List of Articles Halophile

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  1 - Phenotypic and Genotypic Studies of Halomonas sp. from Urmia Lake
  Sh. Irannejad A. Akhavan Sepahy M. A. Amoozegar A. Tukmechi R. Poori
  Urmia Lake is the second largest salt lake in the world and one scarce perennial hyper saline lake. It has wide biodiversity of halophile and halotolerant microorganisms. In this study, members of the genus Halomonas including moderate halophiles bacteria were isolated More

  Urmia Lake is the second largest salt lake in the world and one scarce perennial hyper saline lake. It has wide biodiversity of halophile and halotolerant microorganisms. In this study, members of the genus Halomonas including moderate halophiles bacteria were isolated from Urmia Lake and their phenotypic and genotypic properties were studied. Samples were collected from different sites of Urmia Lake and were transferred to the laboratory under sterile condition. Then Alkaline Peptone Water (APW), Nutrient Broth (NB), Nutrient Agar (NA), MacConkey Agar (MAC) supplemented with 5% and 10% salt were used for isolations. These cultures were incubated at 35-37 ˚C for 48h and repeated cultures were performed for achievement of pure cultures. Finally 80 isolates were produced. These isolates based on morphological characteristics and phenotypic surveyswere studied. Also biochemical, characterization and salinity tolerant tests were carried out on the isolated strains.For genotypic and phylogenetic studies, 15 isolates were selected for genetic experiment based on 16S rRNA gene sequence. Therefore genomic DNA of selective bacteria was extracted and was amplified by PCR technique. The results of sequencing 16S rRNA were edited by dependent softwares and sequences similarity of these strains were analyzed on comparison with registered strains in Gen-Bank of EzTaxon database. 6 isolates belonged to Halomonas sp. that phylogenetic tree was constructed by the neighbor-joining method. From the phylogenetic viewpoint, these strains belonged to Halomonas janggokensis, Halomonas gomseomensis, Halomonas boliviensis and Halomonas andesensis species. Sequence similarities of Halomonas janggokensis and Halomonas gomseomensis were more than 99%. Sequence similarities for Halomonas boliviensis and the half of isolated Halomonas andesensis showed between 97% and 98.9%. The half of other Halomonas andesensis indicated 94.2% . Manuscript profile
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  2 - Production and characterization of a thermophilic and extremely halotolerant alpha-amylase isolated from Anoxybacillus gonensis AT23
  Saeedeh Afrisham Arasto Badoei Delfard Abdolhamid Namaki Shoshtari Zahra Karami
  Background & Objectives: Thermophilic alpha-amylase can be used in different industries such as starch processing and detergents. This study was performed to isolate alpha-amylase-producing bacteria and characterization of the enzyme. Materials & Methods: After More

  Background & Objectives: Thermophilic alpha-amylase can be used in different industries such as starch processing and detergents. This study was performed to isolate alpha-amylase-producing bacteria and characterization of the enzyme. Materials & Methods: After sample collection from Gorooh hot spring in Kerman province, Iran, thermophilic alpha-amylase- producing bacteria were isolated using the starch-agar medium. 16S rDNA sequencing was used to identify the bacterial strain. Characterization of the thermophilic alpha-amylase was performed in the presence of various factors such as pH, temperature, metal ions, chemical compounds, and organic solvents. Also, kinetic parameters of the enzyme were determined in different concentrations of starch. Results: Anoxybacillus gonensis AT23 was identified as the best thermophilic alpha-amylase- producing strain. The alpha-amylase enzyme showed the optimal activity at pH 5 to 6. Sevenfold increase in the enzyme activity was observed in the presence of NaCl (3M). Mn2+ and Zn2+ increased the enzyme activity about 95% and 31%, respectively. Kinetic parameters including Km and Vmax were estimated about 1.657 mg/ml and 0.0059 mg/ml/min, respectively. Also, enzyme activity was also improved about 2 folds in the presence of organic solvents including n-butanol and 10% cyclohexane. Conclusion: Our results indicated that AT23 alpha-amylase is a halophile and organic solvent-tolerant enzyme. Therefore, it can be used in different industries. Manuscript profile