Distinctly Different Characteristics of Flocculation in Yeast1
H. Nishihara, 2, 3 K. Miyake, 2 and Y. Kageyama 2
1 A part of the contents of this paper was communicated as a poster presentation at the 10th International Yeast Symposium held in Arnhem, Netherlands in 2000.
2 Department of Chemistry, Faculty of Education, Kagawa University, 1-1 Saiwai-cho, Takamatsu 760-8522, Japan.
3 Corresponding author: E-mail: nishihar@ed.kagawa-u.ac.jp
J. Inst. Brew. 108(2), 187-192, 2002 | VIEW ARTICLE
ABSTRACT
Flocculation of cells of S. cerevisiae NCYC 1109 and
S. cerevisiae NCYC 234 was studied. Both cells flocculated 48 h after inoculation although the cells grown for only 20 h were non-flocculent. EDTA inhibited the flocculation of cells of
S. cerevisiae NCYC 1109 and Ca 2+ enhanced it. Protein-denaturants, D-mannose and D-glucose depressed the flocculation of cells of NCYC 1109. Treatment with proteolytic enzymes, photo-irradiation in the presence of methylene blue or periodate oxidation caused a loss of the floc-forming ability of the cells of NCYC 1109. On the contrary, the flocculation of cells of NCYC 234 was not affected by EDTA and Ca 2+. Protein-denaturants and monosaccharides did not inhibit the flocculent ability of cells of NCYC 234. Neither proteolytic enzyme treatments, photo-irradiation in the presence of methylene blue nor periodate oxidation, deprived the cells of NCYC 234 of the floc-forming ability. Cycloheximide repressed induction of the floc-forming ability of growing cells of NCYC 1109 significantly but not of growing cells of NCYC 234. These results suggest that the mechanisms of flocculation of NCYC 1109 and NCYC 234 are quite different.
Key words:
Chemical modification, flocculation, intercellular interaction,
Saccharomyces cerevisiae, yeast.
Publication no. G-2002-0610-06R ©2002 The Institute & Guild of Brewing