Question

Why are some microorganisms like bacteria and fungi important to humans?

Answer 1

Hint: Microbes are unicellular organisms that are too small to be able to view with naked eyes. They have a very important role in the environment. The bacteria and fungi are decomposers of organic matter. The dead organic matter is fed upon by these microbes and the inorganic nutrients and certain simple organic molecules are released into the environment (soil). Thus, they help in cycling of nutrients.
Apart from this, they secrete certain compounds or have certain roles which serve the purpose of human welfare.

Complete answer:
Some bacteria and fungi are important for mankind as they serve us with products and are useful in some anthropogenic aspects. Some of the importance of bacteria and fungi are:
1. IN HOUSEHOLD PRODUCTS: Bacteria and fungi are used in the manufacture and preparation of many household products such as curd, Cheese, Bread, etc. Curd is prepared with a group of Lactic Acid Bacteria (LAB). Different types of cheese are prepared with different types of microbes. E.g., Swiss cheese is prepared with the help of Propionibacterium shermanii; Roquefort cheese is ripened with the help of Penicillium roqueforti; Camembert cheese is ripened by Penicillium camemberti. Bread is prepared from dough, which is fermented using Baker’s yeast (Saccharomyces cerevisiae).
Other foods like dosa, idli, toddy (a famous south Indian drink), soya sauce, etc. are also prepared with the help of microbes.
2. IN INDUSTRY: In the industry, bacteria and fungi are used in preparation of wines, beer, rum, and other alcoholic beverages. These are all fermented products of molasses, sugarcane, grapes, potatoes (vodka), etc.
Many antibiotics are prepared with the help of bacteria and fungi. Bacitracin is an antibiotic prepared from the bacteria Bacillus licheniformis. Chlortetracycline, Erythromycin, Chloramphenicol, Penicillin, streptomycin, are notable antibiotics obtained from various species of fungi.
They are also in the production of organic acids like citric acid by the fungus Aspergillus niger; Acetic acid from Acetobacter aceti; lactic acid, Gluconic acid, Butyric acid.
Yeast is used in the commercial preparation of ethanol.
Certain enzymes like lipases, pectinases, proteases, streptokinase, amylase are obtained from microbes. An immunosuppressive agent known as Cyclosporin A is obtained from the fungus Trichoderma polysporum. Statins are cholesterol lowering agents obtained from the yeast Monascus purpureus.
Microbes are used in sewage treatment plants
Bacteria (methanogens) are used in the preparation of biogas.
They are used as biocontrol agents to control the pests and diseases in agricultural crops naturally without the use of fertilizers (concept of organic farming).
They are used as biofertilizers.

Note:
The learner must know about the significance of organic farming. The use of inorganic and chemical insecticides and pesticides is causing huge pollution to the environment, to the human beings, and to the animals. Thus, eventually the concept of organic farming evolved. It is the raising of crops with the help of biofertilizers and biocontrol agents. It holds the view that the eradication of creatures that are often described as pests is possible but is undesirable because without them the beneficial predatory and parasitic insects which depend upon them as food or hosts would not be able to survive. The microbes are natural organisms that check the pests and at the same time don’t cause any harm to mother nature.