MICROBES IN HUMAN WELFARE

INTRODUCTION

Microbes are the major components of biological systems on this earth.

Microbes are present everywhere -- soil, water, air, inside the body of plants and animals, inside thermal vents, deep in the soil, under the layers of snow several meters thick and in highly acidic environments.

Microbes are diverse such that they are protozoa, bacteria, fungi and microscopic plants viruses, viroids and prions.

Microbes like bacteria and many fungi can be grown on nutritive media to form colonies which can be seen with naked eyes.

Microbes -- diseases in human beings, animals and plants.

 several microbes are useful to man in diverse ways.

MICROBES IN HOUSEHOLD PRODUCTS

1. Production of curd

• Milk -- curd by micro-organisms, Lactobacillus and others commonly called lactic acid bacteria (LAB).
• Process - curdling

• During growth of bacteria, the LAB -- acids -- coagulate and partially digest the milk proteins.

• A small amount of curd -- the fresh milk as inoculum or starter -- at suitable temperatures multiply -- converting milk to curd

•  improves its nutritional quality by increasing vitamin B12.
• In our stomach, the LAB play very beneficial role in checking disease causing microbes.

2. Fermentation

• The dough ( used for making foods such as dosa and idli ) is also fermented by bacteria.
• The puffed-up appearance of dough is due to the production of CO2
• The dough, which is used for making bread, is fermented using baker’s yeast (Saccharomyces cerevisiae).

• A number of traditional drinks and foods are also made by fermentation by the microbes.
• Toddy, a traditional drink of some parts of southern India is made by fermenting sap from palms.

• Microbes are also used to ferment fish, soya bean and bamboo shoots to make foods.

3. Production of cheese

• Different varieties of cheese --different texture, flavor and taste, the specificity coming from the microbes used.
• The large holes in ‘Swiss cheese’ are due to production of a large amount of CO2 by a bacterium named Propionibacterium sharmanii.

• The ‘Roquefort cheese’ are ripened by growing a specific fungi on them, which gives them a particular flavor.

Formation of cheese