Screening and Characterization of Halotolerant Bacteria Producing Extracellular Lipase Isolated from the Caspian Sea in Mazandaran, IRAN

Introduction and objectives: Halophilic bacteria are microorganisms that require from 3 to 15% w/v NaCl for sufficient growth. Halophilic microorganisms are potential sources of enzymes with wide application in beverages, pharmaceutical and detergent industries. The aim of the study was to isolate and study the halophilic bacteria producing industrial enzymes. Screening of halophilic bacteria from the coast of Caspian Sea led to isolation of 20 strains and characterization of 9 potential isolates producing industrially important hydrolases. Materials and methods: Water samples were collected from the Caspian Sea and stored in suitable condition. Sea Water Media was used for screening of halophilic bacteria. Isolates were cultured in a lipase specific media to screen lipase producing bacteria. The strain produced maximum lipase enzyme qualitatively was chosen for further microbial works. Morphology, biochemical and molecular characteristics and production of hydrolase enzymes of the strain was studied. Optimization of growth for the designated isolate was studied in different pH, NaCl concentration and temperature, then determined spectrophotometrically at 600 nm and stated as microbial biomass. Results: The isolate is a gram - negative strain related to Psuedoalteromunas sp. which is able to produce important hydrolases such as protease, Lipase and etc. The optimization of growth conditions determined that the strain is able to grow at 35℃ and pH=7 with 4% NaCl concentration which revealed that this isolate is a halotolerant bacterium. Conclusion: From this present study it can be inferred that the isolate is a strain which can produce lipase enzyme in high quantity.

کلیدواژه ها:

Halotolerant bacteria ، Lipase enzyme ، Industrial applications