An electrochemical sensing approach for scouting microbial chemolithotrophic metabolisms

Abstract

The present study was aimed to test an electrochemical sensing approach for the detection of an active chemolithotrophic metabolism (and therefore the presence of chemolithotrophic microorganisms) by using the corrosion of pyrite by Acidithiobacillus ferrooxidans as a model. Different electrochemical techniques were combined with adhesion studies and scanning electron microscopy (SEM). The experiments were performed in presence or absence of A. ferrooxidans and without or with ferrous iron in the culture medium (0 and 0.5 g L, respectively). Electrochemical parameters were in agreement with voltammetric studies and SEM showing that it is possible to distinguish between an abiotically-induced corrosion process (AIC) and a microbiologically-induced corrosion process (MIC). The results show that our approach not only allows the detection of chemolithotrophic activity of A. ferrooxidans but also can characterize the corrosion process. This may have different kind of applications, from those related to biomining to life searching missions in other planetary bodies.

Biooxidation of Iron by Acidithiobacillus ferrooxidans in the Presence of D-Galactose: Understanding Its Influence on the Production of EPS and Cell Tolerance to High Concentrations of Iron

“…The presence of EPS in biohydrometallurgical processes would favor bacterial attachment to the mineral and its subsequent role in the formation of biofilm on minerals, increasing the chemical attack on the mineral, and therefore the efficiency of the process. Hence, the production of EPS in planktonic cells can generate cells with high attachment capacity (Saavedra et al, 2018) in addition to conferring protection against harsh conditions (Wenbin et al, 2011). There are studies where different processes have been carried out for the generation of EPS in planktonic cells; for example, Biosigma, a biomining development company, presented a patent where a strategy to increase the production of EPS is described; thus, by silencing genes through redirecting the source of carbon to the formation of EPS and not to the formation of biomass (Mass et al, 2015).…”