chapter 8 microbes in human welfare

Microbes — Microscopic organisms including bacteria, fungi, protozoa and viruses

Ubiquity of microbes — Found in soil, water, air and inside living organisms :contentReference[oaicite:1]{index=1}

Microbes in household products — Used in food preparation and fermentation

Lactic Acid Bacteria (LAB) — Converts milk into curd and improves vitamin B12 content :contentReference[oaicite:2]{index=2}

Role of LAB in stomach — Prevents growth of harmful microbes :contentReference[oaicite:3]{index=3}

Fermentation in dough — Produces CO₂ causing dough to rise :contentReference[oaicite:4]{index=4}

Baker’s yeast — Saccharomyces cerevisiae used in bread making :contentReference[oaicite:5]{index=5}

Cheese production — Uses microbes like Penicillium and Propionibacterium :contentReference[oaicite:6]{index=6}

Microbes in industrial production — Used for large-scale production of useful products

Fermentors — Large vessels used to grow microbes industrially :contentReference[oaicite:7]{index=7}

Fermented beverages — Produced using yeast fermentation

Antibiotics — Chemicals produced by microbes that kill pathogens :contentReference[oaicite:8]{index=8}

Penicillin — First antibiotic discovered by Alexander Fleming :contentReference[oaicite:9]{index=9}

Citric acid production — Produced by Aspergillus niger :contentReference[oaicite:10]{index=10}

Acetic acid production — Produced by Acetobacter aceti :contentReference[oaicite:11]{index=11}

Lactic acid production — Produced by Lactobacillus :contentReference[oaicite:12]{index=12}

Enzymes from microbes — Used in detergents and juice clarification :contentReference[oaicite:13]{index=13}

Streptokinase — Clot buster enzyme used in heart patients :contentReference[oaicite:14]{index=14}

Cyclosporin A — Immunosuppressive drug from fungi :contentReference[oaicite:15]{index=15}

Statins — Lower blood cholesterol levels :contentReference[oaicite:16]{index=16}

Microbes in sewage treatment — Used to clean wastewater

Primary treatment — Physical removal of particles :contentReference[oaicite:17]{index=17}

Secondary treatment — Microbial degradation of organic matter :contentReference[oaicite:18]{index=18}

Flocs — Clusters of bacteria and fungal filaments :contentReference[oaicite:19]{index=19}

BOD (Biochemical Oxygen Demand) — Measure of organic pollution in water :contentReference[oaicite:20]{index=20}

Methanogens — Produce methane during anaerobic digestion :contentReference[oaicite:21]{index=21}

Biogas — Mixture of gases mainly methane produced from organic waste :contentReference[oaicite:22]{index=22}

Microbes in biogas plant — Methanobacterium plays key role :contentReference[oaicite:23]{index=23}

Biocontrol — Use of microbes to control pests and diseases :contentReference[oaicite:24]{index=24}

Bacillus thuringiensis (Bt) — Controls insect pests :contentReference[oaicite:25]{index=25}

Trichoderma — Controls plant pathogens :contentReference[oaicite:26]{index=26}

Baculoviruses — Used in pest control with high specificity :contentReference[oaicite:27]{index=27}

Biofertilizers — Microbes that enrich soil nutrients :contentReference[oaicite:28]{index=28}

Rhizobium — Fixes nitrogen in legume root nodules :contentReference[oaicite:29]{index=29}

Azospirillum and Azotobacter — Free-living nitrogen-fixing bacteria :contentReference[oaicite:30]{index=30}

Mycorrhiza — Symbiotic association between fungi and plant roots :contentReference[oaicite:31]{index=31}

Benefits of mycorrhiza — Improves nutrient uptake and plant growth :contentReference[oaicite:32]{index=32}

Cyanobacteria — Fix nitrogen in aquatic environments :contentReference[oaicite:33]{index=33}

Examples of cyanobacteria — Anabaena, Nostoc, Oscillatoria :contentReference[oaicite:34]{index=34}

Single Cell Protein (SCP) — Protein-rich microbial biomass used as food

Example of SCP — Spirulina

Role of microbes in environment — Decompose organic matter and recycle nutrients :contentReference[oaicite:35]{index=35}

Bioremediation — Use of microbes to clean pollutants :contentReference[oaicite:36]{index=36}