Award: OCE-1155756

Moyer, Co-PI (NSF OCE-1155756, $639,846, 07/12 to 12/17). Project Title - Collaborative research: Ecology of microbial mats at seamount associated Fe-rich hydrothermal vent systems. This project focused on the discovery and characterization of abundant microbial iron mat communities associated with Fe-rich deep-sea hydrothermal vents. Intellectual merit: This study has provided evidence that Zetas that can act as ecosystem engineers. Geochemical analysis confirmed substantial iron fluxes in these systems and showed that O2 concentrations can range from below detection in the microbial mats, to values approximately one-half of seawater saturation. Cultivation efforts at the Mariana backarc Snail vent field (among others), has led to the discovery of Fe-oxidizing microbes, including two novel isolates, can grow on H2 in addition to Fe(II). We have also conducted fine-scale sampling to closely examine microbial mat growth and morphology, community level functional gene analysis and multiple site metagenomics. Broader impacts: A meta-analysis of amplicon sequence data from a variety of marine environments revealed that Zetas have only been found in any abundance at high iron environments. This confirmed their association with the marine iron cycle, and provides further evidence that Fe(II) is their preferred energy source. A postdoctoral researcher, four graduate students, and six undergraduates were supported. Seven publications have resulted from this project and are cited below. In addition, 14 presentations were also made at both national and international scientific meetings. Refs Cited: Hager K. W., H. Fullerton, D. A. Butterfield, and C. L. Moyer. 2017. Community structure of lithotrophically-driven microbial mats from the Mariana Arc and back-arc. Front. Microbiol. 8:1578. doi:10.3389/fmicb.2017.01578. Mori, J. F., J. J. Scott, K. W. Hager, C. L. Moyer, K. Kusel, and D. Emerson. 2017. Physiological and ecological implications of an iron- or hydrogen-oxidizing member of the Zetaproteobacteria, Ghiorsea bivora, gen. nov., sp. nov. ISME J. 11:2624-2636. doi:10.1038/ismej.2017.132. Emerson, D., J. J. Scott, A. Leavitt, E. Fleming, and C. L. Moyer. 2017. In situ estimates of iron-oxidation and accretion rates for iron-oxidizing bacterial mats at Lo'ihi Seamount. Deep Sea Res. Part I Oceanogr. Res. Pap. 126:31-39. doi:10.1016/j.dsr.2017.05.011. Fullerton, H., K. W. Hager, S. M. McAllister, and C. L. Moyer. 2017. Hidden diversity revealed by genome-resolved metagenomics of iron-oxidizing microbial mats from Lo'ihi Seamount, Hawai'i. ISME J. 11:1900-1914. doi:10.1038/ismej.2017.40. Sylvan, J. B., S. D. Wankel, D. E. LaRowe, C. N. Charoenpong, J. A. Huber, C. L. Moyer, and K. J. Edwards. 2017. Evidence for microbial mediation of subseafloor nitrogen redox processes at Loihi Seamount, Hawaii. Geochim. Cosmochim. Acta 198:131-150. doi:10.1016/j.gca.2016.10.029. Fullerton, H., K. W. Hager, and C. L. Moyer. 2015. Draft genome sequence of Mariprofundus ferrooxydans strain JV-1, isolated from Loihi Seamount, Hawaii. Genome Announc. 3(5):e01118-15. doi:10.1128/genomeA.01118-15. Jesser, K. J., H. Fullerton, K. W. Hager, and C. L. Moyer. 2015. Quantitative PCR analysis of functional genes in iron-rich microbial mats at an active hydrothermal vent system (Lo'ihi Seamount, Hawai'i). Appl. Environ. Microbiol. 81:2976-2984. Last Modified: 04/11/2018 Submitted by: Craig L Moyer