菱锰矿的微生物矿化实验研究  

Experimental study on microbial mineralization of rhodochrosite

作　　者：陈笑夜[1] 陆现彩[1] 刘欢[1] 李娟[1] 朱翔宇[1] 

机构地区：[1]内生金属矿床成矿机制研究国家重点实验室,南京大学地球科学与工程学院,南京210093

出　　处：《南京大学学报（自然科学版）》2013年第6期673-680,共8页Journal of Nanjing University（Natural Science）

基　　金：国家自然科学基金(40930742;41272056);江苏省省基金创新学者攀登项目(BK2010008)

摘　　要：菱锰矿是沉积锰矿的主要矿石矿物类型,有研究表明生物作用有助于菱锰矿的形成和沉积.本文从栖霞山石炭系含锰沉积风化产物中分离获得两株芽孢杆菌属细菌,在使用PCR技术鉴定菌种的基础上,通过模拟实验研究了该菌在含Mn2+溶液中促进锰矿物沉淀的现象.利用X射线衍射分析、扫描电子显微镜和X射线吸收精细光谱等分析方法,研究了细菌参与下形成的富锰沉淀的矿物物相组成.实验结果表明,细菌显著促进了菱锰矿的沉淀,在此基础上进一步探讨了细菌在锰矿化过程中的贡献.本项实验丰富了富锰沉积的微生物成因研究.In general, rhodochrosite is the primary mineral in the manganese ores with sedimentary genesis. Many studies have shown that the mediation of biological activities clearly promote the precipitating of rhodochrosite and in some special environments substantive rhodochrosite is enriched as sedimentary mineral deposits. Traditionally, sedimentary manganese deposits are thought as chemically sedimentary deposit. But, more and more petrological and geochemical evidences support that microbial mineralization plays important roles in this mineralization processes. For disclosing the influences of microorganisms on the precipitating of rhodochrosite, this study carried out a series of imitative experiments. Firstly, two manganese-tolerance strains of Bacillus pumilus and Bacillus megaterium identified using PCR and 16SrRNA techniques, have been isolated from the weathering products of the Carboniferous manganese-enriched strata in Qixiashan, Nanjing, eastern China. Then, the influence of bacteria strains on the mineralization of manganese from Mn2＋-bearing solution have been experimentally investigated. The result show that the promotion on the precipitation of manganese is significantly evident comparing with the control without bacteria. By using X-ray diffraction, scanning electron microscopy, and X-ray absorption fine spectroscopy （XAFS） methods, the mineral composition of the precipitation were identified, and it has been found that rhodochrosite is the main component, which is consistent with XAFS results. In further, the contribution of bacteria on the mineralization of manganese was discussed. The conclusions of this study will enrich the genesis research of sedimentary manganese deposits.

关 键 词：菱锰矿 微生物矿化 次生矿物 栖霞山 

分 类 号：P618.130.1[天文地球—矿床学]