Identification of genes coding for hydrolytic dehalogenation in the metagenome derived from a denitrifying 4-chlorobenzoate degrading consortium.
A metagenomic approach was taken to investigate the genetic basis for the ability of an anaerobic consortium to grow on either 4-chlorobenzoate or 4-bromobenzoate under denitrifying conditions. Degenerate PCR primers were designed for the family of 4-chlorobenzoyl-CoA dehalogenase genes. The primers were utilized to screen a metagenome library and two overlapping clones were identified which yield a PCR product. The complete sequence of one metagenome clone was determined and genes encoding 4-chlorobenzoyl-CoA ligase (FcbA) and 4-chlorobenzoyl-CoA dehalogenase (FcbB) were identified. Analysis of the ORFs present in the nucleotide sequence suggests that the metagenome clone originated from an uncultured denitrifying microorganism belonging to the Betaproteobacteria. Interestingly, unlike similar gene clusters reported in aerobes, a gene encoding 4-hydroxybenzoyl-CoA thioesterase was not present in the gene cluster. This suggests that 4-hydroxybenzoyl-CoA is further degraded via the anaerobic reduction pathway in the corresponding microorganism instead of through thioester hydrolysis to yield 4-hydroxybenzoate.
Chae
Jong-Chan
JC
Biotechnology Center for Agriculture and the Environment, School of Environmental and Biological Sciences, Rutgers University, New Brunswick, NJ 08901-8520, USA. chae@aesop.rutgers.edu
Song
Bongkeun
B
Zylstra
Gerben J
GJ
D000693:Anaerobiosis; D001419:Bacteria / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D020562:Betaproteobacteria / Q000235:genetics / Q000302:isolation & purification; D002723:Chlorobenzoates / Q000378:metabolism*; D002874:Chromosome Mapping; D003360:Cosmids / Q000235:genetics; D017931:DNA Primers / Q000032:analysis / Q000235:genetics; D005798:Genes, Bacterial; D016680:Genome, Bacterial; D015698:Genomic Library; D019015:Geologic Sediments / Q000382:microbiology; D054879:Halogenation; D006867:Hydrolases / Q000235:genetics*; D008969:Molecular Sequence Data; D009566:Nitrates / Q000378:metabolism*; D010802:Phylogeny; D017422:Sequence Analysis, DNA
D001426:Bacterial Proteins; D002723:Chlorobenzoates; D017931:DNA Primers; D009566:Nitrates; D006867:Hydrolases; C084333:4-chlorobenzoyl coenzyme A dehalogenase; C040768:4-chlorobenzoic acid