Biodegradation of Pyridine and Pyridine Derivatives by Soil and Subsurface Microorganisms

Abstract

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 homocyclic 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 interest in the biodegradation of heterocyclic compounds. Hence, we investigated the microbial degradation of pyridine and some of its alkylated 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 conditions and, to a lesser extent, under anaerobic conditions, with nitrate or sulfate serving as electron acceptors. In groundwater polluted with various pyridine derivatives, biodegradation was limited by the absence of oxygen. Therefore, we conclude that, under appropriate conditions, bioremediation is a potentially feasible method for the clean-up of environments contaminated with heterocyclic chemicals and, in particular, pyridine derivatives.