Transcript Polytechnic of Namibia

Polytechnic of Namibia
Industrial Microbiology
Introduction to
Industrial Microbiology
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Lecturer M.Zivuku
Polytechnic of Namibia
Objectives
By the end of this unit, you must be able to
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Define the following term industrial microbiology,
primary metabolite and secondary metabolite
List examples of primary metabolites and secondary
metabolites
Describe and explain the main uses of microorganisms
in the production of antibiotics, dairy products, single
cell proteins, organic solvents, amino acids.
Discuss the use of microorganism in agriculture,
mineral extraction and genetic engineering
 Site some good examples of application of
Bioremediation in nature
Lecturer M.Zivuku
Polytechnic of Namibia
Industrial Microbiology
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History of industrial Microbiology
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A. 1st phase : traditional industrial microbiology
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milk, vegetables
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bread, beer, wine, distilled spirits, vinegar
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cheese, pickles, other fermented materials
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solvents, organic acids, vitamins, enzymes and other products.
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antibiotic fermentations (penicillin, streptomycin)
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mutational microbial genetics
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B. 2nd phase : modern industrial fermentations
C. 3rd phase : modern biotechnology
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health care, diagnostics, agriculture, productions of chemicals,
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petroleum, mining, foods, environment bioremedation
Lecturer M.Zivuku
Polytechnic of Namibia
Industrial Microbes and their
Products
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Industrial Microbiology
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Uses microorganisms, typically grown on a large scale, to
produce products or carry out chemical transformation
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Originated with alcoholic fermentation processes
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Later on, processes such as production of pharmaceuticals,
food additives, enzymes, and chemicals were developed
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Major organisms used are fungi and Streptomyces
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Classic methods are used to select for high-yielding microbial
variants
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Lecturer M.Zivuku
Polytechnic of Namibia
Industrial Microorganisms and their
Produts
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Properties of a useful industrial microbe include
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Produces spores or can be easily inoculated
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Grows rapidly on a large scale in inexpensive medium
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Produces desired product quickly
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Should not be pathogenic
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Amenable to genetic manipulation
Lecturer M.Zivuku
Polytechnic of Namibia
Primary and Secondary Metabolites
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Primary Metabolite
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Produced during exponential growth
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e.g., alcohol
Secondary Metabolite
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Produced during stationary phase
Lecturer M.Zivuku
Polytechnic of Namibia
Examples of Primary and Secondary
Metabolites
Primary Metabolites
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Primary metabolites
- Amino acids
- Vitamins
- Nucleotide
Guanylic acid
(GMP),
Inosinic acid
(IMP)
- Organic acids
Citric acid
- Enzymes
Lecturer M.Zivuku
Secondary Metabolites
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Secondary metabolites
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- Antibiotics
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- Other medicinal active
substances
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- Toxins
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- Pesticides
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- Animal and plant growth
factors
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- Sex hormones
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- effectors of differentiation
Polytechnic of Namibia
Primary Metabolite Production
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Lecturer M.Zivuku
Polytechnic of Namibia
Secondary Metabolite Production
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Lecturer M.Zivuku
Polytechnic of Namibia
Products for Health Care Industry
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9.1 Antibiotics: Isolation and Characterization
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9.2 Industrial Production of Penicillins and
Tetracyclines
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9.3 Vitamins and Amino Acids
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9.4 Steroids and Other Biotransformations
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9.5 Enzymes as Industrial Products
Lecturer M.Zivuku
Polytechnic of Namibia
Production of Antibiotics
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About 100 antibiotics manufactured in large quantities since first
production of penicillin in 1940s. Improve yields by using mutated
strains and improving fermentation
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procedures e.g. strain that once produced 60 mg of penicillin per
litre of culture now makes 20 g/l.
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Many antibiotics now are semi-synthetic i.e. made partly by
microbes and modified by chemists.
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Made by fungi and bacteria (esp. Streptomyces spp.)
