What are Bacteria?

Bacteria belong to the lowest category of plants. There are about 1500 species of them. They are single called usually spiral, rod like or branched. They areas small as 25000 part of an inch and cannot be seen under an ordinary microscope.

Bacteria lack in chlorophyll and are unable to produce their own food. The yare therefore parasitic and or saprophytic. Some varieties are however autotrophic or self-nourishing, they have greenish or purplish pigment and are able to manufacture their own food.

Many varieties of bacteria cause diseases in plants, animals and even man. Typhoid, tetanus, diphtheria, pneumonia, T.B., dysentery, cholera are some of the diseases they can cause in man. Bacteria cause the bright disease in apples and pears, ring disease of potato, wilt of cocomber and melon, black rot of the decay of cooked food, meat, milk, vegetables and fruits.

Bacteria is useful in certain ways as they are natures scavengers. They help in the quick decay of dead plants and animals thus helping in converting them to valuable manure for the soil. They also convert the proteins in these decaying organic wastes to nitrates which are useful for plants.

In the industrial field too, bacteria help in a variety of ways. Curing and ripening of tobacco leaves, fermentation of tea leaves, ripening of cheese, preparation of vinegar, curdling of milk and conversion of hide into leather.

There are some species of bacteria which live permanently in our body. They guard us from disease producing germs.