Abstract
Enrichment culture media, which reduced the recovery ratios of residual hexachlorobenzene (200 ppm) to several % within 2 weeks, were prepared after 4 transfers of paddy field soil and PCB-treated flooded soil. Eleven morphologically identical anaerobic microorganisms, which had a reduced residual HCB recovery ratio, were isolated using aerobic agar plates. The isolated microorganisms remarkably reduced the recovery ratio of residual heptachlor but their reduction of endrin, aldrin, and dieldrin was not so remarkable, and had novel morphological and physiological characters, which clearly distinguished these microorganisms from any of the known microorganisms.
