@article{0c0a96b4abbb41c3b9f5a86fb5d73fd2,
title = "Microbial Methane From Methylphosphonate Isotopically Records Source",
abstract = "Methane is a potent greenhouse gas commonly supersaturated in the oxic surfaces waters of oceans and lakes, yet canonical microbial methanogens are obligate anaerobes. One proposed methane production pathway involves microbial degradation of methylphosphonate (MPn), which can proceed in the presence of oxygen. Directly tracing dissolved methane to its source in oxic waters, however, remains a challenge. To address this knowledge gap, we quantified the carbon isotopic fractionation between substrate MPn and product methane (1.3‰) in lab experiments, which was 1 to 2 orders of magnitude smaller than canonical pathways of microbial methanogenesis (20 to 100‰). Together, these results indicated that microbial catabolism of MPn is a source of methane in surface oceans and lake waters, but to differentiate sources of MPn in nature a further accounting of all sources is necessary. Methane from this pathway must be considered in constraining the marine carbon cycle and methane budget.",
keywords = "C-P lyase, carbon isotopes, marine methane paradox, methylphosphonate, surface ocean",
author = "L. Taenzer and Carini, {P. C.} and Masterson, {A. M.} and B. Bourque and Gaube, {J. H.} and Leavitt, {W. D.}",
note = "Funding Information: General: We thank Alec Cobban and Beverly Chiu for lab assistance and Alex Bradley, Doug Rumble III, Ed Young, and Ann Pearson for discussion or comments on an earlier draft. Funding: Financial support from the Vice‐Provost for Research Seed grant and the Walter and Constance Burke Fund at Dartmouth College (W. D. L.), the Simons Foundation (W. D. L.), and NASA NH Space grant NNX15AH79. Support for P. C. and B. B. came from startup funds provided to P. C. from the University of Arizona's Technology and Research Initiative Fund (Water, Environmental, and Energy Solutions initiative), seed grants from the Center for Environmentally Sustainable Mining and the University of Arizona College of Agriculture and Life Sciences. Author contributions: W. D. L. and P. C. initiated the project; L. T., J. G., P. C., B. B., and W. D. L. designed the experiments; L. T., J. G., and B. B. performed the experiments; L. T. and A. M. performed analyses; and L. T., P. C., and W. D. L. wrote the manuscript. All authors edited the manuscript. Competing interests: The authors declare no competing interests. Data and materials availability: All data are permanently archived on FigShare (10.6084/m9.figshare.10325183). Funding Information: General: We thank Alec Cobban and Beverly Chiu for lab assistance and Alex Bradley, Doug Rumble III, Ed Young, and Ann Pearson for discussion or comments on an earlier draft. Funding: Financial support from the Vice-Provost for Research Seed grant and the Walter and Constance Burke Fund at Dartmouth College (W. D. L.), the Simons Foundation (W. D. L.), and NASA NH Space grant NNX15AH79. Support for P. C. and B. B. came from startup funds provided to P. C. from the University of Arizona's Technology and Research Initiative Fund (Water, Environmental, and Energy Solutions initiative), seed grants from the Center for Environmentally Sustainable Mining and the University of Arizona College of Agriculture and Life Sciences. Author contributions: W. D. L. and P. C. initiated the project; L. T., J. G., P. C., B. B., and W. D. L. designed the experiments; L. T., J. G., and B. B. performed the experiments; L. T. and A. M. performed analyses; and L. T., P. C., and W. D. L. wrote the manuscript. All authors edited the manuscript. Competing interests: The authors declare no competing interests. Data and materials availability: All data are permanently archived on FigShare (10.6084/m9.figshare.10325183). Publisher Copyright: {\textcopyright} 2020. American Geophysical Union. All Rights Reserved.",
year = "2020",
month = jan,
day = "16",
doi = "10.1029/2019GL085872",
language = "English (US)",
volume = "47",
journal = "Geophysical Research Letters",
issn = "0094-8276",
publisher = "American Geophysical Union",
number = "1",
}