Tellurite exposure can cause the formation of intracellular radical oxygen species (ROS) , leading to cellular damage. Catalases, the key enzymatic defence against ROS, play a role in mitigating the detrimental effects of the toxin. In Staphylococcus epidermidis, this family of enzymes is also capable of using TeO32− as a substrate, reducing it to Te , therefore minimizing the negative impact on cells. In E. coli, reduction of tellurite can occur through the actions of nitrate reductases, however, this is a non-specific reaction . Other enzymes, such as the thiol:disulfide oxidoreductase of Rhodobacter capsulatus , GutS from E. coli , among others  have been implicated in tellurite resistance and/or reduction. Although they are associated with low to moderate levels of resistance, it is not their primary specific function. In the case of R. capsulatus, multiple approaches to dealing with tellurite have been observed. One involves maintaining redox poise during photosynthetic growth through the reduction of tellurite , while another is based on reduced uptake of the tellurite oxyanion. With the latter, acetate permease is responsible for TeO32− influx  and competition between it and acetate for entry into the cell results in higher resistance. Even at low concentrations (60 ng/mL), acetate impacts tellurite entry , limiting toxicity. A related approach has been identified in E. coli. Mutation to a phosphate transport system provided enhanced resistance , which allowed tellurite ingress. Lastly, certain microorganisms can somewhat neutralize Te oxyanions by production of volatile organic telluride compounds, such as dimethyltelluride , however, such approach to detoxification delivers negligible removal.