(1. 九江學(xué)院 化學(xué)與環(huán)境工程學(xué)院，九江 332005；2. 北京科技大學(xué) 土木與環(huán)境工程學(xué)院，北京 100083)
摘 要: 以膠質(zhì)芽孢桿菌CGMCC11和環(huán)狀芽孢桿菌CGMCC12為出發(fā)菌株，采用亞硝酸鈉對(duì)其進(jìn)行誘變育種與浸礦研究。結(jié)果表明：菌株CGMCC11和CGMCC12的最適生長(zhǎng)溫度分別為28和30 ℃，最適pH值分別為7.2和8.3。采用40和60 mg/L亞硝酸鈉分別處理出發(fā)菌株CGMCC11和CGMCC12，致死率分別為87%和85%，正突變率分別為18% 和 20%；篩選獲得兩株突變菌CGMCC11KP和CGMCC12KP，其達(dá)到生長(zhǎng)穩(wěn)定期的時(shí)間分別比對(duì)應(yīng)的出發(fā)菌株達(dá)到生長(zhǎng)穩(wěn)定期的時(shí)間縮短了48和24 h，且具有更大的菌體密度、產(chǎn)酸和產(chǎn)大分子胞外聚合物的能力。浸礦15 d，與對(duì)應(yīng)的出發(fā)菌株相比，突變菌株CGMCC11KP和CGMCC12KP溶出的SiO2量分別提高了30.47%和29.57%，且達(dá)到浸出終點(diǎn)的時(shí)間分別提前了5和3 d；混合誘變菌株浸出液中SiO2 的量分別比對(duì)應(yīng)的誘變菌株浸出液中SiO2的量提高了20.0% 和37.5%，且達(dá)到浸出終點(diǎn)的時(shí)間比出發(fā)菌株達(dá)到浸出終點(diǎn)的時(shí)間提前了6 d。SEM和XRD結(jié)果表明：混合誘變菌株對(duì)鋁土礦的溶蝕分解最為明顯，混合浸出15 d后，誘變前后膠質(zhì)芽孢桿菌CGMCC11 和環(huán)狀芽孢桿菌CGMCC12的菌落個(gè)數(shù)比由1:1變?yōu)?0:1。
關(guān)鍵字: 膠質(zhì)芽孢桿菌；環(huán)狀芽孢桿菌；亞硝酸鈉；誘變；細(xì)菌浸出； 脫硅；鋁土礦
（1. School of Chemistry and Environmental Engineering, Jiujiang University, Jiujiang 332005, China;2. School of Civil and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China）
Abstract:The original strains, Bacillus mucilaginosus CGMCC11 and Bacillus circulans CGMCC12, were treated by sodium nitrite to induce mutagenesis and investigate bioleaching of bauxite. The results show that the optimum temperature and pH value are 28 ℃ and 7.2 for B·M CGMCC11, and 30 ℃ and 8.3 for B·C CGMCC12. The lethal rates of B·M CGMCC11 and B·C CGMCC12 are 87% and 85%, and the positive mutant rates are 18% and 20% after being treated by 40 and 60 mg/L sodium nitrite culturing, respectively. The two mutants, B·M CGMCC11KP and B·C CGMCC12KP, screened from positive mutant strains reach stationary stages by 48 and 24 h ahead of the corresponding original strains, and have higher bacterial concentrations and higher ability of producing organic acids and macromolecule extracellular polymers than the original strains. After leaching for 15 d, the SiO2 concentrations in supernatants of the mutant stains of B·M CGMCC11KP and B·C CGMCC12KP are improved by 30.47% and 29.57%, and the leaching time of 5 and 3 d shorter, respectively, than those of the two corresponding original strains. After bioleaching with the mixture of B·M CGMCC11KP and B·C CGMCC12KP, the SiO2 concentration of the supernatant is 20.0% and 37.5% higher than those of the corresponding mutants, and the mixture can shorten the leaching time by 6 d in comparison with the original strains. The SEM and XRD analyses of bauxite surfaces before and after leaching show that the mixture of B·M CGMCC11KP and B·C CGMCC12KP has the greatest corrosion and decomposition ability on bauxite. After bioleaching for 15 d, the proportion of cell density in the supernatants of B·M CGMCC11 and B·C CGMCC12 is changed from 1:1 to approximately 10:1.
Key words: Bacillus mucilaginosus; Bacillus circulans; sodium nitrite; mutagenesis; bioleaching; desilicon; bauxite
