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25 Cards in this Set
- Front
- Back
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The industrial uses of microbes |
Foodstuffs Manufacture food and drink Pharmaceuticals Biocontrol Bioremediation Sewage treatment |
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Microorganisms used as or in food |
Meat substitute, Fusarium venenatun - grown in oxygenated water in sterile fermentation tanks, dried and mixed with albumin. FIlaments of fungus texturised to give meat texture Homogensised saccaromyces cerevisiae - byproduct of beer industry Probiotics - live microorganisms used in yoghurt for health benefits |
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Define fermentation |
Conversion of carbohydrates into alcohols or acids |
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Products produced by fermentation |
Wine, beer, spirits, lager Soybean products Sauerkraut Grass silage Olives Coffee |
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Other products produced by fermentation |
Bread making - S.cerevisae, fermentation produces CO2 which gives bubbly texture and ethanol which evaporates. Other fermentation products give flavour Cheese - lactic acid fermentation of milk by lactococcus lactis which coagulates milk proteins to produce curd. Other bacteria e.g. penicillum added for flavour |
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Natural products from bacteria |
Antibiotics, amino acids, organic acids, bipolymers, |
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Production of antibiotics |
Natural products of microorganisms Governed by environmental conditions Produced as a byproduct of secondary metabolism - where microorganism alter metabolism when placed under stressful conditions to eliminate competition or promote survival |
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THE FOOD INDUSTRY Amino acid production |
Glutamic acid and lysine used for nutritional supplements and MSG as flavour enhancer. Produced by bacteria (regulatory mutants), those that have lost ability to regulate physiology properly will produce amino acids in large quantities as they lack ability to control build up of metabolites |
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Organic acid production |
Citric, acetic, lactic, fumeric and gluconic acids used by industry. Much cheaper to produce by bacteria Achieved by manipulating amount of trace metals in culture media, used as enzyme cofactors to make bacteria produce lots of organic acid |
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Production of citric acid |
Aspergillus niger (fungus) Reducing manganese and iron to stop growth at a particular point which results in lots of citric acid being produced |
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Production of biopolymers |
Usually polysaccharides, used in food industry to modify texture (sauces etc) Used as gelling agents in pharmaceuticals Paints absorbants, plastics, food thickeners, lubricants and asphalt Xantham gum - exopolysaccharide produced by Xanthamonas campestris during fermention of glucose or sucrose. Used to increase viscosity. |
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Biocontrol |
Use of bacteria (fungi or viruses) or their products as bioinsecticides Bacillus thuringiensis - rod, weakly toxic to insects. Produces intracellular protein toxin crystal upon sporulation which is active against insects |
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Toxin from Bacillus thuringiensis |
Ingested by insects and goes into gut. Alkaline conditions in gut cause it to fragment releasing protoxin. This reacts with protease to produce active toxin which integrates into plasma membrane causing cell lysis. It breaks down naturally in environment by abiotic degradation |
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Insertion of Bt toxin into plants |
Gene for Bt toxin, cry, cloned into plants so plants produce their own toxin. When insects eat the plant they therefore die. Commercialised Bt-corn, potato and cotton produced |
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Recombinant products |
Genes from one organism inserted into a different organism e.g. insulin gene can be inserted into E.coli so it produces human gene |
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Why use recombinant insulin? |
Ethical reasons not to use animal insulin Animal proteins are different from humans e.g. bovine insulin has 3 amino acid differences Not to contaminated with infectious agents e.g. mad cow disease Engineer new types of insulin to modify characteristics by altering amino acid sequence |
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How is the insulin inserted into E.coli? |
Human gene inserted into high copy number plasmid (small genetic part, circular) The plasmid is inserted into E.coli Human insulin then produced from E.coli |
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Bioremediation |
Use of bacteria, fungi or their enzymes to return an environment altered by contamination to original state |
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Biostimulation |
Nutrientsand oxygen are added to contaminated water or soil to encourage the growth andactivity of bacteria already existing in the soil or water. The disappearanceof contaminants is monitored to ensure that remediation occurs. |
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Bioaugmentation |
Microorganismsthat can clean up a particular contaminant are added to the contaminated soilor water. Used on contamination removed from original site. |
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Intrinsic bioremediation |
Occursnaturally in contaminated soil or water. This natural bioremediation is thework of microorganisms and is seen in petroleum contamination sites, such asold gas stations with leaky underground oil tanks. |
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Benefits of bioremediation |
Cost effective Capitalises on natural processes Treat widely dispersed contaminants across large area Minimizes environmental disturbance Rapidly mineralise contaminants and eliminate need for disposal. |
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Limitations of bioremediation |
Failures are common as limited process, likely that microbes cannot adapt to survive in new environment Lack of nutrients Competition Immobility of introduced microorganism Contaminant concentration too low Organisms use other substrate |
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Considerations taken into place for bioremediaton |
Site specificity - each environment has a new set of conditions which cannot be controlled Ethical considerations - objections to adding foreign species or GM organisms |
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Use of microorganisms for sewage treatment |
Microorganisms metabolise solid waste by oxidising nutrients to produce energy and chemicals (e.g. phosphates, nitrates and sulphates) |
