The bphC gene-encoded 2,3-dihydroxybiphenyl-1,2-dioxygenase is involved in complete degradation of dibenzofuran by the biphenyl-degrading bacterium Ralstonia sp. SBUG 290

摘要: ABSTRACT J. WESCHE, E. HAMMER, D. BECHER, G. BURCHHARDT AND F. SCHAUER. 2004. Aims: Biphenyl-degrading bacteria are able to metabolize dibenzofuran via lateral dioxygenation and meta-cleavageof the dihydroxylated produced. This degradation was considered be incomplete becauseaccumulation of a yellow-orange ring-cleavage product observed. In this study, we want characterize the1,2-dihydroxydibenzofuran cleaving enzyme which is involved in bacteriumRalstonia sp. SBUG 290.Methods Results: strain, complete observed after cultivation onbiphenyl. The shows wide substrate utilization spectrum, including 1,2-dihydroxydibenzofuran,2,3-dihydroxybiphenyl, 1,2-dihydroxynaphthalene, 3- 4-methylcatechol catechol. MALDI-TOF analysisof protein revealed strong homology bphC gene products. We therefore cloned 3AE2 kb DNA fragmentcontaining Ralstonia 290. deduced amino acid sequence identical thatof corresponding Pseudomonas KKS102. expressed Escherichia coli themeta-fission activity detected using either 2,3-dihydroxybiphenyl or 1,2-dihydroxydibenzofuran as substrate.Conclusions: These results demonstrate that by biphenyl degraders canoccur initial oxidation steps catalysed products encoded bph-operon. ring fission of1,2-dihydroxydibenzofuran BphC. Differences found metabolism ofdibenzofuran among degrading assumed caused different specificities ofBphD.Significance Impact Study: study for first time thebph-operon mineralization bacteria.Keywords: biphenyl, bphC, degradation, dibenzofuran, meta-cleavage,