Characteristics of the whole cell fatty acid profiles of Pseudomonas corrugata

The fatty acid methyl ester (FAME) profiles of eighty strains of Pseudomonas corrugata from different geographic origins have been studied. Gas chromatographic profiles were obtained. The use of hexane/methyl-tert butyl ether (MTBE) (1:1) for the extractions improves the yield of hydroxy-FAMEs used to identify P. corrugata as compared to hexane alone. The analysis of the extracts with hexane/MTBE showed that many strains do not have the characteristic FAMEs of P. corrugata (3-hydroxydodecenoic acid, 3-hydroxytetradecanoic acid, 3-hydroxyhexadecanoic acid and two unknown additional fatty acids). These differences among strains seemed to be related to bacterial dissociation, associated with changes in morphological aspect of the colonies due to subculture. The comparison of profiles of wrinkled and smooth colonies isolated from ten strains confirmed the differences among those in specific FAMEs. Therefore, the FAME profiles are a useful tool for the identification of P. corrugata when the bacteria have not been subcultured in vitro for a long time. Multivariate analyses of data showed that four clusters can be observed supporting the heterogeneity of the strains of P. corrugata.