Piscinibacter Caeni Sp Nov., Isolated From Activated Sludge

A yellowish-pigmented bacterial strain, designated as MQ-18(T), was isolated from a sample of activated sludge collected from a pharmaceutical factory in Zhejiang, China. The strain was characterized through a polyphasic taxonomy approach. 16S rRNA gene sequence analysis demonstrated that strain MQ-18(T) showed high similarities to Piscinibacter defluvii SH-1(T) (99.7 %) and Piscinibacter aquaticus IMCC1728(T) (98.4 %), thereby suggesting that it belongs to the genus Piscinibacter. The DNA-DNA relatedness values of this strain to strains SH-1(T) and IMCC1728(T) were only 35.4 and 33.3 %, respectively. Cells of MQ-18(T) were Gram-negative, aerobic, motile, rod-shaped and non-spore forming. This strain exhibited growth at 25-37 degrees C (optimum: 30 degrees C) in the presence of 0-3.0 % (w/v) NaCl (optimum, 0 % NaCl) and at pH 5.0-8.0 (pH 7.0). The predominant fatty acids were C-12:0 (5.5%), C-16:0 (33.7 %), summed feature 3 (C-16:1 omega 7c and/or C-16:1 omega 6c; 38.5 %), and summed feature 4 (anteiso-C-17:1 B and/or iso C17:1 I; 11.6%). The main quinone type was ubiquinone-8, and the major polyamines were cadaverine and putrescine. The major polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The DNA G+C content was 70.1 mol%. On the basis of its phylogenetic, phenotypic and physiological characteristics, strain MQ-18(T) is considered to represent a novel species of the genus Piscinibacter, for which the name Piscinibacter caeni sp. nov. is proposed. The type strain is MQ-18(T) (CCTCC AB 2017223(T)=JCM 32138(T)).