Sphingobium estronivorans sp. nov. and Sphingobium bisphenolivorans sp. nov., isolated from a wastewater treatment plant

Abstract

Two Gram-stain-negative, aerobic, motile and rod-shaped bacteria, one designated as strain AXBT, capable of degrading estrogens, and another, YL23T, capable of degrading estrogen and bisphenol A, were isolated from activated sludge in Xiamen City, PR China. The optimum temperature and pH of both strains were 25–35 °C and pH 7.0–8.0. While strain AXBT could tolerate 3 % (w/v) NaCl, YL23T could only grow between 0–1 % (w/v) NaCl. They contained ubiquinone-10 as the major quinone, spermidine as the major polyamine, summed feature 8 (comprising C18:1ω6c and/or C18:1ω7c) as the major fatty acids and diphosphatidylglycerol, phosphatidylcholine, phosphatidyldimethylethanolamine, phosphatidylethanolamine, phosphatidylglycerol and sphingoglycolipid as the major polar lipids. The DNA G+C contents of strains AXBT and YL23T were 63.6 and 63.7 mol%, respectively. Based on the results of 16S rRNA gene sequence analysis, strains AXBT and YL23T belonged to the genus Sphingobium . Strain AXBT was most closely related to Sphingobium chlorophenolicum NBRC 16172T (97.5 %) and Sphingobium chungbukense DJ77T (97.2 %), and strain YL23T was most closely related to S. chlorophenolicum NBRC 16172T (97.4 %) and S. quisquiliarum P25T (97.1 %). Average nucleotide identity values between these two strains and S. chlorophenolicum NBRC 16172T, S. chungbukense DJ77T, Sphingobium chinhatense IP26T, Sphingobium quisquiliarum P25T and Sphingobium japonicum UT26ST were from 80.7 to 85.8 %. In conclusion, strains AXBT and YL23T represent novel species of the genus Sphingobium , for which the names Sphingobium estronivorans sp. nov. and Sphingobium bisphenolivorans sp. nov. are proposed, respectively. The type strains of S. estronivorans and S. bisphenolivorans are AXBT (=MCCC 1K01232T=DSM 102173T) and YL23T (=MCCC 1K02300T=DSM 102172T), respectively.