iTRAQ based characterization of proteomic change in petroleum hydrocarbon-degrading Pseudomonas aeruginosa in different pH conditions.

In this study, a global proteomic change was characterized by iTRAQ analysis and bioinformatics analysis to study the influence by different pH conditions on proteins accumulation when Pseudomonas aeruginosa P6 degraded petroleum hydrocarbons. Compared with the condition of pH 7.2, 228 proteins in pH 5.0 and 93 proteins in pH 8.5 were identified as differentially accumulated proteins. The results further showed that in the condition of pH 5.0, fourteen chemotaxis-related proteins, two uptake-related proteins, two cytochromes, nineteen ABC transporters and five porins were downregulated, while two dioxygenases, five β-oxidation-related proteins and one acyl-CoA metabolism-related protein were upregulated. In the condition of pH 8.5, one fimbrial protein, one aldehyde dehydrogenase, eight ABC transporters and six porins were downregulated, while five terminal oxidation-related proteins, one alcohol dehydrogenase, one β-oxidation-related protein and one acyl-CoA metabolism-related protein were upregulated. The results indicated that in the condition of pH 5.0, chemotaxis and uptake of carbon, terminal oxidation of short-chain alkanes and transmembrane transport which are considered as key cellular processes in biodegradation of petroleum hydrocarbons in P.aeruginosa P6 may be disturbed. While in the condition of pH 8.5, the activity of transmembrane transport may decrease.