Quantification of methylphosphonate associated to suspended material at Station ALOHA

Methylphosphonate (MPn) metabolism has been proposed to be an aerobic source of methane in surface oceanic waters. Previous work by Daniela del Valle, C-MORE post-doctoral fellow in the laboratory of Prof. David Karl, has shown that even though microbes are able produce methane from dissolved MPn in the ocean, this process is not a significant source of methane at Station ALOHA. However, this work pointed to particle-associated MPn as a potentially significant source of methane in this system. Prof. William Metcalf and collaborators recently reported a biosynthetic pathway for MPn which is relatively common in marine microbes, and they hypothesized that cellular MPn is linked to an exopolysaccharide. Currently, these two lab groups – Karl and Metcalf – are working in collaboration to quantify the amount of MPn in suspended and sedimenting material in order to look further into the role of MPn as a source of methane in surface waters of the North Pacific Subtropical Gyre.