Vs. Javadekar et al., INDUSTRIAL YEAST-STRAIN IMPROVEMENT - CONSTRUCTION OF A HIGHLY FLOCCULANT YEAST WITH A KILLER CHARACTER BY PROTOPLAST FUSION, Journal of industrial microbiology, 15(2), 1995, pp. 94-102
Conditions were optimized for rapid release and improved regeneration
of protoplasts of saccharomyces cerevisiae NCIM 3458. Rapid protoplast
release was also obtained with representatives of several other yeast
genera under the modified conditions of treatment. The application of
the procedure in construction of a highly flocculent saccharomyces ce
revisiae with a killer character is described. Fusion was effected bet
ween UV-killed protoplasts of S. cerevisiae NCIM 3578 with a killer ch
aracter and live protoplasts of the highly flocculent S. cerevisiae NC
IM 3528 in the presence of polyethylene glycol (PEG) 6000. Fusants wer
e selected using benomyl resistance as marker, the killer toxin produc
er rather than the highly flocculent yeast being resistant to the fung
icide at a concentration of 100 mu g ml(-1). Fusants were also charact
erized by their DNA contents, capacity for ethanolic fermentation of m
olasses sugar and levels of invertase, alcohol dehydrogenase and pyruv
ate decarboxylase activities.