title: Synthesis of methylphosphonic acid by marine microbes: a source for methane in the aerobic ocean.
abstract: Relative to the atmosphere, much of the aerobic ocean is supersaturated with methane; however, the source of this important greenhouse gas remains enigmatic. Catabolism of methylphosphonic acid by phosphorus-starved marine microbes, with concomitant release of methane, has been suggested to explain this phenomenon, yet methylphosphonate is not a known natural product, nor has it been detected in natural systems. Further, its synthesis from known natural products would require unknown biochemistry. Here we show that the marine archaeon Nitrosopumilus maritimus encodes a pathway for methylphosphonate biosynthesis and that it produces cell-associated methylphosphonate esters. The abundance of a key gene in this pathway in metagenomic data sets suggests that methylphosphonate biosynthesis is relatively common in marine microbes, providing a plausible explanation for the methane paradox.
authors.affiliation: Institute for Genomic Biology, University of Illinois, Urbana, IL 61801, USA. metcalf@uiuc.edu
authors.forename: William W
authors.initials: WW
authors.lastname: Metcalf
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Griffin
authors.forename: Robert M
authors.initials: RM
authors.lastname: Cicchillo
authors.forename: Jiangtao
authors.initials: J
authors.lastname: Gao
authors.forename: Sarath Chandra
authors.initials: SC
authors.lastname: Janga
authors.forename: Heather A
authors.initials: HA
authors.lastname: Cooke
authors.forename: Benjamin T
authors.initials: BT
authors.lastname: Circello
authors.forename: Bradley S
authors.initials: BS
authors.lastname: Evans
authors.forename: Willm
authors.initials: W
authors.lastname: Martens-Habbena
authors.forename: David A
authors.initials: DA
authors.lastname: Stahl
authors.forename: Wilfred A
authors.initials: WA
authors.lastname: van der Donk
mesh_terms: D000332:Aerobiosis; D059001:Aquatic Organisms / Q000235:genetics / Q000378:metabolism*; D001105:Archaea / Q000235:genetics / Q000378:metabolism*; D019843:Archaeal Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D049308:Dioxygenases / Q000145:classification / Q000235:genetics / Q000378:metabolism; D023061:Gene Order; D054892:Metagenome; D008697:Methane / Q000096:biosynthesis*; D009943:Organophosphorus Compounds / Q000378:metabolism*; D010802:Phylogeny; D012623:Seawater / Q000737:chemistry / Q000382:microbiology
chemical_list: D019843:Archaeal Proteins; D009943:Organophosphorus Compounds; C032627:methylphosphonic acid; D049308:Dioxygenases; D008697:Methane