PXD017709

PXD017709 is an original dataset announced via ProteomeXchange.

Title	Anaerobic sulfur oxidation underlies adaptation of a chemosynthetic symbiont to oxic-anoxic interfaces
Description	Chemosynthetic symbioses between bacteria and invertebrates occur worldwide in a wide range of marine habitats. Although they have been intensively investigated, molecular physiological studies of chemoautotrophic bacteria colonizing the surface of animals (ectosymbioses) are scarce. Stilbonematinae nematodes are the only known invertebrates capable of cultivating monocultures of thiotrophic Gammaproteobacteria on their surface. Crucially, as these nematodes migrate through the redox zone of marine sediments, the ectosymbionts directly experience drastic variations in oxygen concentration. Here, by applying an array of omics, Raman microspectroscopy and stable isotope labeling-based techniques, we investigated the effect of varying concentrations of dissolved oxygen on physiology and metabolism of Candidatus Thiosymbion oneisti, the longitudinally dividing ectosymbiont of Laxus oneistus. We show that, unexpectedly, sulfur oxidation genes were upregulated in anoxic relative to oxic conditions, and that carbon fixation genes and incorporation of 13C-labeled bicarbonate were not. Instead, several genes involved in carbon fixation in addition to genes responsible for assimilating organic carbon compounds and polyhydroxyalkanoate (PHA) biosynthesis, as well as nitrogen fixation and urea utilization genes were upregulated in oxic versus anoxic conditions. Furthermore, in the presence of oxygen, stress-related genes were upregulated together with vitamin and cofactor biosynthesis genes likely necessary to withstand its deleterious effects. Based on this first global physiological study of an uncultured, chemosynthetic ectosymbiont, we propose that, in anoxic pore water, it proliferates by utilizing nitrate to oxidize reduced sulfur compounds, whereas, when exposed to oxygen, it exploits aerobic respiration to facilitate energetically costly assimilation of carbon and nitrogen to survive oxidative stress. Both anaerobic sulfur oxidation and its decoupling from carbon fixation represent unprecedented adaptations among chemosynthetic symbionts. We postulate that Ca. T. oneisti originated from an obligate anaerobic, denitrifying sulfur-oxidizer, which, while transitioning from the free-living to the symbiotic lifestyle, evolved mechanisms to survive the oxidative stress inherent to a life attached to an animal.
HostingRepository	PRIDE
AnnounceDate	2021-11-10
AnnouncementXML	Submission_2021-11-10_07:46:42.889.xml
DigitalObjectIdentifier	https://dx.doi.org/10.6019/PXD017709
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Supported dataset by repository
PrimarySubmitter	Stephanie Markert
SpeciesList	scientific name: Candidatus Thiosymbion oneisti; NCBI TaxID: 589554; scientific name: Laxus oneistus; NCBI TaxID: 74811;
ModificationList	Oxidation
Instrument	LTQ Orbitrap Velos

Revision	Datetime	Status	ChangeLog Entry
0	2020-02-24 22:48:23	ID requested
⏵ 1	2021-11-10 07:46:43	announced

Dataset with its publication pending

submitter keyword: nematodes, symbionts, thiotrophy, oxic, anoxic

Stephanie Markert
contact affiliation	Universität Greifswald Institut für Pharmazie, AG Pharmazeutische Biotechnologie Greifswald, Germany
contact email	stephanie.markert@uni-greifswald.de
lab head
Stephanie Markert
contact affiliation	University of Greifswald
contact email	stephanie.markert@uni-greifswald.de
dataset submitter

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PRIDE project URI

• PRIDE
  1. PXD017709
     1. Label: PRIDE project
     2. Name: Anaerobic sulfur oxidation underlies adaptation of a chemosynthetic symbiont to oxic-anoxic interfaces