Chromate[Cr(VI)]contamination in groundwater is a global environmental challenge.Traditional elemental sulfur-based biotechnologies for Cr(VI)removal depend heavily on the synthesis of dissolved organic carbon to fuel...Chromate[Cr(VI)]contamination in groundwater is a global environmental challenge.Traditional elemental sulfur-based biotechnologies for Cr(VI)removal depend heavily on the synthesis of dissolved organic carbon to fuel heterotrophic Cr(VI)reduction,a bottleneck in the remediation process.Here we show an alternative approach by leveraging sulfur-disproportionating bacteria(SDB)inherent to groundwater ecosystems,offering a novel and efficient Cr(VI)removal strategy.We implemented SDB within a sulfur-packed bed reactor for treating Cr(VI)-contaminated groundwater,achieving a notable removal rate of 6.19 mg L^(-1) h^(-1) under oligotrophic conditions.We identified the chemical reduction of Cr(VI)via sulfide,produced through sulfur disproportionation,as a key mechanism,alongside microbial Cr(VI)reduction within the sulfur-based biosystem.Genome-centric metagenomic analysis revealed a symbiotic relationship among SDB,sulfur-oxidizing,and chromate-reducing bacteria within the reactor,suggesting that Cr(VI)detoxification by these microbial communities enhances the sulfurdisproportionation process.This research highlights the significance of sulfur disproportionation in the cryptic sulfur cycle in Cr(VI)-contaminated groundwater and proposes its practical application in groundwater remediation efforts.展开更多
基金the support from the National Natural Science Foundation of China(No.51978289,U23A2049)the Science and Technology Planning Project of Guangdong Province(2021A0505020010).
文摘Chromate[Cr(VI)]contamination in groundwater is a global environmental challenge.Traditional elemental sulfur-based biotechnologies for Cr(VI)removal depend heavily on the synthesis of dissolved organic carbon to fuel heterotrophic Cr(VI)reduction,a bottleneck in the remediation process.Here we show an alternative approach by leveraging sulfur-disproportionating bacteria(SDB)inherent to groundwater ecosystems,offering a novel and efficient Cr(VI)removal strategy.We implemented SDB within a sulfur-packed bed reactor for treating Cr(VI)-contaminated groundwater,achieving a notable removal rate of 6.19 mg L^(-1) h^(-1) under oligotrophic conditions.We identified the chemical reduction of Cr(VI)via sulfide,produced through sulfur disproportionation,as a key mechanism,alongside microbial Cr(VI)reduction within the sulfur-based biosystem.Genome-centric metagenomic analysis revealed a symbiotic relationship among SDB,sulfur-oxidizing,and chromate-reducing bacteria within the reactor,suggesting that Cr(VI)detoxification by these microbial communities enhances the sulfurdisproportionation process.This research highlights the significance of sulfur disproportionation in the cryptic sulfur cycle in Cr(VI)-contaminated groundwater and proposes its practical application in groundwater remediation efforts.
