Pseudoxanthomonas jiangsuensis sp. nov., a DDT-degrading bacterium isolated from a long-term DDT-polluted soil

A Gram-negative, strictly aerobic, rod-shaped bacterium, designated strain wax^T, was isolated from DDT-contaminated soil in Yangzhou, China. Growth of strain wax^T was observed at 10-45°C (optimum 30°C) and pH 5.0-10.0 (optimum pH 7.0-8.0). The predominant fatty acids were iso C_15:0 (32.21%) and anteiso C_15:0 (22.2%). The strain contained large amounts of the polar lipids diphosphatidylglycerol, phosphatidylethanolamine, and phosphatidylglycerol, but small amounts of an unknown amino-group-containing polar lipid and phospholipids were also present. The major quinone was ubiquinone-8 (Q-8) and the G + C content of the genomic DNA was 67.12 ± 0.8 mol.%. The phylogenetic tree shows that strain wax^T clustered within the genus Pseudoxanthomonas. Isolate wax ^T showed moderate 16S rRNA gene sequence similarities to Pseudoxanthomonas broegbernensis B1616/1^T (98.3%), P. suwonensis 4M1^T (98.2%), P. daejeonensis TR6-08^T (98%), P. koreensis TR7-09^T (97.7%), P. kaohsiungensis J36^T (97.5%), P. mexicana AMX 26B^T (97.2%), and P. japonensis 12-3^T (97%). The level of DNA-DNA relatedness between strain wax^T and Pseudoxanthomonas type strains were low, e.g., P. koreensis TR7-09^T (25.9%), P. broegbernensis B1616/1^T (36.4%), P. suwonensis 4M1 ^T (27.7%), P. daejeonensis TR6-08^T (40%), P. kaohsiungensis J36^T (20.4%), P. mexicana AMX 26B^T (29.0%), P. japonensis 12-3^T (33.3%). On the basis of the phenotypic, chemotaxonomic data and molecular properties, strain wax^T represents a novel species within the genus Pseudoxanthomonas, for which the name Pseudoxanthomonas jiangsuensis sp. nov. is proposed. The type strain is wax ^T (=DSM 22398^T = CGMCC 1.10137^T).