细菌胞外液生物合成纳米硒的理化性质及抗菌活性研究

Physicochemical properties of selenium nanoparticles biosynthesis from bacterial extracellular extract and its antibacterial activity

本文以一株海洋菌株Bacillussp.Q72的胞外液为还原体系,实现了Se(IV)到纳米硒(SeNPs)的生物转化。利用FTIR、UV-Vis、XRD、SEM、TEM、XPS、拉曼光谱、粒度分析等对生物合成SeNPs的理化性质进行了研究,随后考察了SeNPs的抗菌活性和细胞毒性。结果表明,菌株Bacillus sp.Q72胞外液生物合成的SeNPs为球型,平均粒径为187.6nm,其表面包覆着蛋白质、核酸等生物大分子。SeNPs对金黄色葡萄球菌和铜绿假单胞菌均表现出较好的抑菌活性,同时具有较低的细胞毒性。利用细菌胞外液生物合成纳米硒,避免了利用菌体直接还原在分离过程中的繁琐操作,为SeNPs的生物合成提供了新方法。

In this paper,the extracellular extract of a marine strain Bacillus sp.Q72 was used as the reducing system to achieve the biotransformation of Se(IV)to selenium nanoparticles(SeNPs).The physicochemical properties of biosynthesized SeNPs were inves-tigated by FTIR,UV-Vis,XRD,SEM,TEM,XPS,Raman spectroscopy,particle size analysis,and then the antibacterial activity and the cytotoxicity of SeNPs were investigated.The results showed that SeNPs biosynthesized from the extracellular extract of Bacillus sp.Q72 were spheroid with an average particle size of 187.6nm,The surface of the SENPs was coated with proteins,nucleic acids and other biomolecules.SeNPs showed good antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa with low cytotoxicity.Biosynthesis of SeNPs from bacterial extracellular extract avoids the tedious operation in the separation process of that reducing by the whole cell.It provides a new method for the biosynthesis of SeNPs.