Bacteria

Bacteria are exceedingly minute organisms, a member of which is called bacterium. It is a large group of unicellular microorganisms having the simplest structure. They have cell walls but lack organelles and an organized nucleus. Many of them cause disease.

The first ones of these organisms discovered were rod-shaped, and therefore they are named bacterium or bacteria. However, these are merely cells of varied forms, in the shape of spheres, rods, or intermediate shapes, which develop in infusions of organic matter, and multiply by fission with great rapidity, fraught, as happens, with life or death to the higher forms of being.

They are widely distributed in soil, water and air. They are also found on or in the tissues of plants and animals.

These organisms are now classified as prokaryotes, but were formerly included in the plant kingdom.

They play a vital role in ecology by bringing about chemical changes that include those of organic decay and nitrogen fixation. Conspicuous by the part they play in the process of fermentation and in the origin and progress of disease, and to the knowledge of which, and the purpose they serve in nature, so much has been contributed by the labours of M. Pasteur. However, much modern biochemical knowledge has been accumulated by the study of bacteria that grow easily and reproduce rapidly in laboratory culture.

Nearby pages
Bacterial, Bactericidal, Bactericide, Bacteriocin, Bacteriologic