سلمان احمدی اسب چین

Background and Aim:One of the most important classes of hydrolytic enzymes is proteases which are widely used in biotechnological applications. Many different protease producers have been recently identified and their enzymes purified and characterized, but they are not sufficient to cope the demands of industrials processes. Due to the many harsh conditions in biotechnological processes such as high temperatures, acidic or alkaline pH, high salinity and etc., it would be great importance to recognize novel enzymes with optimum activities at extreme values of temperature, pH, and different concentration of salt. Methods:Samples were collected from water, soil, and sediments of two springs in Badab-sourt, Mazandaran. First different colonies have been isolated on MH media and optimal growth conditions of them were investigated. Then production of extracellular protease studied by cultivated on skimmed milk agar plates with both 5% and 10% NaCl concentration and incubated for two weeks in 37°C. Colonies with clear zone are considered to have proteolytic activity. Results:Results indicated only five isolates can produce extracellular protease by creating clear zone around their line culture. Based on biochemical and morphological characters, three isolates (S11, S13, and S18) were selected for further studied. S11 and S18 are non-motile, catalase-positive, oxidasepositive, indole-negative, aerobic, non-spore forming and Gram-positive bacillus. S13 is a non-motile, catalase-positive, oxidase-negative, indole-negative, aerobic, non-spore forming and Gram-negative Cocci, with orange pigments. Conclusion:Recently, considerable interest has been drawn on enzymes of halophilic bacteria and their biotechnological potentials. Aim of this study was isolation of halophiles which are able to produce extracellular protease.