Activities of a Cellulase of the Termite, Ametermes Eveuncifer (Silverstri) Soldier: Clue to Termites Salt Intolerance

Abstract

Table salt which contains predominantly NaCl is both toxic and lethal to termites and is therefore used to control the insect traditionally. In an attempt to find out a scientific explanation for this treatment and possibly design a pesticide for the destructive insect, we carried out some tests on the effects of NaCl (table salt), some other chloride and sodium salts on some important enzymes produced by termites. At 0.1mM concentration, all the chloride salts inhibited all the enzymes. Acid phosphatase and arginase were however mildly inhibited. Interestingly, some chloride salts were more potent than NaCl the conventional pesticide.  The greatest inhibition was by the chlorides of mercury (81%), manganese (78%), and sodium (76%). The inhibitory effect was more on cellulolytic enzymes; β-glucosidase and cellulase than on detoxifying enzymes; 3-MST and rhodanese. Again, all the sodium salts tested inhibited cellulase drastically with most of them more potent than NaCl. Thus both the sodium and chloride ions contributed immensely to the inhibition. Form these discoveries, one of the chloride salts of mercury, manganese and sodium or a combination of at least two can be used as a pesticide for termites. Almost all the sodium salts tested or a combination of at least two can also be used.

Keywords: cellulase, cellulose, termites, salts, insects, enzyme.