Aspergillus niger is the principal industrial fungus used for large-scale production of citric acid by submerged fermentation (using molasses or glucose) because it produces high yields of citric acid under controlled conditions.
Saccharomyces cerevisiae ferments sugars to produce ethanol (and CO2). Acetobacter aceti produces acetic acid, Methanobacterium (methanogens) produce methane, and Penicillium notatum produces the antibiotic penicillin, not acetic acid.
Molasses, a by-product of sugarcane processing, is rich in fermentable sugars and is the common substrate in distilleries for ethanol production using Saccharomyces cerevisiae.
Cyclosporin A is a fungal metabolite used as an immunosuppressive drug. Historically it was obtained from fungi such as Tolypocladium inflatum (and earlier literature refers to related species like Trichoderma polysporum).
In lactate (lactic acid) fermentation pyruvate is reduced to lactate by lactate dehydrogenase without decarboxylation, so CO2 is not released. Alcoholic fermentation involves decarboxylation of pyruvate to acetaldehyde and CO2; aerobic respiration releases CO2 via the TCA cycle.
Biological treatment uses microbes to degrade organic pollutants, thereby reducing Biological Oxygen Demand (BOD) of wastewater before discharge to protect aquatic life.
Anaerobic digestion produces biogas composed mainly of methane (CH4) and carbon dioxide (CO2); hydrogen sulphide (H2S) is also produced by sulfate-reducing bacteria in the sludge.
Process: Pasteurize milk (heat to kill pathogens) then cool to ~40–45°C. Inoculate with starter culture (Lactobacillus and Streptococcus species). These bacteria ferment lactose to lactic acid, lowering pH. Acidification causes casein (milk protein) to reach its isoelectric point and coagulate (precipitate) forming a gel network that traps water and fat — this is curd. Fermentation time/temperature determine texture and taste. Microbial cultures also contribute to flavor by producing small amounts of volatile compounds.
Milk is converted into curd by lactic acid fermentation carried out by lactic acid bacteria (starter cultures) such as Lactobacillus bulgaricus and Streptococcus thermophilus.
1) Penicillin (produced by Penicillium notatum/ Penicillium chrysogenum) — an antibiotic used to treat bacterial infections by inhibiting cell wall synthesis. 2) Cyclosporin A (produced by certain fungi such as Tolypocladium/Trichoderma-related species) — an immunosuppressive drug used to prevent transplant rejection. (Other examples: insulin produced by recombinant Escherichia coli for diabetes; statins like lovastatin from Monascus/Aspergillus used to lower cholesterol.)
1) Penicillin (produced by Penicillium notatum/ Penicillium chrysogenum) — an antibiotic used to treat bacterial infections by inhibiting cell wall synthesis. 2) Cyclosporin A (produced by certain fungi such as Tolypocladium/Trichoderma-related species) — an immunosuppressive drug used to prevent transplant rejection. (Other examples: insulin produced by recombinant Escherichia coli for diabetes; statins like lovastatin from Monascus/Aspergillus used to lower cholesterol.)
a) Antibiotics: Chemical substances, often produced by microorganisms (or synthetically derived), that kill or inhibit the growth of other microorganisms; used to treat bacterial infections. b) Zymology: The branch of science that studies fermentation processes and the organisms and enzymes involved. c) Superbug: A microbial strain (usually bacteria) that is resistant to multiple antibiotics, often due to genetic mutations and horizontal gene transfer, making infections difficult to treat.
a) Antibiotics: Chemical substances, often produced by microorganisms (or synthetically derived), that kill or inhibit the growth of other microorganisms; used to treat bacterial infections. b) Zymology: The branch of science that studies fermentation processes and the organisms and enzymes involved. c) Superbug: A microbial strain (usually bacteria) that is resistant to multiple antibiotics, often due to genetic mutations and horizontal gene transfer, making infections difficult to treat.
a) Brewer's yeast: Saccharomyces cerevisiae used in brewing and baking; ferments sugars to produce ethanol and CO2. In brewing it produces alcohol and flavor compounds; in baking CO2 leavens dough. b) Ideonella sakaiensis: A bacterium discovered to degrade PET plastic using enzymes PETase and MHETase that hydrolyze polyethylene terephthalate into its monomers; potential application in biodegradation and recycling of plastic waste. c) Microbial fuel cells (MFCs): Bioelectrochemical systems in which microorganisms oxidize organic substrates at the anode, releasing electrons that flow through an external circuit to the cathode, generating electricity; used for wastewater treatment with simultaneous energy recovery and biosensing.
