الملخص الإنجليزي
Strains of indigenous, extremely halophilic microorganisms were isolated from oil contaminated soils and water with the aim of finding microbial degraders of hydrocarbons in the laboratory. The nine strains provided for this study were characterized by means of many phenotypic features. According to the physiological, biochemical and antibiotic susceptibility results, the nine isolates were divided to three groups. The growth rate of the three groups were checked. Two of the isolates tested (ST1S2 and SYTC) had close generation times of 3.84 and 2.87 h, respectively. The third isolate (HIYTC) was the slowest, having a generation time of 12.8 h. Morphologically, the isolates are Gram-negative facultative anaerobic rod with a single central flagellum. Only two of the isolates (HIYTC and HBNSi) exhibited pleomorphism with changing the medium salinity. The other isolates maintained their well-defined rod-shape with changing salt medium concentrations. Polar lipid analysis revealed that the representative isolates contained the diether analogues of phosphatidylglycerol (PG) and the phosphatidylglyceromethylphosphate (Me-PGP). The ultrastructure of the isolates revealed the presence of a cell wall and all the isolates tested were ampicillin-sensitive. Since ampicillin inhibits cell wall growth, we suggested that the isolates tested are not halophilic Archaea but belong to the halophilic Bacteria. Although the exact mechanism of degradation of hydrocarbons in hypersaline environments is not yet well known, the results from GC/MS analysis provides several indications that one of the strains tested can act as a biodegrader.
