海洋微生物Paenisporosarcina quisquiliarum对Fe的生物矿化过程

为了解海洋微生物的生物矿化作用在大洋铁锰结核形成过程中的意义,选取芽孢八叠球菌作为实验菌株,通过实验室模拟中性有氧环境下的生物矿化实验,测定了Fe生物矿化过程中Fe离子浓度与价态的变化、细菌表面形态与矿物成分的变化。反应过程中,通过与死菌对照组和空白对照组的对比研究,有菌实验组的总Fe浓度、Fe²⁺浓度和Fe³⁺浓度下降最快,尤其是在前24 h。TEM照片显示细菌表面有明显的矿物颗粒生成,对这些矿物颗粒进行EDS分析测定,推测为Fe的氧化物或氢氧化物。实验结果表明,以芽孢八叠球菌为代表的海洋微生物在中性有氧条件下,通过主被动相结合的过程,对Fe产生了明显的矿化作用,揭示了微生物矿化作用对大洋铁锰结核形成的贡献。

Biomineralization of Fe by the marine microorganism Paenisporosarcina quisquiliarum

In order to investigate the role of the biomineralization of marine microorganisms in the formation of oceanic ferromanganese (Fe-Mn) nodules, Paenisporosarcina quisquiliarum was selected for the biomineralization simulation experiment in a neutral aerobic environmental conditions. The changes of Fe ion concentration and speciation, the changes of bacterial surface morphology and mineral composition during the mineralization process were measured. Compared with the dead bacteria control group and the blank control group, the total concentration of Fe and the concentrations of Fe2+/ Fe3+ in the experimental group with bacteria decreased the fastest, especially in the first 24 hours of the reaction process. The TEM and EDS analyses revealed that there were obvious mineral particles formed on the surface of the bacterial cells and these mineral particles were indicated to be Fe oxides or hydroxides. The experimental results implied that under neutral aerobic conditions, the marine microorganisms represented by Paenisporosarcina quisquiliarum had obvious mineralization of Fe through active and passive interaction processes. This study reveals the contribution of microbial mineralization process to the formation of oceanic ferromanganese nodules.