Active transport of magnesium across the yeast cell membrane.

Analy8i8 of magnesium, potassium and sodium. The methods used were the same as those described in the preceding paper (Conway & Duggan, 1958). Procedure. Fresh baker's yeast (supplied by the Cork Yeast Co.), was twice washed. A portion (1 g.) of the yeast washed and packed by centrifuging was suspended in 20 vol. of a medium containing 5% (w/v) of glucose and 200 mM-magnesium acetate (or chloride) and fermented for 2 hr. or longer. Before the analytical determinations all samples were washed twice in tap water after centrifuging.