Parapedobacter pyrenivorans sp. nov., isolated from a pyrene-degrading microbial enrichment, and emended description of the genus Parapedobacter

A novel pyrene-degrading, Gram-negative bacterium, designated strain P-4^T, was isolated from a polycyclic aromatic hydrocarbon-degrading enrichment of polluted soils from a coking chemical plant. Cells of strain P-4^T were non-motile rods. Strain P-4^T grew at 15–45 °C (optimum, 37 °C), pH 6.0–10.0 (optimum, pH 8.5) and 0–4 % (w/v) NaCl. Analysis of the 16S rRNA gene sequence showed that strain P-4^T was related phylogenetically to members of the genus Parapedobacter, with sequence similarity of 93.7–95.1 %. The cellular fatty acids of strain P-4^T were iso-C_15 : 0, summed feature 3 (C_16 : 1ω7c and/or C_16 : 1ω6c), iso-C_17 : 0 3-OH, summed feature 9 (iso-C_17 : 1ω9c and/or 10-methyl C_16 : 0 ), anteiso-C_15 : 0, iso-C_15 : 0 3-OH, C_16 : 0, iso-C_15 : 1 G, C_16 : 0 3-OH and C_17 : 0 2-OH. Cells contained menaquinone 7 as the major quinone. The polyamine of strain P-4^T was homospermidine, and the main polar lipids were phosphatidylethanolamine and a sphingolipid. The G+C content of the DNA was 45.4 mol%. Strain P-4^T showed a range of phenotypic characteristics that differentiated it from previously recognized Parapedobacter species, particularly its ability to use pyrene as a sole carbon source for growth and its alkaline optimal pH for growth (pH 8.5). On the basis of these results, it is concluded that strain P-4^T represents a novel species of the genus Parapedobacter, for which the name Parapedobacter pyrenivorans (type strain P-4^T = NBRC 109113^T = CGMCC 1.12195^T) is proposed. An emended description of the genus Parapedobacter is also provided.