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Dissimilatory iron reduction contributes to anaerobic mineralization of sediment in a shallow transboundary lake

Authors :
Yuxiang Yuan
Cong Ding
Haitao Wu
Xue Tian
Min Luo
Weiyi Chang
Lei Qin
Liang Yang
Yuanchun Zou
Kaikai Dong
Xiaoyan Zhu
Ming Jiang
Marinus L. Otte
Source :
Fundamental Research, Vol 3, Iss 6, Pp 844-851 (2023)
Publication Year :
2023
Publisher :
KeAi Communications Co. Ltd., 2023.

Abstract

Dissimilatory iron reduction (DIR) coupled with carbon cycling is increasingly being recognized as an influential process in freshwater wetland soils and sediments. The role of DIR in organic matter (OM) mineralization, however, is still largely unknown in lake sediment environments. In this study, we clarified rates and pathways of OM mineralization in two shallow lakes with seasonal hydrological connectivity and different eutrophic situations. We found that in comparison with the domination of DIR (55%) for OM mineralization in Lake Xiaoxingkai, the contribution of methanogenesis was much higher (68%) in its connected lake (Lake Xingkai). The differences in rates and pathways of sediment OM mineralization between the two lakes were attributed to higher concentrations of carbonate associated iron oxides (Fecarb) in Lake Xiaoxingkai compared to Lake Xingkai (P = 0.002), due to better deposition mixing, more contributions of terrigenous detrital materials, and higher OM content in Lake Xiaoxingkai. Results of structural equation modeling showed that Fecarb and total iron content (TFe) regulated 25% of DIR in Lake Xiaoxingkai and 76% in Lake Xingkai, accompanied by a negative effect of TFe on methanogenesis in Lake Xingkai. The relative abundance and diversity of Fe-reducing bacteria were significantly different between the two lakes, and showed a weak effect on sediment OM mineralization. Our findings emphasize the role of iron minerals and geochemical characterizations in regulating rates and pathways of OM mineralization, and deepen the understanding of carbon cycling in lake sediments.

Details

Language :
English
ISSN :
26673258
Volume :
3
Issue :
6
Database :
Directory of Open Access Journals
Journal :
Fundamental Research
Publication Type :
Academic Journal
Accession number :
edsdoj.2e1383ae44cf43edbaa0fb1497bb7670
Document Type :
article
Full Text :
https://doi.org/10.1016/j.fmre.2022.12.002