Electron transfer routes in nitrate-pentavalent vanadium co-contaminated system of oligotrophic microbiology niche

• Published in: The Science of the total environment 2023-04, Vol.870, p.161834-161834, Article 161834
• Main Authors: Wang, Haishuang, Chen, Nan, Feng, Chuanping, Deng, Yang, Yang, Mengnan, Guo, Huaming
• Format: Article
• Language: English
• Subjects: Electron transfer; Electron Transport; Electrons; Nitrate; Nitrates; Oligotrophic microbiology niche; Oxidation-Reduction; Pentavalent vanadium; Substance metabolism; Vanadium - metabolism
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2023.161834

Microbial techniques have been extensively used for the remediation of nitrate and V(V) co-contaminations, but the mechanisms of electron and substances transport and metabolism of co-contaminations under oligotrophic niche have been largely overlooked. This study quantified the electron transfer and consumption, substance transfer, and metabolic pathways in the nitrate and V(V) co-contamination system under oligotrophic condition to explore the underlying mechanisms by characterizing the products and elucidating conventional cognitive pathways. This study compared the composition of the precipitates under the conditions of sufficient and insufficient carbon sources using energy-dispersive X-ray spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy, and discovered the re-oxidation process of the already reduced V(IV). Electronic evidence for the re-oxidation process of V(IV) was also provided by electron transfer and quantitative analysis. Besides, this study found that the electron contribution ratio of NO3−-N → NO2−-N and V(V) → V(IV) reduction was 40.2:1. In addition, based on the functional prediction of PICRUSt 2, it was found that the utilization of intracellular reserve carbon source and enzymes in the transport chain were enhanced in oligotrophic microbiology niche. These results provide new insights into the stability of co-contamination reduction in oligotrophic microbiology niche and demonstrate a new mobilization pathway for V(V) in oligotrophic systems. [Display omitted] •The process of V(V) → V(IV) → V(V) existed at oligotrophic condition.•Oxidation of V(IV) to V(V) provided electrons for denitrification.•Carbon source deficiency enhanced the utilization of intracellular reserve carbon source.•The ratio of electron contribution to NO3−-N → NO2−-N and V(V) → V(IV) reduction was 40.2:1.