Geothrix is a bacterial genus of iron reducers. In this corpus it appears with geobacter as a dominant member of rock-attached communities in Opalinus clay, as the cited literature describes 1,2. The assigned evidence gives no alias or external identifier (such as an NCBI taxid), so none is recorded here.
Mont Terri Opalinus clay
At the mont-terri Opalinus clay site, the Bagnoud (2016) porewater paradigm and the Mitzscherling (2023) rock-attached paradigm describe qualitatively different microbial communities at the same site. Sulfate reducers dominate the porewater, whereas Geobacter/Geothrix iron reducers dominate rock surfaces. This contrast is recorded as a discovery that rests on the two cited literature studies, not on a new measurement made in this corpus 1.
The cited Mitzscherling et al. (2023) rock-attached community profile reports sulfate-reducing bacteria (SRB) at <0.2% and iron-reducing bacteria (IRB) at 4.3–10.2%, dominated by Geobacter and Geothrix. The clay-confined subsurface project uses this profile as a literature comparator. It is not a corrected iron-marker result for that project’s cultured cohort 2.
Representation in the cultured cohort
In the clay-confined subsurface project, rock-attached Geobacter / Geothrix lineages are essentially absent from the analysed cohort, as are CPR / DPANN episymbionts (Bell 2022). The report therefore says that work augmented with MAGs (metagenome-assembled genomes) is needed to test whether the genuine clay-confined community matches the literature predictions. Until that work is done, the claim that Geothrix is prominent in clay-confined communities rests on the cited literature, because the lineage is essentially absent from this project’s analysed cohort 2.
Related pages
- geobacter: the iron-reducing genus reported alongside Geothrix on Opalinus rock surfaces 1
- mont-terri: the Opalinus clay site where the porewater and rock-attached communities were contrasted 1
- Self-Sufficiency, Anaerobic Toolkit, and Cultivation Bias in Clay-Confined Cultured Bacterial Genomes: the project that uses the rock-attached profile as a comparator and notes that these lineages are essentially absent from its analysed cohort 2
- discoveries: the cross-project digest that records the contrast between porewater and rock-attached communities 1