Accumulation and species distribution of selenium in Se-enriched bacterial cells of the Bifidobacterium animalis 01

Bifidobacterium animalis 01 (B. animalis 01) could absorb 16.7-39.6% of inorganic selenium in the medium and transform most of it into organic selenium. Most of the organic selenium (50.7-63.0%) was found in the protein fraction, 9.62-18.7% in the polysaccharide fraction, 0.273-0.754% in the nucleic acid fraction, and 20.8-30.9% in other components. Furthermore, the selenium content of different protein extractions was in the following order: Alkaline-soluble protein-bound Se (46.5-53.4%) > Water-soluble protein-bound Se (27.4-30.8%) > Salt-soluble protein-bound Se (7.79-11.9%) > Alcohol-soluble protein-bound Se (not detected). Additionally, the molecular mass of most proteins or protein subunits containing selenium was about 10-20 kDa. Analysis by LC-MS showed that selenomethionine (SeMet) is the major selenocompound in protein. (C) 2008 Elsevier Ltd. All rights reserved.