The Vital Role of Bacteria in Life and Environment

 

2.7 – Importance of Bacteria

Bacteria are very important organisms not only for the environment (surroundings) but also for all other living things. They have beneficial (helpful) as well as harmful (disease-causing) effects.

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Beneficial Bacteria

1. Recyclers of Nature

• Bacteria play a role in biogeochemical cycles (natural cycles of essential elements).
• Nitrifying bacteria (Nitrosomonas, Nitrobacter, Azotobacter) → help in converting nitrogen into useful forms.
• Denitrifying bacteria (Pseudomonas) → complete the nitrogen cycle by releasing nitrogen gas.
• Decomposer bacteria → break down dead organic matter and recycle carbon, hydrogen, and oxygen.
• Photosynthetic bacteria (Cyanobacteria) → increase free oxygen in Earth’s atmosphere.

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2. Makers of Useful Products

• Lactobacillus (milk bacteria) with yeasts and molds → used in fermented foods: cheese, pickles, soy sauce, vinegar, wine, yogurt.
• Used in pharmaceutical (medicine-making) and agrochemical (farming chemicals) industry.
• Some bacteria produce antibiotics (disease-killing medicines).
• Used in the leather industry for softening animal skins.

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3. Environmental Cleaners

• Some bacteria degrade (break down) organic compounds → helpful in bioremediation (removal of pollutants).

• Used in:

  1. City sewage treatment → decomposed into harmless products.

  2. Oil spill cleaning → certain bacteria digest petroleum hydrocarbons.

  3. Industrial waste treatment → breakdown of toxic chemicals.

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4. Biopesticides

• Biological pest control (eco-friendly pest killing) uses bacteria instead of chemical pesticides.
• Example: Bacillus thuringiensis (soil bacterium) → kills harmful insects but safe for humans, wildlife, pollinators, and beneficial insects.

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5. Research and Technology Tools

• Bacteria grow fast → easy to study in labs.
• Used in molecular biology (study of molecules in life), genetics (study of genes), and biochemistry (study of chemicals in living things).
• Scientists create mutations (changes in DNA) to study gene functions.

• Human genes can be inserted into bacteria → production of therapeutic proteins (useful medicines) like:

  1. Insulin

  2. Growth hormones

  3. Antibodies

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✅ Exam Tip:
Always remember the keywords:

• Recyclers, Fermentation, Bioremediation, Biopesticides, Research tools.