Microbes in Human Welfare
Explain the role of lactic acid bacteria (LAB) in the preparation of curd and mention two health benefits associated with it.
How do sewage treatment plants (STPs) help in reducing water pollution? Explain the primary and secondary treatment stages.
Name the source organism of Cyclosporin A and statins. Write one major medical application of each.
Methanogens are anaerobic bacteria that grow on cellulosic material and produce large amounts of methane along with carbon dioxide and hydrogen. These bacteria are collectively known as methanogens, and a common example is Methanobacterium. They play a crucial role in the generation of biogas, which is commonly known as gobar gas. In a biogas plant, the anaerobic digestion of cattle dung and other organic wastes by these bacteria produces a combustible gas mixture rich in methane, which is used for cooking and lighting in rural areas. Naturally in nature, methanogens are found in the rumen of cattle, where they help in the breakdown of cellulose present in the plant-based food eaten by the cattle, and their excreta (dung) is therefore rich in these bacteria, making it an ideal raw material for biogas production.
The yeast Saccharomyces cerevisiae, commonly referred to as brewer's yeast, is of immense commercial importance and has been used for centuries in food processing, specifically in baking and brewing industries. In the baking industry, yeast is added to dough for making bread and other bakery products. During this process, yeast ferments the sugars present in the dough through anaerobic respiration, producing carbon dioxide gas and ethanol. The trapped carbon dioxide bubbles expand and cause the dough to rise, which gives bread its characteristic soft, spongy, and porous texture after baking. In the brewing industry, the same yeast is utilized for fermenting malted cereals and fruit juices to produce various alcoholic beverages such as beer, wine, whisky, brandy, and rum. Depending upon the type of raw material used for fermentation and the type of processing (with or without distillation), different alcoholic drinks are produced on a large commercial scale.
Explain the role of Lactic Acid Bacteria (LAB) in improving the nutritional quality of milk and in human digestion.
Explain how Secondary Treatment (Biological Treatment) of sewage reduces the Biochemical Oxygen Demand (BOD) before wastewater is released into natural water bodies.
Discuss the role of microbes as biocontrol agents, giving two suitable examples of how they help manage plant pests and diseases.
Explain in detail the role of microbes in household food processing and industrial production. Give suitable examples.
Describe the application of microbes in Sewage Treatment Plants (STPs) and as Biofertilizers in detail.