Stimulation of 3,4-dichloroaniline mineralization by aniline

Abstract

Mineralization of free and of humus-bound 3,4-dichloroaniline (DCA) [a biodegradative intermediate of phenylamide herbicides] by a Pseudomonas putida strain isolated by analog enrichment was greatly enhanced in the presence of aniline. The addition of aniline to soil that contained 0.2-100 .mu.g DCA/g in free or in humus-bound form increased the mineralization rates of DCA severalfold. Within the concentration ranges tested, absolute mineralization of DCA per unit time was positively correlated with increasing DCA and increasing aniline concentrations. The specific enrichment of microbial populations and the induction of pathways that can co-metabolize DCA are the most plausible explanations for the effect of aniline. The observed phenomenon points to a potential approach for eliminating xenobiotic pollutants from contaminated soils.