氧化还原介体催化强化Shewanella oneidensis MR-1还原亚硒酸盐的研究

摘要

Accelerating the selenite reduction rate is important in selenite bioreduction by microorganism process.This study investigates the impact of redox mediators (α-AQS,AQS,1,5-AQDS and AQDS)on bioreduction of selenite by Shewanella oneidensis MR-1 and optimizes the bioreduction conditions with Shewanella oneidensis MR-1 and AQDS.The selenium particles obtained from cultures are analyzed using Zeta potential analyzer.The results suggest that all four tested redox media-tors are able to accelerate the reduction of selenite by Shewanella oneidensis MR-1,and AQDS is the best.The optimum condi-tons are AQDS concentration of 0.2 mmol/L pH of 8.0 and temperature of 30 ℃.Selenite is completely removed after 48 h bioreduction by Shewanella oneidensis MR-1 with optimum conditons.Bigger size selenium nanoparticles (SeNPS)can be obtained with AQDS.AQDS may influence the composition and content of the organic layer covering around selenium nanopar-ticles (SeNPs).This study could provide a foundation for particle application in selenite biodegradation.%针对微生物还原亚硒酸盐过程普遍存在的时间较长的问题,考察了4种水溶性醌类介体(α-AQS,AQS,1,5-AQDS和AQDS)对奥奈达希瓦氏菌(Shewanella oneidensis MR-1)还原亚硒酸盐过程的加速作用,通过单因素试验优化了培养条件,对硒纳米颗粒的Zeta电位和粒径进行了表征.结果表明,4种醌类介体都加速了亚硒酸盐的还原,其中,AQDS的加速效果最显著;在pH值为8.0,温度为30℃,AQDS浓度为0.2 mmol/L条件下,48 h时亚硒酸盐的转化率达到100％;加入AQDS后会生成更大尺寸的硒纳米颗粒,并可能使硒纳米颗粒表面包裹的有机物质成分及含量发生改变.研究结果为Shewanella oneidensis MR-1修复亚硒酸盐污染的实际应用提供了理论依据.