News

Global niche of marine anaerobic metabolisms expanded by particle microenvironments

Abstract.

"In ocean waters, anaerobic microbial respiration should be confined to the anoxic waters found in coastal regions and tropical oxygen minimum zones, where it is energetically favourable. However, recent molecular and geochemical evidence has pointed to a much broader distribution of denitrifying and sulfate-reducing microbes. [...]"

Source: Nature Geoscience
Authors: Daniele Bianchi et al.
DOI: 10.1038/s41561-018-0081-0

Read the full article here.


Insights into the metabolic functioning of a multipartner ciliate symbiosis from oxygen-depleted sediments

Abstract.

"Symbioses between anaerobic or microaerophilic protists and prokaryotes are common in anoxic and oxygen-depleted habitats ranging from marine sediments to gastrointestinal tracts. Nevertheless, little is known about the mechanisms of metabolic interaction between partners. In these putatively syntrophic associations, consumption of fermentative end products (e.g., hydrogen) by the prokaryotic symbionts is thought to facilitate protistan anaerobic metabolism.  [...]"

Source: Molecular Ecology
Authors: R. A. Beinart et al.
DOI: 10.1111/mec.14465

Read the full article here.


Microbial oceanography of anoxic oxygen minimum zones

Abstract.

"Vast expanses of oxygen-deficient and nitrite-rich water define the major oxygen minimum zones (OMZs) of the global ocean. They support diverse microbial communities that influence the nitrogen economy of the oceans, contributing to major losses of fixed nitrogen as dinitrogen (N2) and nitrous oxide (N2O) gases. Anaerobic microbial processes, including the two pathways of N2 production, denitrification and anaerobic ammonium oxidation, are oxygen-sensitive, with some occurring only under strictly anoxic conditions. The detection limit of the usual method (Winkler titrations) for measuring dissolved oxygen in seawater, however, is much too high to distinguish low oxygen conditions from true anoxia.  [...]"

Source: Proceedings of the National Academy of Science of the United States of America (PNAS)
Authors: Osvaldo Ulloa et al.
DOI: 10.1073/pnas.1205009109

Full article