S53: Polycyclic aromatic hydrocarbons degradation network in Mycobacterium vanbaalenii PYR-1

Polycyclic Aromatic Hydrocarbons Degradation Network in Mycobacterium vanbaalenii PYR-1 Carl E. Cerniglia, Ohgew Kweon, and Seong-Jae Kim Division of Microbiology, National Center for Toxicological Research/US FDA, Jefferson, AR 72079 carl.cerniglia@fda.hhs.gov Recently, we investigated a metabolic network (MN) from Mycobacterium vanbaalenii PYR-1 for polycyclic aromatic hydrocarbons (PAHs) from the perspective of structure, behavior, and evolution. Based on the omics data integrated from proteomic, metabolic, biochemical, physiological, and genomic information, we reconstructed an experiment-based system-level PAH-MN. The structure of PAH-MN, with 183 metabolic compounds and 224 chemical reactions, has a typical scale-free nature. The behavior and evolution of the PAH-MN reveals a hierarchical modularity with funnel effects in structure/function and intimate association with evolutionary modules of the functional modules, which are the ring cleavage process (RCP), side chain process (SCP), and central aromatic process (CAP). In addition, the combination of "forward genetics" and proteomics approaches of mutant defective in nidA gene responsible for the initial pyrene ring hydroxylation showed that the PAH-MN is robust to such a genetic perturbation. The robustness seems to be mainly related to functional redundancy, which is linked to gene redundancy. Since PAHs are ubiquitous in the environment, generally recalcitrant and shown to be toxic, mutagenic and carcinogenic in higher organisms, our study advances fundamental knowledge in the microbial degradation of PAHs for bioremediation applications.