Microorganisms: Viruses, Habitats, and Uses

• Common ailments like colds, influenza (flu), and most coughs can be caused by viruses.
• Serious diseases like polio and chickenpox are also caused by viruses.

Where Microorganisms Live

• Microorganisms spread over the entire biosphere.
• Examples of where they can be found include soil, water, air, and inside the bodies of animals, including humans.
• Microorganisms are characterized by a high degree of adaptability and can survive in all types of environment.
• Microorganisms can live in environments ranging from ice cold climates to hot springs and deserts to marshy lands.
• Some microorganisms grow on other organisms, while others exist freely.
• Amoeba can live alone, while bacteria and fungi may live in colonies.

Microorganisms and Us

• Microorganisms are have a dual role, offering benefits and causing diseases

Friendly Microorganisms

• Microbes are used for various purposes, including household products

Microbes in Household Products

• Curd contains several microorganisms, including the bacterium Lactobacillus, which promotes the formation of curd.
• Lactobacillus multiplies in milk and converts milk into curd, which is then added to rava idlis and bhaturas to make them soft and spongy.
• In the baking industry, dough is prepared by adding yeast to flour for making bread, cakes, and pastries.
• Yeast reproduces rapidly and produces carbon dioxide (CO2) during respiration, which fills the dough and increases its volume, adding sponginess to cake and bread.
• Bacteria are involved in the making of cheese, pickles, and other food items.
• Bacteria along with yeast are used for fermentation of rice idlis and dosa batter.

Commercial Use of Microorganisms

• Microbes are used for large scale production of alcohols, wine, and acetic acid (vinegar).
• Yeast is used for commercial production of alcohol and wine and grown on natural sugars in grains like barley, wheat, rice, and crushed fruit juices.
• The process of conversion of sugar into alcohol is called fermentation.
• Louis Pasteur discovered fermentation in 1857.

Medicinal Use of Microorganisms

• When an individual falls ill, doctors prescribe antibiotics for treatment.
• The source of antibiotic medicines and vaccines are microorganisms.

Antibiotics

• Antibiotics are medicines used to kill or stop the growth of disease-causing microorganisms.
• Antibiotics are available in the form of tablets, capsules, or injections and are products of microorganisms, mainly bacteria and fungi.
• Examples of antibiotics include penicillin, streptomycin, tetracycline, and erythromycin.
• Antibiotics are manufactured by growing specific microorganisms and are used to cure a variety of diseases.
• Antibiotics are mixed with the feed of livestock and poultry to check microbial infection in animals.
• They are also used to control many plant diseases.
• Antibiotics are not effective against colds and flu, which are caused by viruses.
• Antibiotics should be taken only on the advice of a qualified doctor in the proper dose.
• Taking antibiotics in wrong doses or unnecessarily can make them less effective in the future.