Abstract
tmoA and related genes encode the alpha-subunit of the hydroxylase component of the major group (subgroup 1 of subfamily 2) of bacterial multicomponent mono-oxygenase enzyme complexes involved in aerobic benzene, toluene, ethylbenzene and xylene (BTEX) degradation. A PCR-denaturing gradient gel electrophoresis (DGGE) method was developed to assess the diversity of tmoA-like gene sequences in environmental samples using a newly designed moderately degenerate primer set suitable for that purpose. In 35 BTEX-degrading bacterial strains isolated from a hydrocarbon polluted aquifer, tmoA-like genes were only detected in two o-xylene degraders and were identical to the touA gene of Pseudomonas stutzeri OX1. The diversity of tmoA-like genes was examined in DNA extracts from contaminated and non-contaminated subsurface samples at a site containing a BTEX-contaminated groundwater plume. Differences in DGGE patterns were observed between strongly contaminated, less contaminated and non-contaminated samples and between different depths, suggesting that the diversity of tmoA-like genes was determined by environmental conditions including the contamination level. Phylogenetic analysis of the protein sequences deduced from the amplified amplicons showed that the diversity of TmoA-analogues in the environment is larger than suggested from described TmoA-analogues from cultured isolates, which was translated in the DGGE patterns. Although different positions on the DGGE gel can correspond to closely related TmoA-proteins, relationships could be noticed between the position of tmoA-like amplicons in the DGGE profile and the phylogenetic position of the deduced protein sequence.
Original language | English |
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Pages (from-to) | 262-273 |
Journal | FEMS Microbiology Ecology |
Volume | 55 |
Issue number | 2 |
DOIs | |
Publication status | Published - 1 Feb 2006 |
Keywords
- bacteria/classification
- bacterial proteins/genetics
- benzene/metabolism
- benzene derivatives/metabolism
- biodiversity
- dna
- electrophoresis, polyacrylamide gel/methods
- molecular sequence data
- phylogeny
- polymerase chain reaction
- pseudomonas stutzeri/genetics
- sequence analysis, dna
- sequence homology
- soil microbiology
- soil pollutants/metabolism
- toluene/metabolism
- xylenes/metabolism