Abstract
Strain F11T, a phenanthrene-degrading bacterium, was isolated from a petroleum residue treatment system, and classified under the genus Rhizobium based on the similarity analysis of its 16S rRNA and recA gene sequences. Strain F11T falls into the same phylogenetic clade with Rhizobium oryzae Alt 505T (96.8% 16S rRNA gene sequence similarity) and Rhizobium pseudoryzae J34A-127T (96.2%). Major cellular fatty acids of strain F11T are C16:0 (6.24%) and summed feature 8 (C18:1ω7c and/or C18:1ω6c, 76.59%), which are also the major fatty acids of R. oryzae Alt 505T and R. pseudoryzae J34A-127T. The DNA G+C content of strain F11T was 59.3±0.4 mol%. Based on the phylogenetic analysis as well as biochemical and physiological characteristics, strain F11T could be separated from all recognized Rhizobium species. Strain F11T (=DSM 21882T =CCTCC AB 209029T) was considered to be representative of a novel species of Rhizobium, for which the name Rhizobium phenanthrenilyticum sp. nov. is proposed.
