Aquamicrobium terrae sp nov., isolated from the polluted soil near a chemical factory

A Gram-negative, aerobic, non-motile bacterial strain hun6(T) isolated from the polluted soil near a chemical factory in northern Nanjing, China was investigated to clarify its taxonomic position. Growth of strain hun6(T) occurred between 10 and 45 A degrees C (optimum, 30 A degrees C) and between pH 6.0 and 8.0 (optimum, pH 7.0). No growth occurred at NaCl concentrations greater than 5 % (w/v). The 16S rRNA gene sequence analysis indicated that strain hun6(T) belongs to the genus Aquamicrobium. The sequence similarities of strain hun6(T) to other type strains of Aquamicrobium genus were all below 98.5 %. The presence of ubiquinone-10, the predominant fatty acid summed feature 8 (C-18:1 omega 7c and/or C-18:1 omega 6c) and C-19:0 cyclo omega 8c, a polar lipid pattern with phosphatidylglycerol, phosphatidylcholine, diphosphatidylglycerol, phosphatidylethanolamine and phophatidylmonomethylethanoamine were in accord with the characteristics of the genus Aquamicrobium. The G+C content of the genomic DNA was determined to be 63.5 mol%. The results of DNA-DNA hybridization, physiological and biochemical tests and chemotaxonomic properties allowed genotypic and phenotypic differentiation of strain hun6(T) from all known Aquamicrobium species. Therefore, strain hun6(T) can be assigned to a new species of this genus for which the name Aquamicrobium terrae sp. nov. is proposed. The type strain is hun6(T) (= CICC 10733(T) = DSM 27865(T)).