The Effect of Carbon Source Loading on Selenite Reduction by Enterococcus Spp

Abstract

This study investigated the bioremediation capabilities of Enterococcus spp. for mitigating selenite (SeO₃^2-) contamination, focusing on the impact of varied carbon source loadings. The investigation not only explored the bioremediation potential but also endeavoured to elucidate the underlying mechanisms governing selenite bioremediation. Carbon source selection emerged as a critical determinant, significantly influencing SeO₃^2- reduction, elemental selenium (Se⁰) formation, and protein synthesis. Aerobic batch experiments were conducted to reduce an initial SeO₃^2- concentration of 1 mM. In each case, the carbon source was either glucose, cooking oil or crude oil. Glucose and cooking oil were identified as the most efficient carbon sources, facilitating rapid SeO₃^2- reduction. Of the initial SeO₃^2- concentration (1 mM) ,59 % and 56 % reduction was observed in the presence of glucose and crude oil respectively, after 50 h. In contrast, crude oil, only resulted in a 39 % reduction. Findings from this study not only underscored the efficiency of Enterococcus spp. in selenite reduction but also highlighted the influence of carbon sources on the overall bioremediation process. The identification of glucose and cooking oil as optimal carbon sources opens avenues for further research into tailoring bioremediation strategies based on specific environmental conditions.