Proteomic Characterization of the Pseudomonas sp. Strain phDV1 Response to Monocyclic Aromatic Compounds

The degradation of aromatic compounds comprises an important step in the removal of pollutants and re‐utilization of plastics and other non‐biological polymers. Here we set out to study Pseudomonas sp. strain phDV1, a gram‐negative bacterium that was selected for its ability to degrade aromatic compounds. In order to understand how the aromatic compounds and their degradation products are reintroduced in the metabolism of the bacteria and the systematic/metabolic response of the bacterium to the new carbon source, the proteome of this strain was analysed in the presence of succinate, phenol and o‐, m‐, p‐cresol as sole carbon source. We then applied label‐free quantitative proteomics to monitor overall proteome remodeling during metabolic adaptation to different carbon sources. As a reference proteome, we grew the bacteria in succinate and then compared the respective proteomes of bacteria grown on phenol and different cresols. In total, we identified 2295 proteins; 1908 proteins were used for quantification between different growth conditions. We found that 76, 109, 154 and 160 proteins were significantly differentially expressed in cells were grown in phenol, o‐, m‐ and p‐cresol‐containing medium, respectively. The carbon source affected the synthesis of enzymes related to aromatic compound degradation, and in particular, the enzyme involved in the meta‐pathway of monocyclic aromatic compounds degradation. In addition, proteins involved in the production of polyhydroxyalkanoate (PHA), an attractive biomaterial, showed higher abundance in the presence of monocyclic aromatic compounds. The results provide for the first time comprehensive information on proteome response of this strain to monocyclic aromatic compounds