富硒双歧杆菌中硒的赋存形态及分布

Selenium Speciation in Selenium-enriched Bifidobacterium

研究富硒动物双歧杆菌01中硒的赋存形态和分布。对动物双歧杆菌01进行富硒培养,然后从富硒菌体中分离核酸、多糖和蛋白质,并应用SDS-聚丙烯酰胺凝胶电泳分离富硒菌体中的硒蛋白组分,采用氢化物原子吸收(HG-AAS)法测定硒含量。结果表明,动物双歧杆菌01能够吸收16.7%-39.6%的无机硒并将其大部分转化为有机硒;蛋白硒是富硒动物双歧杆菌01中硒的主要赋存形态,有机硒在蛋白质、多糖和核酸中的分布依次为:蛋白硒>多糖硒>核酸硒;在蛋白硒中,硒主要分布在分子量不超过20ku的蛋白或肽链中。

Selenium speciation in selenium -enriched Bifidobacterium animalis 01 （B. animalis 01 ） has been studied. Firstly, B. animalis 01 accumulated inorganic selenium from culture medium. Secondly, nucleic acid, polysaccharide, and proteins were separated from Se-enriched cells respectively. Finally, Protein was separated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis （SDS-PAGE）. The selenium concentration of tested samples was determined by hydride generation-atomic absorption spectrometry （HG-AAS）. The results showed that B. animalis 01 could absorb 16.7% - 39.6% of inorganic selenium in the medium and transform most of it into organic selenium. The proteins in Se-enriched B. animalis 01 showed the strongest ability to incorporate selenium. The organic selenium content of the protein, polysaccharide and nucleic acid extractions was in the following order： protein-bound Se 〉 polysaccharide-bound Se 〉 nucleic acid-bound Se. In the proteins containing selenium, the molecular mass of most proteins or protein subunits containing selenium was about 10 -20 ku