A number of pesticides having a nitro group are extensively used as insecticides or herbicides. The representatives of the pesticides are fenitrothion, CNP, and others. It has been shown that these pesticides are enzymatically reduced to the corresponding amino derivatives in rumen fluid, in soils, in insects, and in fishes, birds, and mammals. Since the resulting amino derivatives are inactive as pesticides, the enzymic reduction is regarded as a pathway of detoxication. On the other hand, since amino CNP has been shown to form a complex with soil constituents, the enzymic reduction is regarded as a pathway of persistence in soils. Hence, it is important to clarify the functions of soil enzymes catalyzing the reduction.
The present work deals with some properties of a crude enzyme with a nitro groupreducing activity. The enzyme was produced by a microorganism isolated from the soil of paddy fields in Shimane Pref.