QUANTIFICATION OF CATECHOL 2,3-DIOXYGENASE GENE HOMOLOGY AND BENZOATEUTILIZATION IN INTERTIDAL SEDIMENTS

The catechol 2,3-dioxygenase (C23O) gene, xylE, from the TOL plasmid p athway was used to probe naturally occurring bacterial communities in an intertidal microbial mat. Bound probe was quantified by densitometr ic analysis of slot blots using colorimetric detection of hybridizatio n between the probe and total DNA extracts from the sediments. The C23 O gene encodes the key ring-breaking enzyme of the toluene degradation pathway, of which benzoate is an intermediate. Radiotracer experiment s using C-14-benzoate detected benzoate mineralization in these sedime nts, corroborating the presence of both the genetic potential and in s itu activity for this transformation.