جداسازي و شناسايي باكتري هاي نمك دوست نسبي و بررسي اثر تغييرات دما و pH محيط كشت بر رشد آن ها

Isolation of the moderately halophilic bacteria and effects of pH and incubation on their growth

Micro organisms that grow in habitats characterized by high or low temperatures, acidic or alkaline pHs, high salt concentrations and high pressures have been termed extremophiles. The halophilic microorganisms are a group of extremophiles that are able to grow in the presence of NaCl. For isolation of moderately halophilic bacteria, specimens were collected from sea water (Persian Gulf) and different parts of tannery factory. Samples were enriched in specific medium for halophils, and bacteria were purred with streak plate method and were identified. To investigate the effects of various temperatures and various pH on their growth, drop plate method and microtitre plate method were used. In this study, 8 bacteria from different parts of tannery factory and 8 bacteria from Persian Gulf were isolated. Phenotypic and biotipic studies were accomplished the collected bacteria. Results indicated that, the best temperature for tannery factory and Persian Gulf isolates were 28°C and 37°C respectively. Optimum pH for tannery factory and Persian Gulf isolates was 7.2.