On the Diversity and Biogeography of Haloalkaliphilic Bacterial Communities Producing Alkaliphilic Protease

Abstract

Haloalkaliphilic bacteria are a specific group of bacteria known to us. The diversity of microorganisms is critical to the functioning of the ecosystem as there is the need to maintain ecological process such as decomposition of organic matter, nutrient cycling, soil aggregation and control of pathogens within the ecosystem. Microbial diversity as an indicator of the quality of agroecosystems has been widely debated, In the present study various saline soil samples collected from Bhavnagar and Uncha Kotda, Gujarat, India. The collected five samples were analysed for diversity study of soil sample for physicochemical analysis like pH, redox potential, conductivity, humidity, salinity and soil analysis for total nitrogen and organic carbon analysis also. Total 55 haloalkaliphilic bacterial morphotypes were isolated and screened for alkaline protease production on halophilic agar medium. Out of them 76.4% gram positive bacilli, 21.8% gram positive cocci and 0.0002% were gram negative short rods. From total 55 morphotypes 33% were different morphotypes, 8% were zone of casein producer, and 16% of them were pigment producing morphotypes. All the pigmented colony producer morphotypes showed growth of orange, yellow, red, light pink and light-yellow colonies on 15%, 20%, 25%, 30% NaCl containing medium. Dominantly bacilli were found in all five samples. Diversity indices for metabolic characterization studies like Shannon-weiner index (H’), Richness, Evenness, Cho-1, Simpson’s index and Good’s coverage were calculated based on the site wise obtained different morphotypes. Phenotypic characteristics were studied. The secondary screening and tertiary screening were done on the basis of REA and different NaCl concentration accordingly. Identification of all haloalkaliphilic protease producers were confirmed by 16S r-RNA identification.