Abstract
SUMMARY Induction of viable protoplasts of both haploid and diploid vegetative cells of Schizosaccharomyces octosporus without added enzyme was best achieved in Sabouraud dextrose broth plus 1.2-1.8 M MgSO4 and 1.5-3.0 mg of 2-deoxy-d-glucose for each 100 ml of medium. Neither the addition of MgSO4 alone, nor of 2DG alone, induced protoplast formation in any medium. Although S. octosporus is a fission yeast, the protoplasts bud freely, but their fusion has not been observed.