Fed-batch cultivation of bakers' yeast: Effect of nutrient depletion and heat stress on cell composition


Ertugay N., Hamamci H., Bayindirli A.

FOLIA MICROBIOLOGICA, cilt.42, ss.214-218, 1997 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 42 Konu: 3
  • Basım Tarihi: 1997
  • Doi Numarası: 10.1007/bf02818981
  • Dergi Adı: FOLIA MICROBIOLOGICA
  • Sayfa Sayıları: ss.214-218

Özet

The physiology of a commercial strain of bakers' yeast was studied in terms of the cell composition under different growth conditions and of its response to stress. The study comprised fed-batch experiments since this is the system used in bakers' yeast industry. The classical fed-batch fermentation procedure was modified in that the yeast cells were continuously grown to a steady-state at a dilution rate of 0.1/h in order to achieve more or less the same initial starting point in terms of cell composition. This steady-state culture was then switched to fed-batch concomitantly with exposure to stress. The highest amount of trehalose accumulation was achieved when nutrient depletion and heat stress were applied concomitantly. The highest amount of trehalose, 12 %, was attained in cells stressed by both nitrogen depletion and heat stress. The protein content remained constant, although with some oscillations, at a value of 30 % throughout this dual stress experiment.