高硒碳质泥岩中的3株高还原耐受亚硒酸盐菌  

Three high-reducing selenite-tolerance bacteria from high-Se carbonaceous mudstone

作　　者：袁永强[1,2] 朱建明[1] 刘丛强[1] 雷磊[1,2] 

机构地区：[1]中国科学院地球化学研究所环境地球化学国家重点实验室,贵州贵阳550002 [2]中国科学院大学,北京100049

出　　处：《地学前缘》2014年第2期331-341,共11页Earth Science Frontiers

基　　金：国家自然科学基金创新群体项目(41021062);国家自然科学基金项目(41173030);中国科学院知识创新工程重要方向项目(KZCX2-EW-102)

摘　　要：文中研究了高硒碳质泥岩中的3株细菌Bacillus licheni formis SeRB-1、Bacillus sp．SeRB-2和Arthrobacter sp．SeRB-3耐受亚硒酸盐的能力。研究表明，低浓度的Se（IV）（〈25mM）对细菌生长有促进作用，高浓度的Se（IV）（〉100raM）起抑制作用。随着Se（IV）浓度的增加，细菌生长的倍增时间延长、增长速率变小、抑制率增大。但细菌耐受Se（IV）的能力可通过不断驯化来有限度的提高。实验得出了其还原耐受亚硒酸盐的浓度高达800mM，抑制细菌生长的半数有效浓度EC50也达到了102．48～150．24mM，可以认为细菌SeRB-1、SeRB-2、SeRB-3为高耐受亚硒酸盐菌。通过透射电镜对细菌的形貌观测发现，在Se（IV）胁迫下，在靠近细菌壁、膜附近位置生成大量的元素硒，这些元素硒的生成可能是细菌为减少Se（IV）毒害而产生的解毒机制；实验中还发现疑似甲基化气体生成，视为其解毒或脱毒的另一机制。因此，本研究成果对于高硒污染区域的微生物修复具有重要的指导意义。This study examined the tolerance of selenite for 3 strains of Bacillus licheniformis SeRB-1 ,Bacillus sp. SeRB-2 and Arthrobacter sp. SeRB-3 from high-Se carbonaceous mudstone. The results demonstrate that cell growth can be stimulated by Se（IV） in lower concentration（less than 25 mM）, but inhibited in higher concentration （over 100 mM）. With the increasing of Se（IV） concentration, the doubling time got longer, rate turned smaller, and percentages of growth inhibition became larger. But, the tolerance of Se（IV） for strains was typically enhanced, through continued domestication and cultivation under an increasing Se（IV） culture. Experiments also show that the concentration of Se（IV）-resistant was as high as 800 mM, while the medium effective concentration of bacterial growth inhibition was also high up to 102. 48 - 150. 24 rnM. Therefore, the strains could be considered as high Se（IV）-resistant bacteria. The TEM studies of bacteria morphology show that large numbers of elemental Se were detected at the cell envelops （near cell wall and membrane） under the Se（IV） stress. Such changes in Se might be one of the detoxification mechanisms of the bacteria. On the other hand, suspected methylation gas was observed during the experiment, which might be recognized as another mechanism for the removal of Se （IV） toxin or detoxification. This research is of great significance for microbial remediation of high-Se polluted areas.

关 键 词：高硒碳质泥岩 亚硒酸盐还原 细菌 四价硒耐受性 高耐受性机理 

分 类 号：P154.381[天文地球—天文学] X144[环境科学与工程—环境科学]