Winogradsky Bioelectrochemical System as a Novel Strategy to Enrich Electrochemically Active Microorganisms from Arsenic-Rich Sediments

Abstract

Bioelectrochemical systems (BESs) have been extensively studied for treatment and remediation. However, BESs have the potential to be used for the enrichment of microorganisms that could replace their natural electron donor or acceptor for an electrode. In this study, Winogradsky BES columns with As-rich sediments extracted from an Andean watershed were used as a strategy to enrich lithotrophic electrochemically active microorganisms (EAMs) on electrodes (i.e., cathodes). After 15 months, Winogradsky BESs registered power densities up to 650 μWcm−2. Scanning electron microscopy and linear sweep voltammetry confirmed microbial growth and electrochemical activity on cathodes. Pyrosequencing evidenced differences in bacterial composition between sediments from the field and cathodic biofilms. Six EAMs from genera Herbaspirillum, Ancylobacter, Rhodococcus, Methylobacterium, Sphingomonas, and Pseudomonas were isolated from cathodes using a lithoautotrophic As oxidizers culture medium. These results suggest that the tested Winogradsky BES columns result in an enrichment of electrochemically active As-oxidizing microorganisms. A bioelectrochemical boost of centenarian enrichment approaches, such as the Winogradsky column, represents a promising strategy for prospecting new EAMs linked with the biogeochemical cycles of different metals and metalloids.

Searching for bacterial plastitrophs in modified Winogradsky columns

“…Here, we explore the bacteria of terrestrial plastispheres by employing a modified Winogradsky column. A Winogradsky column is a device used to enrich soil microorganisms of interest, including novel bacteria that can degrade certain compounds, including plastics (de Sousa et al, 2012;Cantillo-Gonzaĺez et al, 2022). These columns are named after Russian microbiologist Sergei Winogradsky, who developed the technique in the late 19th century (Winogradsky, 1890;Schlegel and Bowien, 1989).…”