DEGRADATION OF 2,4-DICHLOROPHENOXYACETIC ACID BY MIXED CULTURES OF BACTERIA

We explored the feasibility of using mixed cultures for herbicide degradation, with the ultimate aim of application for effluent treatment. The present study reports on mixed cultures which were developed to grow aerobically with 2,4-dichlorophenoxyacetic acid (2,4-D) as the sole carbon substrate. Degradation of 2,4-D was verified by HPLC and UV-spectroscopic analysis of the residual 2,4-D concentration in the test cultures. Cultures that were initially developed with 2,4-D also grew readily with glucose, but the degradation of 2,4-D was effectively prevented under mixed substrate conditions. Major intermediates or metabolites resulting from 2,4-D degradation were not detected with the HPLC methodology except 2,4-dichlorophenol which appeared to accumulate transiently in the growth medium.