Cable bacteria regulate sedimentary phosphorus release in freshwater sediments.

Autor: Xu X; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Science, Beijing 100012, China., Weng N; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Science, Beijing 100012, China. Electronic address: weng.nanyang@craes.org.cn., Zhang H; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Science, Beijing 100012, China., van de Velde SJ; Department of Biology, University of Antwerp, Wilrijk, Belgium; Operationale Directorate Natural Environment, Royal Belgian Institute of Natural Sciences, Brussels, Belgium., Hermans M; Baltic Sea Centre, Stockholm University, Stockholm 106 91, Sweden; Environmental Geochemistry Group, Faculty of Science, University of Helsinki, Helsinki 00560, Finland., Wu F; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Science, Beijing 100012, China., Huo S; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Science, Beijing 100012, China. Electronic address: huoshouliang@126.com.
Jazyk: angličtina
Zdroj: Water research [Water Res] 2023 Aug 15; Vol. 242, pp. 120218. Date of Electronic Publication: 2023 Jun 12.
DOI: 10.1016/j.watres.2023.120218
Abstrakt: Previous studies have demonstrated that e-SO x can regulate the sedimentary release of phosphorus (P) in brackish and marine sediments. When e-SO x is active, an iron (Fe) and manganese (Mn) oxide rich layer is formed near the sediment surface, which prevents P release. When e-SO x becomes inactive, the metal oxide layer is reduced via sulfide-mediated dissolution, and P is subsequently released to the water column. Cable bacteria have been shown to also occur in freshwater sediments. In these sediments, sulfide production is limited, and the metal oxide layer would thus dissolve less efficiently, leaving the P trapped at the sediment surface. This lack of an efficient dissolution mechanism implies that e-SO x could play an important role in the regulation of P availability in eutrophied freshwater streams. To test this hypothesis, we incubated sediments from a eutrophic freshwater river to investigate the impact of cable bacteria on sedimentary cycling of Fe, Mn and P. High-resolution depth profiling of pH, O 2 and ΣH 2 S complemented with FISH analysis and high-throughput gene sequencing showed that the development of e-SO x activity was closely linked to the enrichment of cable bacteria in incubated sediments. Cable bacteria activity caused a strong acidification in the suboxic zone, leading to the dissolution of Fe and Mn minerals and consequently a strong release of dissolved Fe 2+ and Mn 2+ to the porewater. Oxidation of these mobilized ions at the sediment surface led to the formation of a metal oxide layer that trapped dissolved P, as shown by the enrichment of P-bearing metal oxides in the top layer of the sediment and low phosphate in the pore and overlying water. After e-SO x activity declined, the metal oxide layer did not dissolve and P remained trapped at the surface. Overall, our results suggested cable bacteria can play an important role to counteract eutrophication in freshwater systems.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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