BIODEGRADATION OF PYRIDINE AND PYRIDINE-DERIVATIVES BY SOIL AND SUBSURFACE MICROORGANISMS

Large amounts of aromatic compounds are produced by various industries and two thirds of these are heterocyclic chemicals. Compared with the extensive information available on microbial degradation of homocycli c aromatic compounds, relatively little is known on the transformation and biodegradation of heterocyclic chemicals in soil. Recent concerns about the persistence of hazardous pollutants have led to a renewed i nterest in the biodegradation of heterocyclic compounds. Hence, we inv estigated the microbial degradation of pyridine and some of its alkyla ted derivatives under aerobic and anaerobic conditions in groundwater, subsurface sediment, and soil. Results of the investigation revealed that these compounds were degraded predominantly under aerobic conditi ons and, to a lesser extent, under anaerobic conditions, with nitrate or sulfate serving as electron accepters. In groundwater polluted with various pyridine derivatives, biodegradation was limited by the absen ce of oxygen. Therefore, we conclude that, under appropriate condition s, bioremediation is a potentially feasible method for the clean-up of environments contaminated with heterocyclic chemicals and, in particu lar, pyridine derivatives.