فهرست مطالب لیلا ستاری فقیهی

  Today, the ability to produce hydrolases enzyme that are active in high salt concentrations is considered a new approach to the use of halophilic bacteria in biotechnology. The aim of this study was the screening and isolation of extracellular lipase producing halophilic bacteria Marinobacter sp. S-14 isolated from Badab-e Surt Hypersaline spring. In this experimental study, 42 pure bacterial colonies were isolated from different samples of water, soil, sediment, and sludge from a hypersaline spring with a screening technique on the specific culture medium of halophilic bacteria. The isolate S-14, which showed the highest lipase activity, was selected for the identification by biochemical methods and 16S rRNA gene analysis. In order to optimize the growth conditions of the isolate, considering the maximum time of bacterial growth (72 hours), temperature, salt concentration, pH, carbohydrate, and amino acid intake were examined. The results were edited by Chromas pro 2.1.1 software, and compared with EzTaxon database. Strains that were more similar to the isolate were identified. Sequence analysis of 16S rRNA were performed by BioEdit 7.1.9, Clustal-2X 2.1, and MEGA 6, and the phylogenetic tree was drawn by the neighbor joining algorithm. The isolate S-14 had 99% similarity to Marinobacter flavimaris and Marinobacter adhaerens. The isolate had optimum growth in 5% NaCl concentration, 35°C, and 7.0 acidity. The isolate S-14 can be an appropriate candidate to produce extracellular lipase enzyme and can utilize Fructose and Phenylalanine as a sole source of carbon and energy.