Gordonia phthalatica sp nov., a di-n-butyl phthalate-degrading bacterium isolated from activated sludge

A phthalate esters-degrading bacterial strain, designated QH-11 (T), was isolated from an activated sludge wastewater treatment plant in Beijing, PR China. The cells were aerobic, Gram-stain-positive, non-motile, catalase-positive, oxidasenegative, short rods and formed white colonies on trypticase soy agar. This isolate contained meso-diaminopimelic acid as the diagnostic diamino acid and whole-cell hydrolysates contained arabinose and ribose. Diphosphatidylglycerol and phosphatidylethanolamine were the predominant polar lipids. According to the results of full-length of 16S rRNA gene sequence analysis, QH-11 (T) represented a member of the genus Gordonia and showed the highest sequence similarity to Gordonia hydrophobica DSM 44015 (T) (99.2 %), but was distinguishable by a low level of DNA-DNA relatedness (37.8 %). Genome-based comparisons indicated a clear distinction from the top ten most similar type strains (16S rRNA gene sequence) with pairwise average nucleotide identities (ANI) between 74.6 and 83.4 %. The predominant respiratory quinone was MK-9(H2), the mycolic acids present had 56 to 62 carbon atoms, and the major fatty acids were C-16 : 0 (33.3 %), C-17 : 1 omega 8c (23.4 %) and C-18 : 1 omega 9c (17.9 %). The DNA G+ C content was 68.0 mol%. On the basis of the results of DNA-DNA hybridization, ANI and physiological and biochemical tests, it is proposed that QH-11 (T) represents a novel species of the genus Gordonia, for which the name Gordonia phthalatica sp. nov. is proposed. The type strain is QH-11 (T) (CICC 24107 (T) = KCTC 39933 (T)).