Characterization of chitinases from microorganisms isolated from Lonar lake

Abstract

Chitinases, the enzymes that breakdown chitin—the second most abundant polysaccharide in nature—are known to have numerous uses. Alkaline chitinases, in particular are considered to have a greater potential in this respect. Fifteen chitinolytic microbial strains were isolated from the alkaline soil of Lonar lake in Buldhana district of Maharashtra. In this paper, the characters of chitinases produced by the five most potent isolates are presented. All the enzymes exhibited maximum activity in the neutral to alkaline range of <i style="">p</i>H (from 7.0 to 9.6) with a wide stability range from <i style="">p</i>H 4 to 11. The temperature optima for all the enzymes were slightly on the higher side, between 35 and 60°C, with a stability range from 25 to 60°C. All the enzymes showed a typical response to substrate concentration. None of the enzymes had any specific requirement for any particular metal ion, though a considerable stimulatory effect of Ca²⁺ was observed on all the enzymes. Minor effects of Cu²⁺, Mn²⁺ and Na¹⁺were also observed on some of the enzymes.