Definitions [5]
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.
Definition: Zymology
Zymology is the applied science that deals with the biochemical processes of fermentation and their practical uses.
Definition: Oenology
Oenology is the science and study of wine and winemaking.
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
- Industrial fermentation uses large, controlled vessels to cultivate microbes for the large-scale production of valuable secondary metabolites.
- Yeast (Saccharomyces cerevisiae) ferments sugars in cereals and fruit juices to produce non-distilled (wine and beer) and distilled (whisky and rum) alcoholic beverages.
- Specific microbes convert carbohydrates into commercial organic acids, such as Aspergillus niger for citric acid and Lactobacillus for lactic acid.
- Microbes are utilized to commercially synthesize essential vitamins, like vitamin B12 and riboflavin, which humans cannot produce naturally.
- Certain microbes produce antibiotics, like penicillin, which are chemical substances that kill or inhibit the growth of disease-causing pathogens.
- Microbial enzymes act as commercial biocatalysts, functioning in detergents (lipases), juice clarification (pectinases), and medicine (streptokinase).
- Microbes produce critical bioactive molecules for medicine, including immunosuppressive agents (Cyclosporin A) and cholesterol-lowering drugs (statins).
- Fungi (Gibberella fujikuroi) synthesize gibberellins, which are agricultural hormones used to promote plant stem elongation and break seed dormancy.
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 - The sedimentation tank settles suspended solids and reduces coliform bacteria. Removes ~50–70% solids.
- Secondary Treatment - Aerobic bacteria decompose organic matter in aeration tanks, lowering BOD by 70–80%.
- Tertiary Treatment - Anaerobic bacteria digest sludge in sludge digesters; disinfection improves water quality.
- Chlorination kills any remaining pathogenic bacteria before water is released.
- Disposal - Treated water → natural water bodies; digested sludge → proper disposal/manure.
