Historical Dates:

• 1928 — Alexander Fleming discovers penicillin from Penicillium notatum

Biogas Composition:

• Methane (CH4) — major component (primary fuel)
• Carbon dioxide (CO2)
• Hydrogen sulphide (H2S)
• Produced by methanogens (principally Methanobacterium) in anaerobic digesters

Cry Proteins (Bt toxin):

• Cry1Ac — effective against Helicoverpa, Heliothis (cotton bollworm, tobacco budworm)
• Cry2Ab — effective against Spodoptera (armyworm) and other lepidopteran pests
• Both encoded in Bt crop transgenes (e.g., Bt cotton)

Sewage Treatment BOD Impact:

• Primary treatment: minimal/no BOD reduction (physical only)
• Secondary treatment: significant BOD reduction (biological — aerobic microbes consume organic matter)

Enzyme Applications:

• Lipases + proteases → laundry detergents (active at low temperatures for energy efficiency)
• Pectinases → fruit juice clarification (apple, grape)
• Streptokinase → thrombolysis in myocardial infarction

Cholesterol Metabolism:

• Lovastatin (from Monascus purpureus) competitively inhibits HMG-CoA reductase — the enzyme that converts HMG-CoA to mevalonate, the rate-limiting step in cholesterol biosynthesis

Mycorrhiza:

• Primarily enhances uptake of: Phosphorus (P)
• Secondary benefits: Improved water absorption, resistance to soil-borne diseases
• Does NOT fix nitrogen

Nitrogen Fixers — Summary Table: