[Effect of increased temperatures on RNA and protein synthesis in the cells of a synchronous Candida utilis culture]

Abstract

The rate of incorporation of labeled precursors for RNA ([14C]uracil) and protein ([14C]DL-leucine) into the cells of the synchronous culture of Candida utilis VKMY-1668 (the optimum temperature of growth, 31--32 degrees C) was studied as a function of different temperatures (28, 31, 32, 34, 36, 38, and 41 decrees C). The yeast was grown on a simple mineral medium containing glycerol. RNA synthesis was found to be more susceptible to elevated temperature than protein synthesis: the maximum rate of incorporation was registered at 32--34 degrees C for [14C]DL-leucine and only at 32 degrees C for [14C]uracil (the rate of its incorporation at 34 degrees C decreased by 50% as compared to that at 32 degrees C). The rate of incorporation of [14C]uracil at 34 degrees C reached 100% (the rate at 32 degrees C) when yeast autolysate was added to the medium, and 75 and 70%, respectively, upon the addition of DL-methionine or Mg2+ (as compared to 50% without them).