Differential protein expression during growth on model and commercial mixtures of naphthenic acids in Pseudomonas fluorescens Pf ‐5

Oil sands mining operations produce vast amounts of oil sands process-affected waters (OSPW) that contain recalcitrant and toxic naphthenic acids (NAs), yet little is known about the mechanisms of NA biodegradation and the enzymes involved. Here, we identified several proteins overexpressed inPseudomonas fluorescens Pf-5 during growth on NAs and included multiple transporters (e.g. ABC transporters), suggesting a cellular protective response from NA toxicity, alongside proteins associated with the fatty acid, lipid, and amino acid metabolism. We postulate thatP. fluorescens Pf-5 is using existing fatty acid catabolic pathways (among others) during NA degradation and these protein targets could be exploited in future biotechnological efforts for OSPW reclamation. AbstractNaphthenic acids (NAs) are carboxylic acids with the formula (CnH2n+ZO2) and are among the most toxic, persistent constituents of oil sands process-affected waters (OSPW), produced during oil sands extraction. Currently, the proteins and mechanisms involved in NA biodegradation are unknown. Using LC-MS/MS shotgun proteomics, we identified proteins overexpressed during the growth ofPseudomonas fluorescens Pf-5 on a model NA (4 ′-n-butylphenyl)-4-butanoic acid (n-BPBA) and commercial NA mixture (Acros). By day 11,>95% ofn-BPBA was degraded. With Acros, a 17% reduction in intensity occurred with 10 –18 carbon compounds of theZ family −2 to −14 (major NA species in this mixture). A total of 554 proteins...
Source: MicrobiologyOpen - Category: Microbiology Authors: Tags: ORIGINAL ARTICLE Source Type: research