Parapedobacter pyrenivorans sp nova, 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 degrees C (optimum, 37 degrees C), pH 6.0-10.0 (optimum, pH 8.5) and 0-4% (w/v) Naa. 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-16:1 omega 7c and/or C-16:1 omega 6c), iSO-C-17:0 3-OH, summed feature 9 (iso-C-17:1 omega 9c and/or 10-methyl C-16:0), anteiso-C-15:0, iSO-C-15:0 3-OH, Ci(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.