Gut Microbial Profiles in Nereis succinea and Their Contribution to the Degradation of Organic Pollutants.

Gut microbiota of wildlife are usually exposed to and involved in degrading environmental pollutants, yet their biodegrading capacity remains largely unexplored. Here, we analyzed gut microbial profiles of a marine benthic polychaete, Nereis succinea, and elaborated the capacity of gut microbiota in degrading various organic pollutants, including polycyclic aromatic hydrocarbons, pesticides, phenols, and synthetic musks. High-throughput sequencing analysis revealed that the structures of microbial communities, including bacteria, fungi, and archaea, varied along the gut, manifesting distinct structural features in the fore-, mid-, and hindgut regions. Community-level physiological profiles and the capacity of gut microbiota in degrading the pollutants showed profound gut region and oxygen dependent features. In general, anaerobes were more active in degrading the pollutants, and those in the midgut presented the maximum degrading potential. Degradation capability of the gut microbiota was further quantitatively validated in an in vitro culture system using chlorpyrifos and malathion as representative compounds. Our results demonstrated a potential impact of gut microbiota in wildlife on the fate of organic pollutants in the ecosystem, which calls for further research on the influences of gut microbiota on biotransformation and bioaccumulation of xenobiotics in organisms.