Contribution of Extracellular Polymeric Substances from Shewanella sp. HRCR-1 Biofilms to U(VI) Immobilization

Citations Over TimeTop 10% of 2011 papers

Abstract

The goal of this study was to quantify the contribution of extracellular polymeric substances (EPS) to U(VI) immobilization by Shewanella sp. HRCR-1. Through comparison of U(VI) immobilization using cells with bound EPS (bEPS) and cells with minimal EPS, we show that (i) bEPS from Shewanella sp. HRCR-1 biofilms contribute significantly to U(VI) immobilization, especially at low initial U(VI) concentrations, through both sorption and reduction; (ii) bEPS can be considered a functional extension of the cells for U(VI) immobilization and they likely play more important roles at lower initial U(VI) concentrations; and (iii) the U(VI) reduction efficiency is dependent upon the initial U(VI) concentration and decreases at lower concentrations. To quantify the relative contributions of sorption and reduction to U(VI) immobilization by EPS fractions, we isolated loosely associated EPS (laEPS) and bEPS from Shewanella sp. HRCR-1 biofilms grown in a hollow fiber membrane biofilm reactor and tested their reactivity with U(VI). We found that, when reduced, the isolated cell-free EPS fractions could reduce U(VI). Polysaccharides in the EPS likely contributed to U(VI) sorption and dominated the reactivity of laEPS, while redox active components (e.g., outer membrane c-type cytochromes), especially in bEPS, possibly facilitated U(VI) reduction.

Related Papers

• → Investigating the interaction between Shewanella oneidensis and phenazine 1-carboxylic acid in the microbial electrochemical processes(2022)14 cited
• → Biogenic Formation of As-S Nanotubes by Diverse Shewanella Strains(2009)55 cited
• → Comparisons of Shewanella strains based on genome annotations, modeling, and experiments(2014)39 cited
• → Patterned Hydrophobic Domains in the Exopolymer Matrix of Shewanella oneidensis MR-1 Biofilms(2012)22 cited
• Metabolic networks of electricigens Shewanella for anaerobic respiration(2015)