Phylogenetic Affiliation of Pseudomonas sp. MO2, a Novel Polyhydroxyalkanoate-Synthesizing Bacterium

Abstract

A bacterium, isolated from wastewater after enrichment with waste canola fryer oil, was found to synthesize 12–20 % of cell dry weight (cdw) medium chain length polyhydroxyalkanoates (mcl-PHAs) using different carbon substrates. On the basis of partial 16S rDNA sequence analysis, this bacterium was first identified as Pseudomonas putida and designated as P. putida strain MO2. However, the full 16S rDNA gene sequence from a whole genome sequence analysis of this strain showed 100 % identity to 16S rDNA of Pseudomonas monteilii SB3101 and Pseudomonas monteilii SB3078. The comparison of the cpn60 gene sequence of Pseudomonas sp. strain MO2 with strains of P. putida, P. aeruginosa, P. fluorescens, P. stutzeri, P. syringae, and P. monteilii indicated that this strain is more closely related to P. monteilii than P. putida type strain KT2440. Based on gene sequence similarity index and phylogenetic analyses, some P. putida strains, which were earlier classified as P. putida, are also more closely related to the P. monteilii cluster. Our analyses show that P. putida is a very diverse group with divergent strains, and many strains of P. putida that cluster with P. monteilii species may need to be reclassified.