Characterization of a Novel Chlorobenzoate Degrading bacterium: Burkholderia phytofirmans OLGA172, Isolated from a Pristine Environment

Burkholderia phytofirmans OLGA172 is a chlorobenzoate (CBA) degrading bacterium, known to frequently lose the ability to degrade CBA in the lab. OLGA172 carries the complete set of genes for chlorocatechol degradation (an intermediate in CBA metabolism), tfdCDEF, as well as several integrases associated with DNA mobility in proximity to these genes. In this study, putative CBA degradative genes were identified in OLGA172, and an imbalance in regulation between the tfdCDEF and CBA degradative genes identified as a cause for incomplete CBA metabolism in this strain. Additionally, expression of the integrase genes was observed to occur constitutively. The role of this expression was not determined but hypothesized to be related to the phenotypic instability seen in OLGA172. Characterization of the strain was carried out with the aim to determine the ecological niche OLGA172 occupies naturally. Results of characterization are discussed in the context of evolution of the chlorocatechol degradative genes.MAS