BENSULFURON-METHYL - MIXED CULTURE MICROBIAL-DEGRADATION MAINTENANCE

In nature the biodegradation of xenobiotic compounds occurs through co -metabolism processes by microbial associations. The in vitro study of these metabolic processes entails the use of mixed microbial cultures , in which it is difficult to maintain degradative activity over time. We have set up appropriate working conditions to maintain, in methano genic conditions, mixed cultures actively degrading bensulfuron-methyl . Initially the degrading activity of microbial cultures growing on tw o different media was comparable. Microscope observations of the mixed cultures revealed the presence of methanobacteria; moreover in medium MB it was found that the degradative activity of the mixture graduall y diminished with time, the number of methanobacteria also diminishing and finally disappearing. On the contrary, in the M9 MOD medium the d egradative activity remained stable.