Abstract :

Microbial chitinases are important environmental biomolecules with biotechnological and medicinal applications in addition to being a source of environmental friendly biopesticides. They are considered as safe alternatives to some available chemical insecticides, especially against insects that may act as an intermediate hosts as well as vectors between manifested plant materials and humans. A crude chitinolytic enzyme was isolated from isolate A7 (Bacillus atrophaeus Nakamura 1989). The isolate was identified based on the morphological and biochemical characteristics as well as the sequencing of 16S rRNA. The produced enzyme had a total activity of 68.9±1.03 mU/mL; a specific activity of 2670±40.2 mU/mg protein, and was optimally active at 40°C, 4-9 pH with stability for one hour at 30-40°C and 6-7 pH. It was inhibited by Cu2+, Fe3+, Ni3+, Zn2+ and Ba2+ metal ions and impeded the development of 50 % of Drosophila melanogaster larvae into adults (LD50) at 17.3±1.4 mU/mL. In this study, the larvicidal activity of chitinase from B. atrophaeus is explored for the first time with the potential of being applied as environmental friendly biopesticide technologies.