| 摘要 |
PURPOSE:To obtain the titled yeast cell containing a specific amount of lysine and useful as a feed additive for domestic animals such as ruminant, by culturing a yeast in a medium added with a lysine-biosynthesis precursor under aerobic condition. CONSTITUTION:A yeast belonging to Saccharomyces genus, Candida genus, Torulopsis genus, Hansenula genus, Pichia genus, Endomycopsis genus, Debaryomyces genus or Klyveromyces genus, etc., (e.g. Saccharomyces cerevisiae AJ 14590, ATCC 26615) is cultured in a medium composed of glucose, ammonium sulfate, corn steep liquor, MgSO4.7H2O, KH2PO4, etc., and added with a lysine- biosynthesis precursor (e.g. alpha-aminoadipic acid) under aerobic condition at 20-40 deg.C and 3-9pH for 2-5 days. The objective yeast cell for feed obtained by the above process contains >=10% L-lysine per unit weight of dried yeast cell (in terms of L-lysine hydrochloride). When the cell is suspended in a MacDugall buffer liquid and maintained at 39 deg.C for 12hr, the dissolved L-lysine is <=10% of the total L-lysine in the yeast cell. |
