Impact of pH and salinity fluctuations on oxidation of Fe(II) by nitrate-reducing microorganisms enriched from the reduced tidal sediment of an extreme acidic river (Rio Tinto, Spain).

ABSTRACT: Nitrate reduction coupled to Fe(II) oxidation (NRFeOx) contributes to Fe cycling in the estuarian sediments of the Río Tinto river (Huelva, Spain). However, it is not yet known (i) whether and which NRFeOx microorganisms can be enriched from the reduced sediment layer and (ii) how in situ pH and salinity fluctuations affect NRFeOx. Therefore, we (i) used two different approaches, such as microcosm experiments (sediment amended with either NO3-/Fe2+aq or acetate/NO3-/Fe2+aq) and enrichment cultures (medium amended with acetate/NO3-/Fe2+aq) to enrich NRFeOx microorganisms to (ii) test their salinity and pH tolerance under simulated high tide and low tide conditions. We found that different microorganisms such as Thiobacillus (up to 9.7 ± 5.8% DNA-based 16S rRNA gene abundance) and Denitromon

SUBMITTER: Bottaro M 

PROVIDER: S-EPMC12475565 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature