Predominant activities of bacteria

ACTIVITIES

Following are some of the predominant activities of bacteria, namely :

(a) Enzyme Production. Bacteria invariably give rise to the production of enzymes that act on complex food molecules, breaking them down into much simpler components ; they are the principal agents responsible for causing decay* and putrefaction.**

(b) Toxin Production. Special molecules called adhesins bind bacteria to the host cells. Once the attachment gets materialized, the bacteria may produce poisonous substances usually known as toxins.

Toxins are commonly of two kinds, such as :

(i) Exotoxins — enzymes that virtually disrupt the cell’s function or kill it, and

(ii) Endotoxins — stimulate production of cytokines*** which may produce widespread vasodilation and shock.

(c) Miscellaneous. A host of bacteria produce several chemical and physical characteristic prod-ucts, such as :

Pigments — colouring matter,

Light — exhibiting luminescent at night,

Chemical substances — e.g., acids, alcohols, aldehydes, ammonia, gases, carbohydrates, and indole, and

Hemolysins, leukocidins, coagulases, and fibrolysins — produced by pathogenic bacteria ;

The soil bacteria play a vital and important role in different phases of the nitrogen cycle viz., nitrification, nitrogen fixation, and denitrification.