Lecturer M.Zivuku
Polytechnic of Namibia
Antibiotics: Isolation and
characterisation
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Antibiotics
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Compounds that kill or inhibit the growth of other microbes
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Typically secondary metabolites
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Most antibiotics in clinical use are produced by filamentous
fungi or actinomycetes
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Still discovered by a laboratory screening process
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Microbes are obtained from nature in pure culture
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Assayed for products that inhibit growth of test bacteria
Lecturer M.Zivuku
Polytechnic of Namibia
Mode of Action of Some Major
Antimicrobial Agents
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Lecturer M.Zivuku
Polytechnic of Namibia
Isolation and Screening of
Antibiotic Producers
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Lecturer M.Zivuku
Polytechnic of Namibia
Isolation and Screening of
Antibiotic Producers
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Lecturer M.Zivuku
Polytechnic of Namibia
Antibiotics: Isolation and
Characterization
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Cross-Streak Method
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Used to test new microbial isolates for antibiotic production
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Most isolates produce known antibiotics
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Most antibiotics fail toxicity and therapeutic tests in animals
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Time and cost of developing a new antibiotic is approximately
15 years and 1 billion dollars
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Involves clinical trials and U.S. FDA approval
Antibiotic purification and extraction often involves elaborate
methods
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Lecturer M.Zivuku
Polytechnic of Namibia
Bacteria as Food Source
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Known as single-cell protein; being investigated as solution to world
food problem.
Bacteria being investigated because a huge variety of substances
including industrial waste products can be used by bacteria as
substrate for biomass production.
Examples of bacteria used as food:
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Cyanobacteria, Spirulina grown in alkaline lakes in Africa, Mexico
and by Incas in Peru. Dried-made into cakes!
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Pruteen, Methylophilus methylotrophus grown on methanol, and
proposed as animal feed. 70% protein. Problems with commercial
viability due to subsidisation of alternative animal feeds.
Lecturer M.Zivuku
Polytechnic of Namibia
Bacteria in Food Production: Dairy
Products
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Rely on production of lactic acid or alcohol as well as other
variable by-products of fermentation e.g.
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Streptococcus and Leuconostoc spp. used to make buttermilk
and sour cream with different flavors by adding bacteria to
pasteurised skim milk or cream respectively.
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Yoghurt made by adding Streptococcus thermophilus and
Lactobacillus bulgaricus to milk.
Lecturer M.Zivuku
Polytechnic of Namibia
Dairy Products
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Cheese made by adding lactic acid bacteria and either rennin
or bacterial enzymes to milk. The bacteria sour the milk and
the enzymes coagulate the milk protein casein. The liquid
whey is removed to varying degrees, depending on the
hardness of the cheese, and the solid curd is usually ripened
by a mixture of bacteria. These produce lactic and other
acids, alcohols, proteolytic enzymes and lipases, which
flavour and soften the cheese
Lecturer M.Zivuku
Polytechnic of Namibia
Bacteria in Food Production:
Other Fermentations
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Vinegar: made e.g. by fermenting apple juice or grape juice
to produce ethanol. Then, Acetobacter aceti oxidise ethanol
to acetic acid.
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Sauerkraut: packed shredded cabbage in 2-3% salt fermented
by anaerobic halophilic species of Lactobacillus and
Leuconostoc. Bacteria produce lactic acid, acetic acid,
carbon dioxide, alcohol and other substances.
Lecturer M.Zivuku
Polytechnic of Namibia
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Pickles: cucumbers in brine fermented by Leuconostoc or
Pediococcus spp. Later add vinegar, spices and sometimes
sugar, and usually pasteurise.
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Olives: Leuconostoc and Lactobacillus
Lecturer M.Zivuku
Polytechnic of Namibia
Organic Solvent Production
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Microbes can produce hundreds of different chemicals, but
many manufactured more economically by chemical
synthesis. This may change as oil prices rise, especially if
the microbes are genetically engineered to increase output.
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Microbes used in part of production of ethanol, acetone and
butanol e.g. thermophilic clostridia and Zymomonas being
used in alcohol production.
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Clostridium acetobutylicum produces butanol and acetone
when grown on starch. (Butanol used in making brake fluid,
resins and petrol additives; acetone used as solvent).
