Microbes in Human Welfare Chapter 8

Study Notes

Microbes are crucial components of biological systems on Earth, present in soil, water, air, and within living organisms.
Microbes include protozoa, bacteria, fungi, microscopic viruses, viroids, and prions, thriving in extreme environments like geysers and deep soil.
Culturing microbes on nutritive media can produce visible colonies that aid in studying microbial characteristics.

Common household uses of microbes include the fermentation of milk into curd by lactic acid bacteria (LAB), enhancing its nutritional value and digestion.
Fermentation processes such as making dough for idli and dosa produce carbon dioxide (CO2), contributing to the dough's texture.
Baker's yeast (Saccharomyces cerevisiae) is employed in bread-making and alcoholic beverages like wine and beer.
Traditional drinks such as 'Toddy' and fermented foods from fish and soybeans also utilize microbial fermentation.
Cheese varieties derive specific flavors and textures from the microbes involved in their fermentation, with examples including Swiss cheese (big holes from CO2) and Roquefort cheese (fungal ripening).

Microbes play a vital role in synthesizing industrial products, including beverages and antibiotics.
Fermentation vessels, known as fermentors, are essential for large-scale microbial growth for industrial applications.
Brewer's yeast is used in the production of various alcoholic beverages through fermentation of cereals and fruit juices.

Sewage treatment plants are established under initiatives like the Ganga Action Plan to reduce river pollution.

Biogas, primarily composed of methane, is produced by microbial activity on organic waste, offering an alternative fuel source.
Methanogenic bacteria, which thrive anaerobically on cellulosic material, including Methanobacterium, generate methane.
Cow dung, rich in methanogens, is commonly used in biogas plants, converting waste into fuel and fertilizer.
Biogas plants consist of a tank for bio-wastes and a slurry of dung, producing gas that can be piped for cooking and lighting purposes.

Biocontrol uses biological methods to manage plant diseases and pests, providing an eco-friendly alternative to harmful chemical pesticides.
The increasing reliance on chemicals in agriculture raises concerns about environmental pollution and health risks to humans and animals.