Isolation and characterization of a thermotolerant bacterium Ralstonia sp. strain PHS1 that degrades benzene, toluene, ethylbenzene, and o-xylene.
A thermotolerant bacterium, designated as PHS1, was isolated from a hot spring in Pohang, Korea, on the basis of its ability to grow on benzene, toluene, ethylbenzene, and xylenes (BTEX) as a sole carbon source. Strain PHS1 is a gram-negative, rod-shaped aerobe and grows optimally at 42 degrees C and pH 7.2. According to 16 S rDNA analysis, strain PHS1 showed highest similarity to Ralstonia eutropha (previously named Alcaligenes eutrophus). Unlike its closest known Ralstonia species, however, strain PHS1 was able to utilize toluene, ethylbenzene, o-xylene, and both m- and o-cresol. The degradation of o-xylene by strain PHS1 is particularly important, since o-xylene is a compound of considerable environmental interest, owing to its recalcitrance; and very few microorganisms have been reported to utilize o-xylene as a sole carbon source. It was found that strain PHS1 transformed o-xylene to 2,3-dimethylphenol through direct oxygenation of the aromatic ring. The unique properties of strain PHS1, such as thermotolerance and the ability to degrade o-xylene, may have important implications for the treatment of BTEX-contaminated industrial effluents.
Lee
S K
SK
Department of Chemical Engineering, Pohang University of Science and Technology, Hyoja-Dong, Korea. sblee@postech.ac.kr
Lee
S B
SB
D001554:Benzene / Q000378:metabolism*; D001555:Benzene Derivatives / Q000378:metabolism*; D020118:Cupriavidus necator / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000737:chemistry / Q000235:genetics; D014050:Toluene / Q000378:metabolism*; D014992:Xylenes / Q000378:metabolism*
D001555:Benzene Derivatives; D012336:RNA, Ribosomal, 16S; D014992:Xylenes; D014050:Toluene; D001554:Benzene; C004912:ethylbenzene; C026114:2-xylene