Academic Journal
Promotion of Humic Acid Transformation by Abiotic and Biotic Fe Redox Cycling in Nontronite
| العنوان: | Promotion of Humic Acid Transformation by Abiotic and Biotic Fe Redox Cycling in Nontronite |
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| المؤلفون: | Dafu Hu, Qiang Zeng, Jin Zhu, Chen He, Quan Shi, Hailiang Dong |
| سنة النشر: | 1753 |
| مصطلحات موضوعية: | Biochemistry, Microbiology, Physiology, Evolutionary Biology, Ecology, Space Science, Environmental Sciences not elsewhere classified, Biological Sciences not elsewhere classified, Chemical Sciences not elsewhere classified, premium electron donor, geobacter sulfurreducens <, electron shuttling capacity, fe ( iii, subsequent biological reduction, subsequent abiotic reoxidation, redox dynamic environments, transformed ha served, transformed ha increased, fe redox cycling, humic acid transformation, humic acid, transformed ha, fluctuating environments, effectively transformed, redox activity, model fe, unaltered ha, transforming ha, bleached ha, · oh |
| الوصف: | The redox activity of Fe-bearing minerals is coupled with the transformation of organic matter (OM) in redox dynamic environments, but the underlying mechanism remains unclear. In this work, a Fe redox cycling experiment of nontronite (NAu-2), an Fe-rich smectite, was performed via combined abiotic and biotic methods, and the accompanying transformation of humic acid (HA) as a representative OM was investigated. Chemical reduction and subsequent abiotic reoxidation of NAu-2 produced abundant hydroxyl radicals (thereafter termed as ·OH) that effectively transformed the chemical and molecular composition of HA. More importantly, transformed HA served as a more premium electron donor/carbon source to couple with subsequent biological reduction of Fe(III) in reoxidized NAu-2 by Geobacter sulfurreducens , a model Fe-reducing bacterium. Destruction of aromatic structures and formation of carboxylates were mechanisms responsible for transforming HA into an energetically more bioavailable substrate. Relative to unaltered HA, transformed HA increased the extent of the bioreduction by 105%, and Fe(III) reduction was coupled with oxidation and even mineralization of transformed HA, resulting in bleached HA and formation of microbial products and cell debris. ·OH transformation slightly decreased the electron shuttling capacity of HA in bioreduction. Our results provide a mechanistic explanation for rapid OM mineralization driven by Fe redox cycling in redox-fluctuating environments. |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | unknown |
| Relation: | https://figshare.com/articles/journal_contribution/Promotion_of_Humic_Acid_Transformation_by_Abiotic_and_Biotic_Fe_Redox_Cycling_in_Nontronite/24578679 |
| DOI: | 10.1021/acs.est.3c05646.s001 |
| الاتاحة: | https://doi.org/10.1021/acs.est.3c05646.s001 https://figshare.com/articles/journal_contribution/Promotion_of_Humic_Acid_Transformation_by_Abiotic_and_Biotic_Fe_Redox_Cycling_in_Nontronite/24578679 |
| Rights: | CC BY-NC 4.0 |
| رقم الانضمام: | edsbas.69C3B269 |
| قاعدة البيانات: | BASE |
| DOI: | 10.1021/acs.est.3c05646.s001 |
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