Growth characteristics of fusants by protoplast fusion between the thermotolerant yeast, Kluyveromyces marxianus, and the starch-assimilating yeast, Schwanniomyces occidentalis.

Intergeneric fusants were obtained by protoplast fusion between the thermotolerant yeast, Kluyveromyces marxianus, and the starch-assimilating yeast, Schwanniomyces occidentalis. Two thermotolerant fusants growing at 40 degrees C were screened on the medium containing soluble starch. These fusants showed weak growth in a soluble starch medium and the production of a little amylase. The carbon source assimilation and the chromosome composition of the fusants were similar to those of the K. marxianus parent. However, a chromosomal difference from K. marxianus was recognized in the fusants. These results show the possibility that the fusants are amylase-producing strains rearranged from K. marxianus.