ABSTRACT
Bacteria secrete and release certain metabolites, which help them to derive nutrients from their surrounding environments, to play a role in disintegration of host tissues and symptoms developments, or to survive in a competitive habitat. These metabolites can be enzymes, toxins, bacteriocins, and so forth. Bacterial cells are harvested by centrifugation and the supernatant thus obtained is termed total cultural filtrate. In the cell, tabtoxin is cleaved releasing the tabtoxinine moiety which is an active toxin in the inhibition of the enzyme glutamine synthetase and this is the primary mode of action of the toxin. Cellulases are produced by several phytopathogenic fungi and bacteria. In living tissues, these play an important role in softening or disintegration of the cell wall material, thus facilitating penetration and spread of pathogen. The extraction of cellulases is done from an infected host plant. Pectic substances composed mainly of galacturonic acid units are found in plant’s primary cell wall and middle lamella.
