[Effect of raised temperatures on the protein and RNA synthesis rate in yeasts]

The rates of incorporation of labelled precursors of protein (14C-DL-leucine) and RNA (14C-uracil) into the cells of synchronous yeast cultures of Pichia membranaefaciens, Hansenula anomala, Saccharomyces cerevisiae and Saccharomyces (fabospora) fragilis were studied at different temperatures. Synthesis of RNA and then of protein was inhibited in H. anomala if the temperature was increased above the optimal one. This is manifested even more distinctly in Sacch. cerevisiae and P. membranaefaciens. In the thermotolerant yeast Sacch. fragilis, the incorporation of 14C-uracil was inhibited at temperatures above 40 degrees C while the rate of protein synthesis did not decrease.