Metabolic Fates and Response Strategies of Microorganisms to Aromatic Compounds with Different Structures

Abstract

In this study, the metabolic fates and response strategies of microorganisms to aromatic compounds with different structures (phenol, naphthalene, phenanthrene, and pyrene) were comparatively studied. The results indicated that the phenol (90.9%), naphthalene (81.3%%), phenanthrene (69.5%), pyrene (67.1%) were completely mineralized to CO2 and H2O, and the biotoxicity also has been drastically reduced. The degradation characteristics and toxic effects were closely related to their chemical structure. The microorganisms showed different response strategies to aromatic compounds with different structures. Phenol had a simple structure and low toxicity, the microbial community structure was simple, and the rapid expression of key enzymes enabled it to be rapidly degraded. For the hydrophobic and complex naphthalene, phenanthrene, and pyrene, the more complex the structure, the higher the microbial diversity, the EPS showed different response for the purpose of improving their bioavailability, and the activity of key enzymes was positively correlated with their structural complexity.

Keywords: Aromatic compounds, Chemical structures, Metabolic fates, Response strategies, Microbial community