金属离子诱导Trichoderma sp.WL-Go合成纳米金特性研究

生物法合成纳米金是一种环境友好且经济高效的合成途径,受到广泛关注.普遍认为微生物合成纳米金是通过胞外分泌生物大分子而实现的一种自发脱毒过程.同时,相关研究表明低浓度的重金属离子对菌株胞外酶的活性会产生一定的影响,进而会对菌株合成纳米金的能力产生影响.基于此,本研究选择一株前期筛选得到的真菌Trichoderma sp. WL-Go,探究不同金属离子诱导菌株对其合成的纳米金特性的影响.结果表明,经Co~(2+)、Al~(3+)、Zn~(2+)、Sn~(2+)、Ni~(2+)等金属离子诱导后,菌株WL-Go合成纳米金的能力均有所提升,而Pb~(2+)、Cu~(2+)、Fe~(3+)与对照组相比,其合成的纳米金浓度及转化率都无明显变化.此外,Co~(2+)诱导菌株合成的纳米金呈现肉眼可见的团簇状,发生明显的团聚现象.本实验还考察了生物合成纳米金对4-硝基苯酚还原的催化特性,结果表明,Sn~(2+)和Pb~(2+)的诱导使菌株WL-Go合成的纳米金催化速率得到明显提升,而其他金属离子均有所抑制.最后选取革兰氏阳性菌Arthrobacter sp. W1和革兰氏阴性菌Escherichia coli BL21 (DE3)验证了不同金属离子诱导后合成的纳米金均具有良好的生物相容性.综上,本研究为对于拓宽纳米金的工业化应用前景有着重要意义.

The biosynthesis of gold nanoparticles by Trichoderma sp. WL-Go induced by different metal ions

Biosynthesis of gold nanoparticles has been considered to be an environmentally friendly, economical and efficient synthetic route, which has attracted increasing attentions in recent years. It is generally believed that the synthesis of AuNPs by microorganisms is a spontaneous detoxification process through some biological macromolecules. Previous studies have shown that some heavy metal ions could affect the extracellular enzyme activity of the microorganism and its ability to synthesize AuNPs. Therefore, in this study, we chose the fungus Trichoderma sp. WL-Go to explore the effects of different metal ions on the AuNPs synthesis. The results show that Co²⁺, Al³⁺, Zn²⁺, Sn²⁺ and Ni²⁺ could promote the synthesis of AuNPs, while there were no significant changes in the concentration and transformation of AuNPs synthesized by Pb²⁺, Cu²⁺ and Fe³⁺-induced strains. In addition, AuNPs synthesized by Co²⁺-induced strain exhibited obvious agglomeration. Result also shows that the catalytic properties of AuNPs synthesized by strains WL-Go induced with Sn²⁺ and Pb²⁺ were improved. Finally, Gram-positive bacteria Arthrobacter sp. W1 and Gram-negative bacteria Escherichia coli BL21 (DE3) were selected, and further proved that the AuNPs synthesized by different metal ions induced WL-Go strains exhibited good biocompatibility. Overall, this study provides new insights into the potential industrial application of AuNPs.