Termiticidal activity of chitinase enzyme of Bacillus licheniformis , a symbiont isolated from the gut of Globitermes sulphureus worker

Chitinase is a digestive enzyme that breaks down glycosidic bonds in chitin. Chitin is a biopolymer that can be found in the exoskeleton of insects, fungi, yeast, and algae, and in the internal structures of other vertebrates. Bacillus licheniformis strain USMW10IK was isolated from the guts of Globitermes sulphureus workers. The production of chitinase was highest during the stationary phase (72-96 h of incubation) with the enzyme activity was 0.0057 U/mL - 0.0058 U/mL. The crude chitinase extracted after 72 h was used as biotermiticide against termite G. sulphureus. A pathogenic bioassay was done in four methods; no choice, treated sand medium, topical (Petri dish lined with filter paper), and topical (Petri dish lined with sterile sand). Termite mortality was observed for 24-48 h as the crude chitinase stability has decreased by 22.8% after 48 h. As a result, topical (Petri dish lined with filter paper) has caused significant termite mortality after 24 h and topical (Petri dish line with sterile sand) gave significant termite mortality after 48 h while no choice and sand treated medium gave no significant mortality. These findings suggest that chitinase is effective to be used as a biotermiticide when it directly contacts with the termite skin.