Degradation of Chlorobenzenes by a strain of Acidovorax avenae Isolated from a Polluted Aquifer.

MONFERRÁN, M. V.; ECHENIQUE, J.R.; WUNDERLIN, D. A.

CHEMOSPHERE

ELSEVIER

Año: 2005 vol. 61 p. 98 - 106

0045-6535

A subsurface microbial community was isolated from a polluted site of Suquý´a River (Co´rdoba—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 identi.ed by 16S rDNA analysis a strain of Acidovorax avenae, which was able to perform the complete biodegradation of 1,2-DCB in two days a.ording 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) a-subunit gene core, encoding the catalytic site of the large subunit of chlorobenzene dioxygenase, was detected by PCR ampli.cation and con.rmed 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 .rst steps of biodegradation, with further chloride release and subsequent paths that showed complete substrate consumption.Acidovorax avenae, which was able to perform the complete biodegradation of 1,2-DCB in two days a.ording 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) a-subunit gene core, encoding the catalytic site of the large subunit of chlorobenzene dioxygenase, was detected by PCR ampli.cation and con.rmed 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 .rst steps of biodegradation, with further chloride release and subsequent paths that showed complete substrate consumption.a-subunit gene core, encoding the catalytic site of the large subunit of chlorobenzene dioxygenase, was detected by PCR ampli.cation and con.rmed 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 .rst steps of biodegradation, with further chloride release and subsequent paths that showed complete substrate consumption.A. avenae could use a catabolic pathway, via ARHDO system, leading to the formation of chlorocatecols during the .rst steps of biodegradation, with further chloride release and subsequent paths that showed complete substrate consumption.