DI-ALLATE DEGRADATION BY AN EPTC-DEGRADING RHODOCOCCUS, AND IN EPTC-TREATED SOIL

A Rhodococcus soil isolate TEI, known to degrade EPTC, degraded di-allate [S(2,3-dichloroallyl) diisopropylthiocarbamate] but only in the presence of a cometabolite. More di-allate was degraded by TEI in basal salts medium supplemented with yeast extract or nutrient broth than with glucose or glycerol. Also unlike EPTC, di-allate could not serve as the sole source of carbon for growth of the bacterium. The degradation products of di-allate may have an inhibitory effect on the continued growth of TEI. A mutant of TEI (TE3) lacking a plasmid associated with EPTC degradation was also unable to degrade di-allate. Similar results were found with tri-allate. Soils treated in the laboratory with EPTC contained an adapted microflora which could degrade di-allate. Di-allate adapted soils, however, did not show enhanced EPTC degradation.