Enrichment of selenium and its selenium species analysis in Bifidobacterium bifidum BGN4

Abstract

Selenium is a trace element essential for human health that has received considerable attention given its nutritional value. In this research, to solve the poor selenium tolerance of lactic acid bacteria (LAB) and to select a strain with both high selenium uptake efficiency and the ability to transform inorganic selenium into an organic form, five strains of LAB were subjected to an experiment. The total amount of selenium was quantified using an inductively coupled plasma-atomic emission spectrometer (ICP-AES). Selenium species were separated by anion-exchange chromatography and analyzed by inductively coupled plasma-mass spectrometry (ICP-MS). The reduction of bacterial cell mass was solved with an adjustment of the selenium addition time (12 h after incubation), and Bifidobacterium bifidum BGN4 was found to be the most potent selenium-enriched strain. The results showed that selenomethionine was the main organic selenium in selenium-enriched B. bifidum BGN4. Considering that B. bifidum BGN4 is a well-known probiotic strain with clinically proven beneficial effects, selenium-enriched B. bifidum BGN4 may provide dual healthy functions as a daily supplement of selenium and for the regulation of intestinal bacteria.