ORIGINAL PAPER Rhodococcus biphenylivorans sp. nov., a polychlorinated biphenyl-degrading bacterium Xiaomei Su • Yindong Liu • Muhammad Zaffar Hashmi • Jinxing Hu • Linxian Ding • Min Wu • Chaofeng Shen Received: 2 September 2014 / Accepted: 7 October 2014 / Published online: 15 October 2014 Ó Springer International Publishing Switzerland 2014 Abstract A Gram-positive, aerobic, non-motile and rod–coccus shaped novel actinobacterial strain, desig- nated as TG9 T , was isolated from a polychlorinated biphenyl (PCB)-contaminated sediment in Taizhou city, Zhejiang province, eastern China. The isolate was observed to grow at 10–45 °C (optimum 28–32 °C), pH 5.0–11.0 (optimum pH 7.0–8.0) and with 0–9.0 % (w/v) NaCl (optimum 0–3.0 %). Comparison of the 16S rRNA gene sequences of strain TG9 T and other members of the genus Rhodococcus showed that strain TG9 T shared highest similarities with Rhodococcus pyridinivorans DSM 44555 T (99.4 %), R. rhodochrous DSM 43241 T (99.2 %), R. gordoniae DSM 44689 T (99.2 %) and R. artemisiae DSM 45380 T (98.2 %). However, low levels of DNA–DNA relatedness (15–48 %), which are below the 70 % limit for prokaryotic species identification, were obtained by DNA–DNA hybridization. Strain TG9 T was found to contain meso-diaminopimelic acid as the diagnostic diamino acid and arabinose and galactose in the whole- cell hydrolysate. Mycolic acids were found to be present. The major fatty acids were identified as C 16:0 , C 16:1 x7c and/or iso-C 15:0 2-OH, 10-methyl C 18:0 and C 18:1 x9c. The only menaquinone detected was MK-8 (H 2 ). The major polar lipids detected were diphosphat- idylglycerol, phosphatidylethanolamine, phosphatidyl- inositol, glycolipid and traces of some unknown lipids. The genomic DNA G?C content of strain TG9 T was determined to be 62.8 %. The combined phenotypic and genotypic data show that the strain represents a novel species of the genus Rhodococcus for which the name Rhodococcus biphenylivorans sp. nov. is proposed, with the type strain TG9 T (=CGMCC 1.12975 T = KCTC 29673 T = MCCC 1K00286 T ). Keywords Rhodococcus biphenylivorans sp. nov. Á Viable but non-culturable Á Extracellular organic matter Á Polychlorinated biphenyl (PCB)- contaminated sediment Introduction The actinomycete genus Rhodococcus was classified into the family Nocardiaceae of the suborder Coryne- bacterineae (Stackebrandt et al. 1997). Members of Electronic supplementary material The online version of this article (doi:10.1007/s10482-014-0303-4) contains supple- mentary material, which is available to authorized users. X. Su Á Y. Liu Á M. Z. Hashmi Á J. Hu Á C. Shen (&) Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866#, Hangzhou 310058, China e-mail: ysxzt@zju.edu.cn; purple@zju.edu.cn L. Ding College of Geography and Environmental Science, Zhejiang Normal University, Jinhua 321004, China M. Wu College of Life Sciences, Zhejiang University, Hangzhou 310058, China 123 Antonie van Leeuwenhoek (2015) 107:55–63 DOI 10.1007/s10482-014-0303-4