Methylamine as a nitrogen source for microorganisms from a coastal marine environment

Abstract

Nitrogen is a key limiting resource for biomass production in the marine environment. Methylated amines, released from the degradation of osmolytes, could provide a nitrogen source for marine microbes. Thus far, studies in aquatic habitats on the utilization of methylamine, the simplest methylated amine, have mainly focussed on the fate of the carbon from this compound. Various groups of methylotrophs, microorganisms that can grow on one-carbon compounds, use methylamine as a carbon source. Non-methylotrophic microorganisms may also utilize methylamine as a nitrogen source, but little is known about their diversity, especially in the marine environment. In this proof-of-concept study, stable isotope probing (SIP) was used to identify microorganisms from a coastal environment that assimilate nitrogen from methylamine. SIP experiments using N methylamine combined with metagenomics and metaproteomics facilitated identification of active methylamine-utilizing Alpha- and Gammaproteobacteria. The draft genomes of two methylamine utilizers were obtained and their metabolism with respect to methylamine was examined. Both bacteria identified in these SIP experiments used the γ-glutamyl-methylamide pathway, found in both methylotrophs and non-methylotrophs, to metabolize methylamine. The utilization of N methylamine also led to the release of N ammonium that was used as nitrogen source by other microorganisms not directly using methylamine.

Aliphatic amines at the Cape Verde Atmospheric Observatory: Abundance, origins and sea-air fluxes

“…In addition, marine metagenomics data-mining has identified the presence of genes encoding the production of trimethylamine from nitrogen osmolytes in the open ocean (Jameson et al, 2016). The methylated amines, mono-di-and trimethylamine (MMA, DMA and TMA, respectively), can provide a source of carbon and nitrogen for marine microorganisms (Taubert et al, 2017). Recent studies show that heterotrophic bacteria utilize methylamines (specifically TMA) as a supplementary energy source (Lidbury et al, 2015b).…”

Transcriptional regulation of ectoine catabolism in response to multiple metabolic and environmental cues

“…Finally, the tetrahydropyrimidines ectoine and hydroxyectoine contain two nitrogen atoms (Fig. 1), and thus are particularly valuable compounds in nutrientdeprived ecosystems (Lidbury et al, 2014;2015;Taubert et al, 2017). We discovered through transposon mutagenesis that the two-component NtrYX regulatory system (Fernandez et al, 2017) is a key player in the use of ectoines as nutrients by R. pomeroyi DSS-3.…”

Microbial metabolism of methanol and methylamine in the Gulf of Mexico: insight into marine carbon and nitrogen cycling

“…quaternary amines) (Anthony 1982;Yancey et al, 1982;King 1988;Lidbury et al, 2017). Methylamines contain both carbon and nitrogen and thus serve as carbon and energy sources as well as a potentially important nitrogen source to marine microorganisms (Taubert et al, 2017). Despite the low standing concentrations of methylamines in the ocean (nanomolar range; Naqvi et al, 2005), these compounds are likely characterized by a dynamic microbial cycle (Yang et al, 1994).…”