Marinobacter persicus sp. nov., a moderately halophilic bacterium from a saline lake in Iran

Abstract

A Gram-negative, non-endospore-forming, rod shaped, strictly aerobic, moderately halophilic bacterium, designated strain M9B^T, was isolated from the hypersaline lake Aran-Bidgol in Iran. Cells of strain M9B^T were found to be motile and produce colonies with an orange-yellow pigment. Growth was determined to occur between 5 and 20 % (w/v) NaCl and the isolate grew optimally at 7.5–10 % (v/w) NaCl. The optimum pH and temperature for growth of the strain were determined to be pH 7.0 and 35 °C, respectively, while it was able to grow over pH and temperature ranges of 6–8 and 25–45 °C, respectively. Phylogenetic analysis based on the comparison of 16S rRNA gene sequences revealed that strain M9B^T is a member of the genus Marinobacter. The closest relative to this strain was found to be Marinobacter hydrocarbonoclasticus MBIC 1303^T with a similarity level of 97.7 %. DNA–DNA hybridization between the novel isolate and this phylogenetically related species was 13 ± 2 %. The major cellular fatty acids of the isolate were identified as C_16:0, C_19:1 ω6c, C_18:1 ω9c and C_16:1 ω9c. The polar lipid pattern of strain M9B^T was determined to consist of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylserine and three phospholipids. Ubiquinone 9 (Q-9) was the only lipoquinone detected. The G+C content of the genomic DNA of this strain was determined to be 58.6 mol%. Phenotypic characteristics, phylogenetic analysis and DNA–DNA relatedness data suggest that this strain represents a novel species of the genus Marinobacter, for which the name Marinobacter persicus sp. nov. is proposed. The type strain of Marinobacter persicus is strain M9B^T (=IBRC-M 10445^T = CCM 7970^T = CECT 7991^T = KCTC 23561^T).