Microdiversity of phenol hydroxylase genes among phenol-degrading isolates of Alcaligenes sp. from an activated sludge system.
Enterobacterial repetitive intergenic consensus (ERIC)-PCR fingerprinting classified 97 phenol-degrading isolates with identical amplified ribosomal DNA restriction analysis (ARDRA) patterns into six genotypic groups. The 16S rRNA gene of the representative isolate of each group had higher than 99.47% common identity with each other and higher than 98% identity with the type strain of Alcaligenes faecalis. PCR-TGGE (temperature gradient gel electrophoresis) analysis of the genes of the largest subunit of the multi-component phenol hydroxylase (LmPH) in each isolate followed with sequencing showed that isolates within each ERIC-PCR group had identical LmPH gene sequences. Among the six different ERIC-PCR groups, two were found to harbor two different LmPH genes encoding low- and high-Ks (affinity constants) phenol hydroxylases, and the low-Ks type LmPH was identical in sequence with one predominant LmPH of the parental activated sludge. Three ERIC-PCR groups had only the high-Ks type and one had no sequence similar to the known LmPHs. Our work suggests that there is no correlation between the phylogenetic groupings of phenol-degrading bacteria and their LmPH genotypes possibly due to extensive horizontal gene transfer of this functional gene.
Zhang
Xueli
X
Laboratory of Molecular Microbial Ecology and Ecogenomics, College of Life Science and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
Gao
Pingping
P
Chao
Qunfang
Q
Wang
Linghua
L
Senior
Eric
E
Zhao
Liping
L
D000421:Alcaligenes / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000032:analysis; D005798:Genes, Bacterial; D020459:Genes, rRNA; D014644:Genetic Variation; D006899:Mixed Function Oxygenases / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D009693:Nucleic Acid Hybridization; D019800:Phenol / Q000378:metabolism*; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012722:Sewage / Q000382:microbiology*
D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D012722:Sewage; D019800:Phenol; D006899:Mixed Function Oxygenases; C022336:phenol 2-monooxygenase