Journal of Industrial Microbiology

, Volume 14, Issue 6, pp 440–450

Chemical and cytological changes during the autolysis of yeasts

  • Tatang Hernawan
  • Graham Fleet

DOI: 10.1007/BF01573955

Cite this article as:
Hernawan, T. & Fleet, G. Journal of Industrial Microbiology (1995) 14: 440. doi:10.1007/BF01573955


Cell suspensions ofSacharomyces cerevisiae, Kloeckera apiculata andCandida stellata were autolyzed in phosphate buffer, pH 4.5, for up to 10 days. Cell dry weights decreased by 25–35% after 10 days. Based on initial cell dry weight, the soluble autolysate consisted of: carbohydrate (principally polysaccharide) 3–7%; organic acids 3–6%; protein 12–13%; free amino acids 8–12%; nucleic acid products 3–5%; and lipids 1–12%. The main organic acids in autolysates were propionic, succinic and acetic and the main amino acids were phenylalanine, glutamic acid, leucine, alanine and arginine. Approximately 85–90% of cellular RNA and 25–40% of cellular DNA were degraded during autolysis. Both neutral lipid and phospholipid components were degraded, with neutral lipids but not phospholipids being found in autolysates. Scanning and transmission electron micrographs showed retention of cell wall structure and shape during autolysis, but there was extensive intracellular disorganization withinS. cerevisiae andC. stellata. There were differences in the autolytic behavior ofK. apiculata compared withS. cerevisiae andC. stellata.

Key words

YeastsAutolysisSaccharomyces cerevisiaeKloeckera apiculataCandida stellata

Copyright information

© Society for Industrial Microbiology 1995

Authors and Affiliations

  • Tatang Hernawan
    • 1
  • Graham Fleet
    • 1
  1. 1.Department of Food Science and TechnologyThe University of New South WalesSydneyAustralia