Identification and Enzymatic Characterization of Hyperhalophilic Bacteria Isolatesfrom Howz Soltan Lake

The study of microorganisms in specific regions with specific characteristics has long been important. Howz Soltan is a salt lake in the central desert zone of Iran, which is considered as an area of great salinity. The present study was conducted to isolate halophilic bacteria from Howz Soltan lake in order to achieve maximum information concerning to microbial diversity of the lake.

For this purpose, samples were collected from five regions. Then the samples were diluted and cultivated on Molten haloid agar with different salt concentrations (5-35%). The plates were incubated at 37ºC in aerobic conditions. Biochemical characterizations, utilization of carbon sources and production of exoenzymes were investigated.

In total 205 different colonies were grew on medium with 5-35% salt concentrations. Of all isolates 18 strains were grew on medium with 15-35% salt concentrations. These strains were considered extreme halophilic bacteria and the rest were halotolerant and moderate halophilic bacteria. The results obtained from microscopic analysis of the isolates indicated that 178 isolates were gram positive bacilli, cocci and filamentous and 27 isolates were gram negative with bacilli shape. Phenotypic identification recognized that the isolated strains of extreme halophilic bacteria were Halobacterium ,Haloarcula ,Halorubrum and Halococcus. In addition, enzyme production assay of these strains showed some of them have capability to produce different enzymes viz., amylase, lipase, protease, DNase, urease, xylanase and gelatinase.

In general, our finding showed the huge diversity of halophilic bacteria in Howz Soltan lake. Furthermore, these bacteria could be considered as sources of halotolerant enzymes in different industries.