[Riboflavin transport in cells of riboflavin-dependent yeast mutants]

Riboflavin was transported at a high rate into yeast cells of Pichia guilliermondii and Schwanniomyces occidentalis mutants capable of growth in a medium containing low concentrations of riboflavin, and having multiple susceptibility to some antibiotics and antimetabolites. Sucrose and sodium azide inhibited transport of riboflavin. Other riboflavin dependent mutants of Pichia guilliermondii, Pichia ohmeri, Torulopsis candida, and Saccharomyces cerevisiae, also growing in media containing low concentrations of riboflavin, were not capable of its active transport.