Lecturer M.Zivuku
Polytechnic of Namibia
Production of Organic Acids
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Acetic acid made by several species e.g. thermophiles can
make it from cellulose and others can make it from hydrogen
and carbon dioxide. Used in manufacture of rubber, plastics,
fabrics, insecticides, photographic materials, dyes and
pharmaceuticals. Also made by Acetobacter from ethanol in
food industry.
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Lactic acid made by Lactobacillus delbrueckii from glucose
and used in foods, textiles, plastics and electroplating
Lecturer M.Zivuku
Polytechnic of Namibia
Amino Acid Supplements
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Of the 20 amino acids in proteins, 8 cannot be synthesised
by most animals and must therefore be obtained in the diet
(i.e. essential amino acids). Lysine and methionine are
present in only small amounts in grains, and are therefore
added to animal feed, and sold as supplements for human
consumption. Methionine made synthetically but…….
Lecturer M.Zivuku
Polytechnic of Namibia
Amino acids supplements
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Lysine made by an overproducing mutant strain of
Corynebacterium glutamicum which lacks feedback
inhibition.
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Glutamic acid used as food flavouring - monosodium
glutamate. Made by C. glutamicum mutant which makes
high yields of glutamic acid (as offshoot of TCA cycle) and
which can excrete the amino acid from the cell when grown
in media which results in a leaky cytoplasmic membrane.
Lecturer M.Zivuku
Polytechnic of Namibia
Other Products
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Polysaccharides e.g.
xantham gum produced from Xanthomonas
campestris and used in foods for its pseudoplasticity
property;
dextran made by Leuconostoc spp.used in medicine.
Vitamins e.g.
vitamin B12 and
riboflavin
Lecturer M.Zivuku
Polytechnic of Namibia
Bacteria in Agriculture
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Pest Control
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Bacillus thuringiensis; Photorhabdus and Xenorhabdus spp.
and their nematode symbionts used to kill insect pests.
Organism may be applied directly or insecticidal toxin gene
may be engineered into the plant.
Lecturer M.Zivuku
Polytechnic of Namibia
Recombinants DNA Technology
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Human genes cloned into E. coli and yeast to produce
insulin, growth hormone, interferons.
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Vaccines made by cloning genes coding for antigenic surface
proteins from pathogens into E. coli and yeast.
Lecturer M.Zivuku
Polytechnic of Namibia
Recombinant DNA Technology
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Plants can be genetically engineered with useful genes
placed on the Ti plasmid of Agrobacterium tumefaciens,
which integrates part of its DNA into the chromosome of
infected plants. The plasmid is engineered so that it can no
longer cause the crown gall disease tumors. Genes
engineered into plants include those for herbicide resistance,
pest resistance, shelf life etc.
Pseudomonas syringae -ice-minus bacteria - recombinant
strains can’t make proteins which act as nuclei for ice crystal
formation. Use to colonise surface of plants to replace
normal bacterial flora. Allows plants to survive brief
freezing at -3oC
Lecturer M.Zivuku
Polytechnic of Namibia
Microbial Mining
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Microbes can be used to extract minerals from less
concentrated ores.
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Copper, zinc, iron, lead and uranium found as sulphide
minerals.
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Thiobacillus ferrooxidans is a chemoautotroph which
oxidises the sulphur in copper or iron sulphide with a
resultant release of pure copper or iron. This process is even
more rapid in presence of T. thiooxidans as well.
Lecturer M.Zivuku
Polytechnic of Namibia
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Bioremediation - the use of microbes to detoxify chemical
wastes. Examples:
Arochlor 1260 is one of the most toxic of the
polychlorinated biphenyl compounds, and three strains of
microbes have been found which deactivate it.
Other organisms have been found to detoxify cyanide and
dioxin and to degrade oil spills. A genetically modified
bacterium can degrade Agent Orange.
Research ongoing on microorganisms found in waste dumps,
but little genetic characterisation as yet, so genetic
modification limited so far.
Lecturer M.Zivuku
Polytechnic of Namibia
END
THANK
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Lecturer M.Zivuku
YOU !!!