Organic matter degradation by microbial communities in freshwater and marine systems.

摘要

Organic matter in freshwater and marine systems exists in many of sizes and structures. It is introduced into these systems by autochthonous production or allochthonous input via groundwater, terrestrial run-off, and estuarine mixing. Organic matter is an important source of organic carbon and nutrients to the heterotrophic microbial community, but microbial communities must use extracellular enzymes to degrade substrates and begin cycling the organic matter. Freshwater and marine systems have different microbial communities and capabilities for hydrolyzing organic substrates. We investigated microbial community activities of two rivers in North Carolina, the Neuse and Tar-Pamlico Rivers, at several sites for more than a year to better understand how seasonal and spatial gradients affected organic matter processing. We also investigated community activities at three locations in the coastal North Atlantic over five days in late fall, observing if patterns of degradation might change over small spatial scales in a coastal marine settings.