Towards a systematic understanding of aerobic methylated amine metabolism in the ocean

甲基化胺化合物在海洋中普遍存在，在海洋养分循环和大气化学中起着重要作用。MAs参与气溶胶的形成和由含氮和含硫化合物氧化引起的大气酸度的中和。甲基甲烷被羟基自由基和臭氧氧化后形成一氧化二氮（N2O）和氰化氢（HCN），并成为产甲烷菌产生甲烷（CH4）的前体，从而促进“温室效应”。尽管海洋ma具有全球重要性，但由于缺乏关于这些化合物的来源和汇的数据，对其环境影响进行建模和量化一直受到阻碍。已知微生物利用MAs作为能量和营养来源，因此影响海洋中MAs的浓度，从而影响通过海气界面的通量；然而，这些关键参与者的身份和代谢途径在很大程度上仍然未知。本研究的目的是表征海洋MA利用者的多样性和丰度，并利用模型海洋微生物研究MA代谢途径的酶学和调控。这项研究将验证以下假设：MAs被海洋中专门的甲基营养体（使用单碳（C1）化合物的细菌）用作碳(C)来源，以及多种海洋微生物可以代谢MAs作为氮(N)来源的假设。

Methylated amine compounds (MAs) are ubiquitous in the ocean and play significant roles in marine nutrient cycling and atmospheric chemistry. MAs are involved in the formation of aerosols and neutralization of atmospheric acidity resulting from the oxidation of nitrogen- and sulfur-containing compounds. MAs also contribute to the 'greenhouse effect' by the formation of nitrous oxide (N2O) and hydrogen cyanide (HCN) from their oxidation by hydroxyl radicals and ozone, and by being precursors for methane (CH4) produced by methanogens. Despite the global importance of marine MAs, modelling and quantifying their environmental impacts has been hindered by a paucity of data on the origins and sinks of these compounds. Microorganisms are known to use MAs as sources of energy and nutrients therefore affecting the concentrations of MAs in the ocean and hence fluxes across the air-sea interface; however, the identities of these key players and metabolic pathways remain largely unknown. The objective of this proposed research is to characterize the diversity and abundance of marine MA utilizers and to investigate the enzymology and regulation of MA-metabolizing pathways using model marine microorganisms. This research will test the hypothesis that MAs are used as a carbon (C) source by specialized methylotrophs (bacteria that use one-carbon (C1) compounds) in the ocean, and that diverse marine microorganisms can metabolize MAs as a source of nitrogen (N).