Comparative bioefficacy of Bacillus and Pseudomonas chitinase against Helopeltis theivora in tea (Camellia sinensis (L.) O.Kuntze

Abstract

Tea (Camellia sinensis (L.) O.Kuntze) is an industry-oriented economical crop in India. Among the sap sucking pests, tea mosquito bug (Helopeltis theivora) is one of the most serious pests causing heavy crop loss in tea plantation. Continuous use of chemical pesticides causes environmental pollution and health hazards besides developing pesticide residues in tea powder. The control of pests by bacterial metabolite is an alternative that may contribute to reduce or eliminate the chemical pesticide use. The use of chitinase as a biological control is an emerging field of research. In the present study, Chitinase (~ 25 kDa) was purified from Bacillus cereus C-13 strain using gel-filtration chromatography and further characterized for its optimum pH, temperature and substrate specificity. Bioefficacy of chitinase from B. cereus C-13 was compared with our previously reported Pseudomonas fluorescens MP-13 chitinase against H. theivora. Result concluded that, 100% and 78% mortality was observed by using P. fluorescens MP-13 chitinase and B. cereus C-13 chitinase, respectively. In future, bacterial chitinase can be utilized in eco-friendly pest management strategies.