Fig. 5

Artistic illustration of primary functions observed for the Bering Strait microbiome as a system in response to additions of algal organic matter (OM). The initial microbiome (Day 0) had a higher abundance of peptides correlating to outer membrane proteins, such as transporters and receptors, and enzymes involved in the C1 metabolic pathway. At day 0, lysed native algal organic matter was added to the incubation experiments yeilding a significant increase in peptides related to cellular growth within the microbiome observed including translation, ATP generation, and glycolysis. By day 6, significant increases in peptides associated with ABC transporters, the uptake and utilization of a range of nitrogen sources, and intracellular nitrogen recycling were identified. These pathways were inherently linked with increased abundances of peptides involved in the TCA cycle, which included increases in metal-binding proteins, GS-GOGAT pathway, and vitamin production. ADP adenosine diphosphate, ATP adenosine triphosphate, AKG alphaketogluterate, LSU large ribosomal subunit, OAA oxaloacetate, GS glutamine synthetase, GOGAT glutamine oxoglutarate aminotransferase (Glutamate synthase), SSU small ribosomal subunit, RBP ribosomal binding proteins, THF tetrahydrofolate