亚硒酸盐还原菌除硒效果与吸附机理分析

为了研究除硒微生物特性,作者从江西某富硒泉水中分离到4株亚硒酸盐还原菌,并进行除硒效果与机理分析。4株亚硒酸盐还原菌表现出很强的亚硒酸耐受能力,在7 mmol/L(553 mg/L)的亚硒酸浓度下生长良好。通过16S r DNA基因序列分析,4株细菌均为芽孢杆菌属(Bacillus)。在18 h内,它们对33 mg/L的亚硒酸去除率均高于99. 7%。B菌在75 h内对高浓度亚硒酸钠(197. 5 mg/L)去除率在达到91. 2%。扫描电镜(SEM)结果表明,经过高浓度含硒废水处理的细菌表面形态完整,能谱分析(EDS)证明硒元素在细胞表面存在。红外光谱(FTIR)分析表明,除硒后羟基、酰胺基基团等峰位发生了明显移位,表明它们在细菌吸附除硒中起重要作用。

Selenite Removal Efficiency and Mechanism Analysis of Selenite Reduction Bacteria

In order to learn the characteristics of selenite removal bacteria,4 strains of selenite reducing bacteria were isolated from a Selenium-rich spring in Jiangxi Province.The selenite removal efficiency and mechanism were also analysed.The 4 strains had strong selenite tolerance capacities,which could live well under selenite concentration of 7 m mol/L (553 mg/L).The isolated bacteria are all related to Bacillus genus based on 16S rDNA gene sequencing analysis.After exposure to 33 mg/L selenite,the maximum removal efficiencies were above 99.7% for the 4 bacteria within 18 h.A removal efficiency of 91.2% was achieved by B strain under high concentration of selenite (197.5 mg/L) exposure within 75 hours.Scanning electron microscope (SEM) results show that the surface of bacteria remained complete shape after high selenite concentrations exposure.Energy dispersive spectrum (EDS) analysis confirmed that selenium (Se) was existed on the surface of bacteria.Fourier transform infrared spectrometer (FTIR) results revealed the peaks position of amide and hydroxyl shifted evidently after selenite removal,which indicated they played main roles in selenite adsorption removal.