利用地衣芽孢杆菌制备纳米硒能力的研究

Preparation of Nano-Selenium from[WT4"HX]Bacillus licheniformis

生物纳米硒具有低毒、高效的生物活性,易于/被机体吸收、毒性小等特点。为了探讨益生芽孢杆菌制备纳米硒的能力,以地衣芽孢杆菌(Bacillus licheniformis,Bl-001)为研究对象,在改良LB液体培养基中加入一定浓度亚硒酸钠进行液体震荡培养,解析菌株合成纳米硒的基本规律,研究了地衣芽孢杆菌对亚硒酸钠的耐受程度、亚硒酸钠的转化率与纳米硒的产率、纳米硒的提取率与纯度、纳米硒的形貌表征。研究结果表明,地衣芽孢杆菌Bl-001在120μg/mL亚硒酸钠浓度的改良LB液体培养基中培养36 h,亚硒酸钠的转化率为91.52%,纳米硒的产率高达74.83%,提取率为95.62%,纯度为73.43%。利用扫描电镜(SEM)观察纳米硒的形貌,X射线能谱仪(EDS)分析纳米硒的表面元素组成,结果表明,纳米硒呈规则的球状颗粒,粒径在90~200 nm之间,在1.4 keV出现了Se元素的特征峰,其相对含量最高达82.07%,从而更加确定Bl-001所产生的球形颗粒为生物纳米硒。该研究结果可为微生物法转化制备纳米硒提供理论依据。

Biological nano-selenium has low toxicity,high efficiency biological activity,easy to be absorbed by the body,low toxicity and so on.In order to investigate the ability of Bacillus probiotics to produce nano-selenium,Bacillus licheniformis(Bl-001)was taken as the research object,and a certain concentration of sodium selenite was added to the modified LB liquid medium for liquid shock culture,and the basic law of the synthesis of nano-selenium was analyzed.The tolerance degree of Bacillus licheniformis to sodium selenite,the conversion rate of sodium selenite and the yield of nano-selenium,the extraction rate and purity of nano-selenium,and the morphology of nano-selenium were studied.The results showed that when Bacillus licheniformis Bl-001 was cultured in the modified LB liquid medium with 120μg/mL sodium selenite concentration for 36 h,the conversion rate of sodium selenite was 91.52%,the yield of nano-selenium was up to 74.83%,the extraction rate was 95.62%,and the purity was 73.43%.The morphology of nano-selenium was observed by scanning electron microscopy(SEM),and the surface element composition of nano-selenium was analyzed by X-ray energy dispersive spectrometry(EDS).The results showed that nano-selenium was a regular spherical particle with a particle size of 90~200 nm.The characteristic peak of Se element appeared at 1.4 keV,and its relative content was up to 82.07%.Thus,it is more certain that the spherical particles produced by Bl-001 are biological nano selenium.The results can provide a theoretical basis for the preparation of nano-selenium by microbial transformation.