SALINITY DEPENDENT PRODUCTION OF EXTRACELLULAR AMYLASE, PROTEASE, AND LIPASE BY HALOPHILIC MICROORGANISMS ISOLATED FROM A SALTPAN

Abstract

Saltpan ecosystems are extreme hypersaline habitats that harbor diverse halophilic and halotolerant microorganisms capable of producing salt-stable enzymes with significant biotechnological potential. In the present study, microorganisms isolated from a solar saltpan were screened for extracellular amylase, protease, and lipase production under varying sodium chloride (NaCl) concentrations. Qualitative enzyme activity was assessed by the zone of hydrolysis on selective agar medium, whereas quantitative enzyme production was determined under optimized salinity conditions. Among the tested isolates, Halobacillus spp., Gracilibacillus spp., and Bacillus licheniformis showed superior enzymatic potential. The maximum quantitative enzyme activities were recorded for Bacillus licheniformis at 7.5% NaCl with protease (54.93 ± 2.91 U/ml), amylase (41.20 ± 2.60 U/ml), and lipase (23.60 ± 1.05 U/ml). These results demonstrate that saltpan-derived microorganisms are promising candidates for the industrial production of halotolerant and halo-stable enzymes.