The efflux of potassium from yeast cells into a potassium free medium

✍ Scribed by Rothstein, A. ;Bruce, M.

• Publisher: Wiley (John Wiley & Sons)
• Year: 1958
• Tongue: English
• Weight: 708 KB
• Volume: 51
• Category: Article
• ISSN: 0095-9898
• DOI: 10.1002/jcp.1030510310

✦ Synopsis

The movements of potassium into and out of the yeast cell have been extensively investigated (see reviews of Rothstein, '55, and Conway, '55). However, nearly all of the measurements represent the net movements of potassium based on chemical analysis, with individual contributions of influx and efflux to the net effect determined in only a few cases, by the use of isotope technique with K42,. The first isotope study (Hevesy and Nielsen, '41) revealed that in rapidly fermenting yeast a rapid exchange of K+ takes place in addition to a rapid net uptake of K' , whereas in slowly fermenting yeast, both processes are markedly diminished. I n yeast without substrate, the K-exchange is exceedingly slow if 0, is excluded, but proceeds at an appreciable rate if 0, is present (Conway, '54; Rothstein, '56).

Recently, the K-efflux and K-influx in fermenting yeast have been determined by the cell column technique, which allows measurements of K-uptake and exchange at a constant potassium concentration (Rothstein and Bruce, '58). With K-free media, the K-eBux proceeds at a constant rate. With a high K-medium, the rate of influx is very much higher than the rate of efflux and is therefore the determining factor in net This paper is based on work performed under contract with the U.S. Atomic Energy Commission a t the University of Rochester Atomic Energy Project, Rochester, N. Y.