DIVERSITY AND ACTIVITY OF CHEMOAUTOTROPHIC BACTERIA IN THE APHOTIC WATERS OF THE SUBTROPICAL NORTH PACIFIC OCEAN
Recent genetic and biogeochemical studies suggest metabolically diverse microbial assemblages inhabiting the meso- and bathypelagic waters of the open ocean. Among the diverse metabolic processes, chemoautotrophy may constitute an important pathway of microbial carbon transformation in the deep sea. In this study, we examined the presence and diversity of microorganisms containing cbbM genes that encode a component of the ribulose-1 5-bisphosphate carboxylase-oxygenase (RuBisCO) enzyme utilized in the Calvin Benson Bassham cycle. Bacterial cbbM genes were PCR amplified, cloned, and sequenced from nucleic acid samples collected at Station ALOHA in the North Pacific Subtropical Gyre. We identified cbbM genes belonging to the both Gammaproteobacteria and Deltaproteobacteria (including members of the SAR324 clade) in the mesopelagic waters at Station ALOHA. To evaluate potential energy sources utilized by these microorganisms, we conducted experiments where we examined how the addition of a reduced sulfur substrate (thiosulfate) influenced rates of autotrophic carbon fixation and diversity of cbbM containing bacteria. Our results shed light on the potential metabolic strategies employed by microbial assemblages in the dark ocean.
Thomas, S. E., University of Hawaii at Manoa, USA, firstname.lastname@example.org
Church, M. J., University of Hawaii at Manoa, USA, email@example.com
Time: 16:00 - 18:00
Location: Poster/Exhibit Hall
Presentation is given by student: Yes