a) Brewer's yeast: Saccharomyces cerevisiae used in brewing and baking; ferments sugars to produce ethanol and CO2. In brewing it produces alcohol and flavor compounds; in baking CO2 leavens dough. b) Ideonella sakaiensis: A bacterium discovered to degrade PET plastic using enzymes PETase and MHETase that hydrolyze polyethylene terephthalate into its monomers; potential application in biodegradation and recycling of plastic waste. c) Microbial fuel cells (MFCs): Bioelectrochemical systems in which microorganisms oxidize organic substrates at the anode, releasing electrons that flow through an external circuit to the cathode, generating electricity; used for wastewater treatment with simultaneous energy recovery and biosensing.
Advantages: renewable energy source (biogas: methane) for cooking and lighting; converts animal/plant waste into fuel and reduces environmental pollution; produces nutrient-rich slurry (biofertilizer) for agriculture; reduces reliance on firewood and deforestation; lowers greenhouse gas emissions; improves sanitation by treating waste; provides local energy security and saves money on fuel.
Advantages: renewable energy source (biogas: methane) for cooking and lighting; converts animal/plant waste into fuel and reduces environmental pollution; produces nutrient-rich slurry (biofertilizer) for agriculture; reduces reliance on firewood and deforestation; lowers greenhouse gas emissions; improves sanitation by treating waste; provides local energy security and saves money on fuel.
Antibiotic resistance develops when bacteria are exposed to antibiotics and resistant variants survive and multiply. Causes include overuse and misuse of antibiotics (incomplete courses, unnecessary prescriptions), selection pressure favoring resistant mutants, and horizontal gene transfer (plasmids, transposons) spreading resistance genes. Poor infection control and antibiotic use in agriculture also promote resistance.
Antibiotic resistance develops when bacteria are exposed to antibiotics and resistant variants survive and multiply. Causes include overuse and misuse of antibiotics (incomplete courses, unnecessary prescriptions), selection pressure favoring resistant mutants, and horizontal gene transfer (plasmids, transposons) spreading resistance genes. Poor infection control and antibiotic use in agriculture also promote resistance.
Industrial alcohol refers to ethanol produced for industrial use (fuel, solvents, chemical feedstock). Preparation: feedstock (molasses or starchy materials) is converted to fermentable sugars (saccharification for starch). A sterile mash is inoculated with Saccharomyces cerevisiae which ferments sugars to ethanol and CO2 (fermentation at controlled temperature). Fermented wash is distilled to concentrate ethanol (fractional distillation). Further dehydration (molecular sieves or chemical drying) yields higher-purity industrial ethanol. Process includes monitoring yeast health, sterility, and rectification steps to obtain required purity.
Industrial alcohol refers to ethanol produced for industrial use (fuel, solvents, chemical feedstock). Preparation: feedstock (molasses or starchy materials) is converted to fermentable sugars (saccharification for starch). A sterile mash is inoculated with Saccharomyces cerevisiae which ferments sugars to ethanol and CO2 (fermentation at controlled temperature). Fermented wash is distilled to concentrate ethanol (fractional distillation). Further dehydration (molecular sieves or chemical drying) yields higher-purity industrial ethanol. Process includes monitoring yeast health, sterility, and rectification steps to obtain required purity.
Bioremediation is the use of living organisms, primarily microorganisms and plants, to degrade, detoxify or remove pollutants from the environment. It can be in situ (treating contamination on site) or ex situ (removing contaminated material for treatment). Examples include microbial degradation of oil spills, pesticide breakdown, and use of bacteria to remove heavy metals or plastics.
Bioremediation is the use of living organisms, primarily microorganisms and plants, to degrade, detoxify or remove pollutants from the environment. It can be in situ (treating contamination on site) or ex situ (removing contaminated material for treatment). Examples include microbial degradation of oil spills, pesticide breakdown, and use of bacteria to remove heavy metals or plastics.