| Title: | Microbial selenate detoxification linked to elemental sulfur oxidation: Independent and synergic pathways |
| Author(s): | Li L; Zhang B; Li L; Borthwick AGL; |
| Address: | "School of Water Resources and Environment, China University of Geosciences Beijing, Beijing 100083, China; Key Laboratory of Groundwater Circulation and Evolution (China University of Geosciences Beijing), Ministry of Education, Beijing 100083, China. School of Water Resources and Environment, China University of Geosciences Beijing, Beijing 100083, China; Key Laboratory of Groundwater Circulation and Evolution (China University of Geosciences Beijing), Ministry of Education, Beijing 100083, China. Electronic address: baogangzhang@cugb.edu.cn. St Edmund Hall, Queen's Lane, Oxford OX1 4AR, UK; School of Engineering, The University of Edinburgh, The King's Buildings, Edinburgh EH9 3JL, UK; School of Engineering, Computing and Mathematics, University of Plymouth, Drakes Circus, Plymouth PL4 8AA, UK" |
| DOI: | 10.1016/j.jhazmat.2021.126932 |
| ISSN/ISBN: | 1873-3336 (Electronic) 0304-3894 (Linking) |
| Abstract: | "Elevated selenium levels in the environment, with soluble selenate [Se(VI)] as the common chemical species, pose a severe threat to human health. Anaerobic Se(VI) bioreduction is a promising approach for selenium detoxification, and various organic/inorganic electron donors have proved effective in supporting this bioprocess. Nevertheless, autotrophic Se(VI) bioreduction driven by solid inorganic electron donors is still not fully understood. This work is the first to employ elemental sulfur [S(0)] as electron donor to support Se(VI) bioreduction. A batch trial with mixed culture demonstrated the feasibility of this bioprocess, with Se(VI) removal efficiency of 92.4 +/- 0.7% at an initial Se(VI) concentration of 10 mg/L within 36 h. Continuous column tests showed that increased initial concentration, flow rate, and introduction of NO(3)(-)-N depressed Se(VI) removal. Se(VI) was mainly bioreduced to solid elemental Se with trace selenite in the effluent, while S(0) was oxidized to SO(4)(2-). Enrichment of Thiobacillus, Desulfurivibrio, and Sulfuricurvum combined with upregulation of genes serA, tatC, and soxB indicated Se(VI) bioreduction was coupled to S(0) oxidation. Thiobacillus performed S(0) oxidation and Se(VI) reduction independently. Intermediate metabolites as volatile fatty acids, hydrogen and methane from S(0) oxidation were utilized by heterotrophic Se(VI) reducers for Se(VI) detoxification, indicative of microbial synergy" |
| Keywords: | Humans Oxidation-Reduction Selenic Acid Selenious Acid *Selenium *Selenium Compounds Sulfur Biodetoxification Elemental sulfur Microbial reduction Selenate; |
| Notes: | "MedlineLi, Liuliu Zhang, Baogang Li, Lei Borthwick, Alistair G L eng Research Support, Non-U.S. Gov't Netherlands 2021/08/23 J Hazard Mater. 2022 Jan 15; 422:126932. doi: 10.1016/j.jhazmat.2021.126932. Epub 2021 Aug 16" |
