Superfund Research Program
Ecology and Diversity of BTEX Degrading Bacteria in Bioreactors and Aquifers
Project Leader: James M. Tiedje
Grant Number: P42ES004911
Funding Period: 1995 - 2000
Project investigators have isolated more than 20 strains of an anaerobic (denitrifying) toluene-degrading family of bacteria. These have now been fully characterized and described as three species of the novel genus Azoarcus. Researchers have developed DNA based probes for this family and have successfully used them in the field to detect this organism in a gasoline contaminated well to which nitrate was added to stimulated anaerobic toluene removal. The last phase of this project was evaluation of the pattern of bacterial biodegradation capacity relative to the phylogenetic tree of life. The data supports the hypothesis that biodegradation, at least among the so far cultured groups of bacteria, is confined to four divisions of bacteria. Hence, biodegradation traits, which are often on transmissible plasmids, have not spread widely within the microbial world. They have, however, spread widely within these four bacterial lineages. This work has led to the development of a microbial Biodegradation Strain Database (BSD), www.cme.msu.edu/BSD. A searchable version on a dbms platform is to be available approximately July 1, 2000.