关键词: 纳米硒, 阿氏芽孢杆菌, 解淀粉芽孢杆菌, 凝结芽孢杆菌

Abstract: Nano-selenium is widely used in various fields because of its easy absorption, low toxicity, anti-tumor, anti-oxidation and enhancing immunity, etc. In order to study the ability of different probiotic Bacillus to prepare nano-selenium, taking Bacillus aryabhattai SI9, Bacillus amyloliquefaciens AT34 and Bacillus coagulans LB-9 as research objects, the ability of transforming Na₂SeO₃ into nano-selenium was compared, and the nano-selenium particles prepared by them were characterized by morphology and content determination. The results showed that B. aryabhattai SI9 had the strongest ability to produce nano selenium, followed by B. amyloliquefaciens AT34 and B. coagulans LB-9. With the increase of Na2SeO3 concentration, the growth of three strains was inhibited; when Na₂SeO₃ concentration was 200 μg·mL^-1, the nano-selenium yields of three strains were 48.3%, 36.3%, 34.8%, the extraction rates were 96.9%, 95.0% and 94.0%, respectively; the purity was 73.2%, 78.1% and 89.4%, respectively; and the conversion rates of Na₂SeO₃ were all 100%. It was showed that the sizes of selenium nanoparticles extracted by the three strains were 70～500 nm under field emission scanning electron microscopy (SEM). The present research could provide theoretical support for the preparation of nano-selenium by microbial transformation.

Key words: nano selenium, Bacillus aryabhattai, Bacillus amyloliquefaciens, Bacillus coagulans