DIVERSITY OF ANAEROBIC MICROBIAL PROCESSES IN CHLOROBENZOATE DEGRADATION - NITRATE, IRON, SULFATE AND CARBONATE AS ELECTRON ACCEPTORS

The utilization of monochlorobenzoate isomers (2-, 3- and 4-chlorobenz oate) by anaerobic microbial consortia in River Nile sediments was sys tematically evaluated under denitrifying, Fe-reducing, sulfidogenic an d methanogenic conditions. Loss of all three chlorobenzoates was noted in denitrifying cultures; furthermore, the initial utilization of chl orobenzoates was fastest under denitrifying conditions. Loss of 3-chlo robenzoate was seen under all four reducing conditions and the degrada tion of chlorobenzoates was coupled stoichiometrically to NO3- loss, F e2+ production SO42- loss or CH4 production, indicating that the chlor obenzoates were oxidized to CO2. To our knowledge, this is the first o bservation of halogenated aromatic degradation coupled to Fe reduction .