Screening, Isolation, Purification and Characterization of haloalkaliphillic enzymes from Halomonas shengliensis

Abstract

A haloalkaliphillic bacterium isolated from saline soil of Khambhat was identified as Halomonas shengliensis based on 16s rRNA sequencing. The organism tested positive for extracellular enzymes Amylase, Protease and Lipase. Amylase activity was initially confirmed through starch-iodine assay and later confirmed through zymograph. Quantitative estimation of amylase was carried out through modified DNSA assay. Milk agar plate assay indicated positive protease activity. Zymograph for protease activity showed presence of 3 different proteases. Lipase screening was carried out using modified HM (Heterotrophic microorganism) media. Quantitative estimation of lipase activity was carried out spectrophotometrically by monitoring p-nitro phenol released by lipase from p-nitro phenyl acetate. Organism was also grown in presence of varying salt concentrations and the extracellular proteins were isolated and their crude activity was determined. Characterization of amylase in terms of its activity as a function of temperature showed 50˚C to be optimum for its activity.