1
Conversion of milk into curd
1. Milk is converted into curd or yoghurt by the process of fermentation.
2. In this process the lactose sugar present in the milk is converted into lactic acid by lactic acid bacteria.
3. The acid thus produced by the bacteria curdle the milk.
2
Use of mcrobes in production of alcohol
1. Microbes can be grown in fermentors to make beverages like rum, beer, whisky etc., at industrial scale.
2. Low alcoholic content beverages can be prepared by the fermentation of starch products, while high alcoholic content beverages can be produced by the distillation of fermented malted barley, molasses etc.
3. Depending on the substrate used for fermentation and the type of processing, different alcoholic drinks can be prepared.
4. Saccharomyces cerevisiae is commonly known as ‘brewer’s yeast’ as it produces alcohol by fermentation of different malted cereals and fruit juices.
3
Use of microbes in production of chemicals, enzymes and other bioactive molecules
1. Microorganisms can be used to produce some organic acids. For example, Acetobacter, Clostridium butylicum and Lactobacillus produce acetic acid, butyric acid and lactic acid respectively.
2. The products produced from microbes have medical applications. For example, streptokinase removes clots, statins act as a blood-cholesterol lowering agents, cyclosporin acts as an immuno-suppressant to organ transplant patients.
4
Use of microbes in production of antibiotics
1. Microorganisms produce some special chemicals which have the capacity to kill some other disease-causing microorganisms. These chemicals are termed as antibiotics.
2. Penicillin was the first antibiotic discovered by Alexander Fleming.
3. There are a large number of antibiotics which can be used in curing various diseases such as diphtheria, leprosy, plague etc.
4. Erythromycin, azithromycin, gentamicin are some the examples of antibiotics.
5
Use of microbes in sewage treatment
1. Primary treatment is the first phase of sewage treatment, wastewater is placed in a holding tank and solids settle to the bottom where they are collected and lighter substances like fats and oils are scraped off the top.
2. Secondary treatment is where waste is broken down by aerobic and anaerobic bacteria that are incorporated into the wastewater treatment system through activated sludge digester.
3. Anaerobic bacteria are responsible for methane formation from sewage sludge, facilitating decomposition of macromolecular organic matter into simpler compounds.
6
Use of microbes in production of biogas
1. A biogas plant is an effective way to generate energy from wastes through microbial activity.
2. Biogas generated from biogas plants can be used as low-cost fuel that burns without emitting smoke, for lighting streetlights and to run electric engines.
3. The microorganisms involved in biogas production are methanogens e.g. Methanobacterium.
7
Bacterial biofertilizers
1. Bacteria that improve soil fertility may be symbiotic, non symbiotic (free living) or occurring in loose association with roots of higher plants.
2. They enrich the soil by fixing free nitrogen into nitrogen compounds e.g. ammonia, nitric acid, organic nitrates and thus reduce the dependence on the use of chemical fertilizers.
3. For example, Rhizobium, Azotobacter etc.
Biogas Plant
2
Sewage Treatment Plant
3
Rhizobium – Symbiotic Association
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Mycorrhizae – Biofertilizer
5
Alcoholic Fermentation Plant
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