Definitions [3]
Define the following term
Zymology
Zymology is an applied science which deals with the biochemical process of fermentation and its practical uses.
Define the following term
Antibiotics
Antibiotics are chemical substances produced by microorganisms which can kill or retard the growth of other disease causing microbes even in low concentration. Antibiotic means “against life”.
Define the following terms
Superbug
"Superbug" is a term used to describe strains of bacteria that are resistant to the majority of antibiotics commonly used today.
Key Points
Key Points: Microbes in Household Products
| Product | Micro-organisms Used | Function |
|---|---|---|
| Curd | Lactobacillus (LAB) | Converts milk into curd, increases vitamin B₁₂ |
| Butter | Streptococcus cremoris, Leuconostoc dextranicum | Gives flavour and aroma |
| Yogurt | Lactobacillus bulgaricus, Streptococcus thermophilus | Ferments milk at 40°C |
| Cheese | Streptococcus lactis, Leuconostoc, fungi | Curdling and ripening of cheese |
| Swiss Cheese | Propionibacterium shermanii | Produces CO₂, forms holes |
| Roquefort Cheese | Penicillium roqueforti | Ripening and flavour |
| Camembert Cheese | Penicillium camemberti | Soft texture and taste |
Key Points: Microbes in Industries
- Bio-active Compounds — Streptokinase (Streptococcus) = clot buster; Statins (Monascus purpureus) = lowers blood cholesterol.
- Antibiotics — Penicillin (Penicillium chrysogenum), Streptomycin (S. griseus), Erythromycin (S. erythreus), Oxytetracycline (S. aurifaciens), Bacitracin (Bacillus licheniformis).
- Alcoholic Beverages — Yeast (Saccharomyces cerevisiae) ferments cereals/fruit juices. Distilled = Whisky, Brandy, Rum; Non-distilled = Wine, Beer. Fenny = Goa's cashew wine.
- Organic Acids — Citric & Gluconic acid (Aspergillus niger), Acetic acid/vinegar (Acetobacter aceti), Fumaric acid (Rhizopus arrhizus).
- Vitamins — B₂ (Neurospora gossypii), B₁₂ (Pseudomonas denitrificans), Vitamin C (Aspergillus niger).
- Industrial Enzymes — Invertase (S. cerevisiae), Lipase (Candida lipolytica), Cellulase (Trichoderma konigii), Pectinase (Aspergillus niger).
- Gibberellins — Isolated from fungus Gibberella fujikuroi; ~15 types; used for parthenocarpy, seed dormancy breaking, flowering induction & enlarging grape fruits.
Key Points: Microbes in Sewage Treatment
- Sewage = 99.5–99.9% water + 0.1–0.5% organic/inorganic matter + microbes (bacteria, viruses, fungi, algae, etc.)
- Preliminary Treatment — Bar screens remove large solids; Grit Chamber removes sand & stones.
- Primary Treatment — Sedimentation tank settles suspended solids; reduces coliform bacteria. Removes ~50–70% solids.
- Secondary Treatment — Aerobic bacteria decompose organic matter in aeration tanks; lowers BOD by 70–80%.
- Tertiary Treatment — Anaerobic bacteria digest sludge in sludge digesters; disinfection improves water quality.
- Chlorination — Kills remaining pathogenic bacteria before water release.
- Disposal — Treated water → natural water bodies; digested sludge → proper disposal/manure.
