Biology - Microbes in Human Welfare

This lecture introduces microbes and micro-organisms, their ubiquity in soil, water, and living beings, and their study in microbiology, contrasting harmful pathogens with useful microbes in health and food applications.

Explore microbial fermentation, where Lactobacillus, Leuconostoc, Streptococcus, Saccharomyces, and Candida break glucose without oxygen to produce carbon dioxide and alcohol, making dough fluffy and flavors richer.

Grow single cell protein from bacteria, fungi, and algae in nutrient media, then dry for use as a protein-rich food source, and examine edible and poisonous mushrooms.

Fermentation of milk by lactic acid bacteria converts lactose into lactic acid, producing yogurt, cheese, and buttermilk, with Lactobacillus and Streptococcus thermophilus coagulating proteins and adding flavor.

Explore how Saccharomyces cerevisiae drives fermentation to produce ethyl alcohol. It covers wine, beer, and whiskey, plus regional drinks such as toddy and cashew feni.

Milk undergoes biochemical and microbiological tests and pasteurization, then coagulates with Lactobacillus lactis, Lactobacillus creameries, and Streptococcus thermophilus to form lactic acid, producing cheeses like Camembert, Roquefort, and Swiss.

Explore how microbes produce vitamins B2, B12, and C, distinguish fat-soluble from water-soluble vitamins, and examine dietary sources and deficiency symptoms like night blindness, scurvy, sterility, and rickets.

Explore how microbes produce enzymes that act as biocatalysts to speed reactions in alcohol, bakery, dairy, cheese, fruit juice clarification, and detergents.

Explore how microbes produce antibiotics that kill or inhibit disease-causing microbes, tracing penicillin's 1929 discovery by Fleming to their therapeutic importance and examples like penicillin, streptomycin, and erythromycin.

Learn how sewage treatment removes microbes and organic matter from domestic and industrial wastewater through primary, secondary, and tertiary steps in treatment plants before releasing clean water into water bodies.

Learn how microbes drive sewage treatment in three stages: primary filtration and sedimentation remove debris, secondary aeration forms flocs that reduce organic matter, and anaerobic digestion clears remaining filaments.

Discover how Gibberella fujikuroi–produced gibberellins promote stem elongation and break seed dormancy. These hormones also induce flowering under short days and enhance fruit size, including seedless varieties.

Biogas production uses anaerobic microbes to convert plant and animal waste into methane-rich gas in a digester with a floating dome, providing clean, renewable fuel for cooking and lighting.

Explore how plant and animal waste undergo anaerobic digestion, converting polymers to monomers, then to organic acids and finally methane, the key biogas component, via microbes like Pseudomonas and Clostridium.

Bio herbicides use fungal and bacterial agents to selectively kill weeds in monocrop fields, reducing hogs and grasses without harming crops or soil fertility, unlike chemical herbicides.

Fix atmospheric nitrogen in paddy fields using heterocysts, as cyanobacteria, or blue-green algae, act as biofertilizers. Form symbiotic relationships with azolla to enhance rice cultivation.

Biofertilizers like Rhizobium fix atmospheric nitrogen in legume root nodules, boosting soil nitrogen and crop yield while offering a sustainable alternative to chemical fertilizers.

explore biofertilizers through mycorrhiza, a fungal symbiosis with vascular plant roots that boosts water and mineral uptake via ecto and endomycorrhizal forms.