Degradation of chlorobenzenes by a strain of Acidovorax avenae isolated from a polluted aquifer.
A subsurface microbial community was isolated from a polluted site of Suquía River (Córdoba-Argentina), acclimated during 15 days in aerobic conditions using 1,2-dichlorobenzene (1,2-DCB) as the sole carbon source. From this acclimated community, we isolated and identified by 16S rDNA analysis a strain of Acidovorax avenae, which was able to perform the complete biodegradation of 1,2-DCB in two days affording stoichiometric amounts of chloride. This pure strain was also tested for biodegradation of chlorobenzene (CB); 1,3-DCB and 1,4-DCB, giving similar results to the experiments using 1,2-DCB. The aromatic-ring-hydroxylating dioxygenase (ARHDO) alpha-subunit gene core, encoding the catalytic site of the large subunit of chlorobenzene dioxygenase, was detected by PCR amplification and confirmed by DNA sequencing. These results suggest that the isolated strain of A. avenae could use a catabolic pathway, via ARHDO system, leading to the formation of chlorocatecols during the first steps of biodegradation, with further chloride release and subsequent paths that showed complete substrate consumption.
Monferrán
Magdalena V
MV
Universidad Nacional de Córdoba-CONICET, Facultad de Ciencias Químicas, Dep. Bioquímica Clínica-CIBICI, Haya de La Torre esq, Medina Allende, Ciudad Universitaria, 5000 Córdoba, Argentina.
Echenique
José R
JR
Wunderlin
Daniel A
DA
D000595:Amino Acid Sequence; D001673:Biodegradation, Environmental; D002722:Chlorobenzenes / Q000378:metabolism*; D042621:Comamonadaceae / Q000235:genetics / Q000502:physiology*; D004269:DNA, Bacterial / Q000032:analysis; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D014881:Water Supply
D002722:Chlorobenzenes; D004269:DNA, Bacterial; C004726:2-dichlorobenzene; C018511:4-dichlorobenzene