Product inhibition of β-glucosidases directly measured by calorimetry

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 52 KB
• Volume: 107
• Category: Article
• ISSN: 0006-3592
• DOI: 10.1002/bit.22950

✦ Synopsis

Uranium mining and processing has led to widespread uranium and nitrate contamination in groundwater. Bioremediation of uranium can be achieved by bacteria that reduce the soluble hexavalent form (U VI ) to the insoluble tetravalent form (U IV ), thereby preventing its migration with groundwater. However, nitrate causes the oxidation of U IV , which results in uranium remobilization. In this issue of Biotechnology and Bioengineering, sequential biotreatment of nitrate and U VI co-contamination is proposed by Luna-Velasco and co-workers. This innovative treatment system consists of a bioreactor packed with elemental sulfur used for denitrification, followed by a bioreactor packed with a mixture of zero-valent iron (ZVI) and sand for uranium removal. The authors show that nitrate and uranium in synthetic groundwater were successfully removed. Furthermore, microbial activity in the ZVI/sand bioreactor was found to greatly enhance uranium reduction. Sulfide produced in the denitrifying bioreactor precipitated in the ZVI bioreactor as iron sulfide, which is a mineral that can help protect U IV from re-oxidation.