Growth Characteristics of Rhoodotorula sp. Y-55 on Ethanol, Acetic acid, and Acetaldehyde Substrates

Ethanol, Acetic acid, Acetaldehyde 기질에서의 Rhoodotorula sp. Y-55의 증식 특징

The growth characteristics of Rhodotorula sp. Y-55 were examined on minimal medium containing ethanol, acetic acid or acetadehyde as a sole carbon source by batch culture. The increased concentration of substrate reduced overall growth yield and prolonged lag time. The specific growth rate of the yeast was changed, depending upon the initial concentrations of ethanol and acetaldehyde during the exponential period, but was constant on acetic acid without regard to the initial substrate concentrations, giving a value of 0.l07h-1. The highest ${\mu}$ value was obtained on ethanol and acetadehyde substrates and the respective values were 0.270 at 20g/L and 0.041h-1 at 0.2g/L. The maximum overall growth yields were appeared to be 32.6% for ethanol of 10g/L, 25.6% for acetic acid of 20g/L, and 45% for acetaldehyde of 0.2g/L. The respective cellular contents of crude protein and nucleic acids were determined to be 41.5 and 4.9wt% on ethanol and 40.2 and 4.7wt% at the concentration revealing maximal growth yield.

Rhodotorula sp. Y -55 효모의 중식특성을 etha nol, acetic acid 또는 acetaldehyde 상에서 batch culture로 조사하였다. 기질농도가 중가함에 따라 중식수율이 감소하고 유도기가 연장되었다. 비성장속도(${\mu}$)는 지수기에서 ethanol과 acetaldehyde의 초기농도에 따라 변화하였으나 acetic acid는 이와 상관이 없었으며 그 값은 $O.107h^{-1}$로 나타났다. 최대 비성장속도는 20g/L의 ethanol에서 $O.270h^{-1}$, O.2g/L의 acetaldehyde에서 $O.041h^{-1}$이었다. 또 최대 중식수융은 109/L의 ethanol에서 32.6%, 20g/L의 a acetic acid에서 25.6%와 O.2g/L의 acetaldehyde 에서 45%였다. 세포내 조단백질과 핵산 함량은 e­t thanol상에서 각각 41.5wt%와 4.9wt %였고 acetic acid상에서는 각각 40.2wt %와 4.7wt%로 나타났다.