Synthesis of intracellular cobalt ferrite nanocrystals by extreme acidophilic archaea Ferroplasma thermophilum  

极端嗜酸古菌Ferroplasma thermophilum合成胞内含钴铁纳米颗粒

作　　者：WU Bai-qiang HE Wan-li YANG Bao-jun LIAO Rui ZHOU Yi LIU Yu-ling LIN Mo QIU Guan-zhou WANG Jun 邬柏强;何万里;杨宝军;廖蕤;周祎;刘玉玲;林墨;邱冠周;王军(Key Laboratory of Biohydrometallurgy of Ministry of Education,Central South University,Changsha 410083,China;School of Minerals Processing and Bioengineering,Central South University,Changsha 410083,China)

机构地区：[1]Key Laboratory of Biohydrometallurgy of Ministry of Education,Central South University,Changsha 410083,China [2]School of Minerals Processing and Bioengineering,Central South University,Changsha 410083,China

出　　处：《Journal of Central South University》2020年第5期1443-1452,共10页中南大学学报（英文版）

基　　金：Project(2018JJ1041)supported by the Natural Science Foundation of Hunan,China;Projects(51774332,51934009,U1932129)supported by the National Natural Science Foundation of China。

摘　　要：Ferroplasma thermophilum,a sort of extreme acidophilic archaea,which can synthesize intracellular cobalt ferrite nanocrystals,is investigated in this study.The nanocrystals were analyzed with ultrathin sections and transmission electron microscope,with the size of 20−60 nm,the number of more than 30 in each cell at average,which indicated that F.thermophilum can synthesize intracellular nanocrystals and also belongs to high-yield nanocrystals-producing strain.Intriguingly,the nanocrystals contain ferrite and cobalt characterized by EDS X-ray analysis,suggesting that both cobalt and ferrite are potentially contributed to the formation of nanocrystals.Moreover,under the different energy source culture conditions of FeSO4 and CuFeS2,the size and the morphology of the nanocrystals are different.It was also found that the higher initial Fe availability leads to an induced synthesis of larger nanocrystals and the lower oxidation-reduction potential(ORP)leads to an induced effect on the synthesis of nanocrystals with abnormal unhomogeneous size,which suggested that the higher initial Fe availability and the lower oxidation-reduction potential lead to a higher uptake efficiency of iron ions of F.thermophilum by iron and ORP gradient culture.本文研究一种极端嗜酸古菌Ferroplasma thermophilum合成胞内含铁钴的纳米颗粒。通过冷冻切片和透射电镜发现纳米颗粒的大小在20~60nm,其数目在每个细胞中平均超过30个,这表明Ferroplasma thermophilum不仅可以合成胞内纳米颗粒,还是一种高产菌。更有趣的是,通过EDS X-ray分析表明,纳米颗粒的元素组成包含铁与钴,这表明铁与钴都参与了纳米颗粒的合成。更重要的是,在不同能源物质由硫酸亚铁与黄铜矿的培养下,发现Ferroplasma thermophilum所合成的纳米颗粒大小与形态不同。进一步研究表明,这一现象与培养基中最初铁离子浓度和电位有关,在高初始铁离子浓度培养下,Ferroplasma thermophilum所合成的纳米颗粒较大,低电位导致纳米颗粒形态不均一,原因在于高初始铁离子浓度与低电位促进了Ferroplasma thermophilum铁离子的吸收。我们的研究丰富了磁性细菌的趋磁种类,增加了微生物合成胞内纳米颗粒的多样性,尤其是钴的参与。

关 键 词：Ferroplasma thermophilum cobalt ferrite nanocrystals BIOMINERALIZATION bioleaching extreme acidophilic microorganism 

分 类 号：TB383.1[一般工业技术—材料科学与工程]