Exploring the ocean microbiome: quantified cobalamin production in pelagic bacteria using liquid chromatography and mass spectrometry

Cobalamin, also known as Vitamin B 12 , is an essential part of life. It plays a crucial role in the \nocean, regulating the metabolic activities of oceanic microbes, which in turn play dynamic roles in carbon \ncycles and subsequent atmospheric regulation. This research quantifies cobalamin production in two \nspecies of bacteria under high and low carbon environments, and in environments enriched with two \ncompounds that may originate from other microbial community members and indicate cobalamin stress. \nUsing liquid chromatography and mass spectrometry, this research shows that for most bioavailable \ncobalamin, both R. pomeroyi DSS-3 and Sulfitobacter sp. SA11 produce more but statistically \ninsignificant cobalamin molecules per cell when grown in high carbon environments, as opposed to when \ngrown in carbon starved conditions. When bacteria were grown in enriched environments, overall \ncobalamin production was unaffected by stress signaling compounds, although adenosylcobalamin \nshowed significant change in production. Overall, the figures were statistically inconclusive due to small \nsample size and high intra-sample variation. However, these findings lay groundwork for further research. \nAn important symbiosis involving cobalamin between primary producers and subsections of bacteria and \narchaea has recently been the subject of metabolomics and proteomics research. The results from this \npaper provide valuable data for more analysis in this area, by supplying precedent for growing organisms \nin diluted Seawater Tryptone, and quantitative values of cobalamin production in normal conditions for \nuse in cobalamin models. The findings of this paper highlight both the importance of cobalamin in the \nocean microbiome, and the complexity of the microbial interactions in the ocean.