Investigating survival, morphology and bioremediation of uranium in native Shewanella RCRI7 from one-day and ten-day colonies

Abstract

Shewanella RCRI7 has the ability to reduce uranium under anaerobic conditions. Bacterial function of one- and ten-day cultured colonies in terms of uranium removal ability, morphological changes and viability in anaerobic solution containing uranium and nitrate has been investigated in this study. The results showed that one-day bacteria grew faster than ten-day bacteria at a concentration of 2 mM Uranium, while the uranium removal percentage of ten-day bacteria is higher than that of one-day bacteria, which are adsorbed by the bacterial masses through biosorption. Bioremediation of uranium in one-day cultured bacteria was confirmed by XRD analysis, spectrophotometry and morphological examination by light microscopy. 4-month and 9-month samples from one-day colony had 96% and 99% uranium removal, respectively, indicating the stability of soluble uranium removal over long periods of time. One-day and 4-month samples containing nitrate and uranium also confirmed the ability to remove uranium in the presence of nitrate at a concentration of 20 g /L, which shows the ability of this native bacterium to reduce the uranium in the presence of nitrate, introducing this as a suitable option for future studies.

Keywords

• shewanella rcri7
• uranium bioremediation
• spectrophotometry
• morphology
• xrd