The Chemistry of Microbiomes Proceedings of a Seminar Series (2017) / Chapter Skim
Currently Skimming:
7 Organic Nutrient Chemistry and the Marine Microbiome - Daniel J. Repeta and Rene M. Boiteau
7 Organic Nutrient Chemistry and the Marine Microbiome - Daniel J. Repeta and Rene M. Boiteau
Pages 43-52
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 43... ...
However, some escapes immediate remineralization and accumulates in the water column, where it slowly degrades over several years. DOC concentrations are 40-80 µM throughout the water column, while dissolved organic nitrogen (DON)
|
From page 44... ...
Here, we highlight two aspects of organic phosphorus chemistry and trace metal cycling in the marine microbiome. In each study, advances in chemical analyses, microbial culture, and microbial genomics played key roles in understanding how microbial communities interact to facilitate nutrient cycling in the open ocean.
|
From page 45... ...
Photoautotrophs and heterotrophs synthesize organic phosphorus–containing compounds including nucleic acids, phosphorylated proteins, phospholipids, and for microbes with the Pep mutase metabolic pathway, a suite of phosphonopolysaccharides. Organophosphorus compounds are released to the water column by grazing and from cell lysis following viral infection, but are quickly metabolized to phosphate by heterotrophic bacteria.
|
From page 46... ...
Nearly 50 years ago, geochemists first reported that the upper ocean is supersaturated with respect to the atmosphere in methane, a greenhouse gas that is produced by Archea under strictly anaerobic conditions. The presence of high concentrations of methane in well-oxygenated surface waters therefore posed a challenge to microbial biogeochemistry, which was posed as a "marine methane paradox." Microbial degradation of methylphosphonate provides one solution to the methane paradox, in which methane is released as a byproduct of microbial cycling of HMWDOM phosphonates.
|
From page 47... ...
Marine organic geochemists have sought to characterize iron-binding organic compounds in seawater and understand how these compounds mediate microbial uptake. Since dissolved organic carbon concentrations typically exceed dissolved iron concentrations by 4-6 orders of magnitude, characterization of organically chelated iron is therefore a formidable task that relies on identifying trace components within a complex and abundant organic matrix.
|
From page 48... ...
In the eastern tropical South Pacific Ocean, the composition of microbially produced siderophores changes across major nutrient regimes (Boiteau et al., 2016)
|
From page 49... ...
The high concentrations of amphibactins measured in the low-iron region of the eastern tropical South Pacific Ocean made amphibactin synthesis genes attractive targets for metagenome-based surveys of siderophore production. Amphibactins are synthesized by a pair of nonribosomal protein synthetase (NRPS)
|
From page 50... ...
A knowledge of chemical speciation greatly facilitates the interrogation of ocean metagenomic data catalogs, which can help to identify the specific microbial taxa that produce and consume organic nitrogen, phosphorus, and trace metals. Finally, using advanced microbial culture approaches, including dilution-to-extinction, marine microbiologists can quickly bring microbes with targeted metabolic capabilities into laboratory culture for detailed studies of metabolic pathways.
|
From page 51... ...
2009. The alkaline phosphatase Pho X is more widely distributed in marine bacteria than classical Pho A
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.