Description of Sinobacter flavus gen. nov., sp. nov., and proposal of Sinobacteraceae fam. nov. Yu Zhou, 1 Yu-Qin Zhang, 2,3 Xiao-Yang Zhi, 2 Xu Wang, 1 Jing Dong, 1 Yun Chen, 2 Ren Lai 1,4 and Wen-Jun Li 2 Correspondence Wen-Jun Li wjli@ynu.edu.cn Ren Lai rlai72@njau.edu.cn 1 Key Laboratory of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, Life Sciences College of Nanjing Agricultural University, Nanjing, Jiangsu 210095, PR China 2 The Key Laboratory for Microbial Resources of the Ministry of Education, PR China, and Laboratory for Conservation and Utilization of Bio-Resources, Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091, PR China 3 Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, PR China 4 Biotoxin department of Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223, PR China A novel Gram-negative, non-motile, rod-shaped bacterium, designated CW-KD 4 T , was isolated from a polluted soil sample collected from Jiangsu Province, China, by using a classic enrichment method. Based on 16S rRNA gene sequence analysis, the novel strain represented a deep-rooting lineage within the class Gammaproteobacteria that was clustered with the genera Hydrocarboniphaga and Nevskia and some other unidentified bacteria. Polyphasic taxonomic studies revealed that strain CW-KD 4 T showed rather distant relationships to its phylogenetically closest neighbours, including the two recognized genera Hydrocarboniphaga and Nevskia. Strain CW-KD 4 T showed only 89.9 % and 89.7 % 16S rRNA gene sequence similarities to the type species of the genera Hydrocarboniphaga and Nevskia, respectively. The predominant isoprenoid quinone of strain CW-KD 4 T was Q-8 with minor components including Q-9, MK-7 and MK-6. The major fatty acids were C 16 : 0 ,C 18 : 1 v7c and summed feature 3. The G+C content of the DNA was 65.1 mol%. On the basis of its distinctive phenotypic and genotypic characteristics, strain CW-KD 4 T represents a new genus and a novel species in the class Gammaproteobacteria, for which the name Sinobacter flavus gen. nov., sp. nov. is proposed. The type strain is CW-KD 4 T (5DSM 18980 T 5KCTC 12881 T 5CCTCC AB 206145 T ). In addition, a new family, Sinobacteraceae fam. nov., is proposed to house the genus Sinobacter gen. nov. Modern agricultural practices have relied on the heavy, and sometimes unnecessary, application of chemicals. This has led to high levels of poisonous chemical and chemical intermediate residues in the environment. After pesticides come into contact with water, soils, plants or other environments, they can be cleaned up gradually by processes such as excursion, volatilization, photolysis, absorption, eluviation and biotic or abiotic decomposition (Petit et al., 1995). Micro-organisms can play active roles in the bioremediation of pollutants and representatives of many different genera such as Pseudomonas, Rhodococcus, Proteus, Bacillus, Candida and Achromobacter are well known as ‘pollutant-eating microbes’ that are able to utilize poisonous chemicals as sole sources of carbon and energy for growth (Zwillich, 2000; Ellis et al., 2006). The novel bacterial strain described in this study was isolated from a farmland soil near a chemical factory. The soil had been contaminated by different kinds of herbicides and insecticides over a long period (data not shown). The novel isolate represented a deep-rooting lineage belonging to the order Xanthomonadales which, at present, constitu- tes a single family, the Xanthomonadaceae. The novel isolate showed closest 16S rRNA gene sequence similarity with the established genera Nevskia and Hydrocarboniphaga (Stu ¨rmeyer et al., 1998; Palleroni et al., 2004). Based on the distinct genotypic and phenotypic properties when com- pared with members of the most closely related genera, the novel strain is proposed as representing a novel genus and Abbreviations: SEM, scanning electron microscopy; TEM, transmission electron microscopy. The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain CW-KD 4 T is EF154515. International Journal of Systematic and Evolutionary Microbiology (2008), 58, 184–189 DOI 10.1099/ijs.0.65244-0 184 65244 G 2008 IUMS Printed in Great Britain