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Aims: Carotenoids are a vast group of lipid-soluble pigments, which are produced by variety of microorganisms. The aim of this study was to compare the production of carotenoid pigments by prokaryotic isolates of Iranian saline ecosystems and identify superior isolate.
Materials & Methods: In this the experimental study, isolates were purified by culture-based methods and carotenoid extracts were analyzed by spectrophotometry in wavelength region of 400nm to 600nm. The total carotenoid content was estimated by spectrophotometry at λ_max (490nm). Identity of bands was detremined by purification of bands by Thin Layer Chromatography (TLC) and analysis by High Pressure Liquid Chromatography (HPLC) and Fourier Transform Infrared Spectroscopy (FTIR).
Findings: Fourty-three isolates were obtained. Eight isolates were halotolerant bacteria, 8 isolates were moderately halophile, and 27 isolates were extremely halophile. All of the strains were capable of producing carotenoid compounds. Isolate M24 with 2054μg/g production was selected as superior isolate. Thin layer chromatography exhibited 6 colored bands in colored extract of this strain and the most concentrated band was purified. After purification by TLC and HPLC, spectrophotometry in UV range showed two pics at 530nm and 465nm as the highest absorbances, which were similar to UV absorbance of α-bacterioruberin. Phylogenetic analysis of 16S rRNA gene sequence of strain M24 showed that this strain had 98% similarity with Haloarcula amylolytica BD-3.
Conclusion: From Iranian Saline Ecosystems, 43 isolates are obtained. Eight isolates are halotolerant bacteria, 8 isolates are moderately halophile, and 27 isolates are extremely halophile. All of the isolates are capable of producing carotenoid compounds. Strain M24 is superior isolate, having 98% similarity with Haloarcula amylolytica BD-3.

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Aims: Peroxidases are used in a wide range of biotechnological processes, most of which are carried out at high temperatures and high pH levels. Since most of the commonly used peroxidases are unstable and inactive in alkaline conditions and high temprature, it is necessary to find thermoalkalophilic peroxidases for practical purposes.
Materials and Methods: In this study, extracellular production of peroxidase in the native strain Bacillus tequilensis was studied. for this purpose, Enzyme activity was evaluated using two substrates 2,4-DCP and pyrogallol in bacterial liquid culture and the effect of culture time on enzyme production, as well as the effect of parameters such as pH and temperature on enzyme activity investigated. The relative purification of the enzyme was performed using ion exchange chromatography with sephadex DEAE A50 and the kinetic parameters of enzyme activity were evaluated. In this study, kinetic parameters such as Km and Vmax were calculated.
Results: Measurement of enzyme activity at different times of culture indicated that the highest amount of peroxidase production was obtained 72 h after bacterial culture.