathogens (rusts/smuts)Puff balls

DeuteromycetesResidual classificationUsed where no sexual stage (ascus) has been observedNot discovered yetLost in evolutionIncludes Aspergillus, Cephalosporium, Fusarium, Penicillium, Trichoderma

Aspergillus

A. oryzae: soy sauce fermentations, neutral proteaseA. niger: amylase, aminoglucosidase, citric acidA. itaconicus: itaconic acidA. flavus: soy sauce fermentations wentii: pectinasesA. terreus: lovastatinClaviceps & Trichoderma sppClaviceps spp: ergot alkaloids, lysergic acid, important as drugs

Trichoderma viride: lipases Trichoderma polysporum: cyclosporin (immunosuppresant/antibiotic)Yeasts

Unicellular fungusReproduce asexually by budding (Sacchromyces) or binary fission (Schizosaccharomyces)Unlike most other fungi can grow anaerobically producing alcohol and CO2 from sugarsBrewingBaking breadLike bacteria can grow on fairly simple media, but more slowly (doubling time 3-4 hrs)Like bacteria can be easily genetically manipulatedUsed to study eukaryotic cell cycleYeastSacchromyces cerevisiae: brewing, baking, industrial/fuel ethanol, single cell protein

Kluyveromyces spp: invertaseK. lactis: -galactosidase (lactase)

Primary metabolitesIndispensable for growthPyruvateGlyceraldehyde 3 phosphateSuccinateRiboflavinGlycineThymineUrea

Etc, etc.

Secondary metabolitesA compound that is not necessary for growth or maintenance of cellular functions but is synthesized, generally, for the protection of a cell or micro-organism, during the stationary phase of the growth cycle.

Secondary metabolites (natural products) are those products of metabolism that are not essential for normal growth, development or reproduction of an organism. In this sense they are secondary.

Industrial primary metabolitesPrimary Organism SignificanceMetaboliteEthanol Saccharomyces cerevisiae alcoholic beverages Kluyveromyces fragilisCitric acid Aspergillus nigerfood industryAcetone and Clostridium acetobutyricum solventsbutanolLysine Corynebacterium glutamacium nutritional additiveGlutamic acid flavour enhancerRiboflavin Ashbya gossipii nutritional Eremothecium ashbyiVitamin B12 Pseudomonas denitrificans nutritional Propionibacterium shermaniiDextran Leuconostoc mesenteroides industrialXanthan gum Xanthomonas campestris industrialSecondary metabolitesMetaboliteSpeciesSignificancePenicillinPenicillium chrysogenum antibioticErythromycinStreptomyces erythreusantibioticStreptomycin Streptomyces griseusantibioticCephalosporinCephalosp. acremoniumantibioticGriseofulvinPenicillium griseofulvin antifungalCyclosporin ATolypocladium inflatum immuno-suppressantGibberellinGibberella fujikuroiplant growthfactorSummaryIndustrial microbes Encompass a wide variety of taxons, but many taxons lack a useful microbePrincipally bacteria and fungiGrow rapidly on inexpensive substratesWide variety enable production of a wide range of useful primary and secondary metabolitesMany can be genetically manipulated