ABSTRACT
Pseudomonas cichorii is divided into two subclades based on the 16S ribosomal RNA gene sequence and core genome multilocus sequence typing. It was shown that subclade 2 strains utilize d-tartrate as a sole carbon source, whereas subclade 1 strains do not. Draft genome sequencing was performed with P. cichorii strains to identify d-tartrate utilization genes. By genome comparative and homology search studies, an â¼7.1-kb region was identified to be involved in d-tartrate utilization. The region is subclade 2 specific, and contains tarD and dctA genes, which encode a putative enzyme and transporter of d-tartrate, respectively. When the region was introduced into subclade 1 strains, the transformants were able to utilize d-tartrate. Partial fragments of tarD and dctA were amplified from all subclade 2 strains tested in this study by PCR using gene-specific primers, but not from subclade 1 strains. This is the first report on the genetic analysis of biochemical characteristics corresponding to a specific phylogenetic group in P. cichorii.