Characterization of chitinases from microorganisms isolated from Lonar lake

357-363Chitinases, 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 pH (from 7.0 to 9.6) with a wide stability range from pH 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

An agar degrading diazotrophic actinobacteria from hyperalkaline meteoric lonar crater lake - a primary study

There are very few reports on agarases being produced by actinobacteria, Streptomyces coelicolor being the only one known since decades for its agar degrading property. Here we report an agar degrading diazotrophic actinobacterium other than Streptomyces coelicolor, isolated from the littoral soil of Lonar Lake situated in Buldhana district of Maharashtra, India, a lake characterised by high alkalinity, carbonates, bicarbonates, and algal blooms. The lake has a mean diameter of 1800 meters. The Gram-positive filamentous rod grew in a simple medium of pH 10.5 containing agar as a sole source of carbon. The agar degrading property was detected by the appearance of depressions around each colony after 48 h of growth. The enzyme responsible for this degradation, agarase was also detected and estimated. The isolate also grew on Ashby’s Nitrogen free Mannitol Medium aerobically and fixed nitrogen. Morphological, physiological and biochemical characteristics of the isolate are presented in this paper