Microbial life is present not only in our familiar world but also in EXTREME environments. Salt lakes with near or at saturating salinity are EXTREME environments that common all over the world. The study in detail of such environments would permit to determine not only the microbial diversity but also the gene pools and potential use of this information for biotechnological applications. Urmia Salt Lake in the northwestern of Iran is the second saltiest lake in the world and resembles the Great Salt Lake in the western USA.Water, soil, sediment and salt samples were taken from east and western sites in Urmia Salt Lake in July 2012. Direct plating, dilution plating and long incubation period were used to isolate organisms on MGM, MH, SWN medium. Isolates were taken from the samples by using the conventional culture-dependent methods. Of these, 36 isolates were selected for sequencing and phylogenetic analysis, based on their growth characteristics and colony morphology. Two hundred and twenty-eight of MICROORGANISMS were obtained from soil, salt, water and sediment samples collected from the east and western of the lake. Of these, 36 isolates were selected for sequencing and phylogenetic analysis.Results showed that 36 strains represented 8 species, belonging to 3 generaHalorubrum, Haloarcula, Haloterrigena. As total, bacterial isolates were belonged to Salicola, Pseudomonas. All strains showed 96.5 to 100 % similarity in 16S rDNA sequencing. Of these, 5 strains showed less than 98.7% sequence similarity to the closest known strains and were representatives as new taxa of Urmia Lake.The phylogenetic analysis of sequences of Urmia Lake indicated in overlaps with 16S rDNA sequences from other lakes with similar habitats.

The aim of this study was to isolate HALOPHILIC and EXTREME HALOPHILIC bacteria from Incheh Borun saline water ecosystems including Alagol, Almagol and Ajigol wetlands, Shamushk and Shafi Abad dams, as well as Incheh and Qarniaraq volcanoes in Golestan province. The activity of amylase, protease and lipase enzymes was compared in them. The samples were isolated for 4 months from different areas with different EC and pH of the mentioned wetlands, dams and volcanoes. A total of 70 different water samples were collected from aquatic ecosystems that were purified by culturing on selected media. According to biochemical tests, 41 isolates were able to grow in saline environments, of which 63. 4% were halophiles, which were observed only in wetlands and another volcanoes 36. 6% were halotolerant and were excluded from the results. Alagol wetland had the highest abundance in HALOPHILIC species. The enzymatic activity of halophiles for amylase, protease and lipase hydrolase showed that 34. 6% of the isolates contained all three enzymes, which include all three groups of grampositive cocci, gram-positive and gram-negative bacilli. Comparison of enzymatic activity also showed that with the exception of two EXTREME species of Halophilus bacillus subtilis which were relatively slower in growth and had a longer period at the beginning and end of substrate application in culture medium, the rest of the isolates had almost the same range in growth time. They have the time of enzyme production and the time of completion of the substrate.

Owing to their superior catalytic activity in the EXTREME conditions, extremozymes have found the potential biotechnological applications for industrial purposes. A robust extracellular protease activity was detected in the culture broth of Salicola marasensis, an EXTREME HALOPHILIC bacterium, after a 48 h-incubation. The effect of different media ingredients in a liquid state fermentation was followed with the aim of improving the enzyme production yield. Fractional factorial and Box-Behnken designs were applied to get a 3.4 fold (from 6.0 to 20.3 U mL-1) improvement of protease production. The distinguishing features of this enzyme were stability at a wide range of pH (5.0–11.0) and temperature (25–60oC), significant compatibility towards organic solvents, metal ions, chemicals, and surfactants, and hydrolysis of a variety of substrates. The properties of this enzyme can be of tremendous help in terms of the HALOPHILIC proteolytic extract’s industrial applications.

The lake in the protected Bakhtegan zone is the shelter to wildlife and very important from an ecological and environmental viewpoint. The lake has a unique diversity in terms of HALOPHILIC and Halotolerant bacteria. Based on our experiments, from among the six genera ofHalobacteriaceae, only the four Halobacterium, Haloarcula, Halococcus, and Haloferax genera were isolated, the greatest frequency (mean: 54%) belonging to Halobacterium and the least frequency (mean: 4%) belonging to Haloferax among the isolated genera. The Halotolerant bacteria isolated included Pseudomonas sp., Flavobacterium sp., Micrococcus sp. and Bacillus sp. genera. The greatest number of Halotolerant bacteria isolated from the lake water was Pseudomonas (mean: 72%). Furthermore, the number of total coliforms was greater than the number of fecal coliforms. Statistical analysis revealed that HALOPHILIC and Halotolerant colonies had the same mean numbers only at Tashk and Gomban sampling sites but that the mean numbers obtained at Dehzir sampling site was significantly different from those obtained at the former two. It was also found that increasing salt concentration and pH level increased the number of HALOPHILIC colonies while increased levels of dissolved oxygen decreased their numbers.Salt concentration, pH level, and DO level had similar effects on the number of total and fecal coliform colonies.

In this work, the capacity of an EXTREME HALOPHILIC archaebacterium, isolated from Uromia lake, Haloferax radiotolerans to withstand the lethal effects of ultraviolet light (UV), and 60Co r-rays has heen studied. The resistibility of this organism against the DNA-damaging agents was evaluated by calculating of the survival fractions at different dose rates of UV and 60Co r-rays radiations and compared with those of Escherichia coli B/r (a radioresistant strain of E. coli). D37 values for Haloferax radiotolerans and E. coli B/r were 231, and 9 J/m2, respectively, by exposure to the UV light. They were 645, and 99 Gy, respectively, by exposure to 60Co r-rays. Against these agents, Haloferax radiotolerans shows much more resistance compare to that of E. coli B/r. This is catogorized as the first report of resistibility in the member of Archaea.

Pars Q2, an EXTREME HALOPHILIC archea bacterium isolated from the Namakdan salt lake on Qeshm Island, was capable producing biosurfactants to emulsify and degrade crude oil. In this article, the effects of salinity, pH, temperature, aeration (shaker speed) and the minimum optimized concentration of nitrogen and phosphate sources were studied on the bioremediation of crude oil. The results showed that 15-21% NaCl, pH 8.2, 35 oC and 140 rpm (shaker speed), 0.2 g of (NH4)2 So4 and 0.1 g. of KH2PO4 provided optimal conditions for oil biodegradation using this strain. Under such optimal conditions, the bacterium degraded 100% of the available crude oil after seven days of incubation.