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Biomedical subjects

S Bauer

Publications and source records attributed to S Bauer.

At least 235 records · Page 13Linked to original sources
PubMed1974

Autoradiographic study of mannan incorporation into the growing cell walls of Saccharomyces cerevisiae.

The incorporation of mannan labeled by d-[1-(3)H]mannose into the growing cell walls of Saccharomyces cerevisiae has been followed by means of high-resolution autoradiography. The results show that, in the very first stage of budding, when the shape of the bud is nearly spherical, the new mannan is incorporated uniformly over the whole surface of the emerging bud. Later on, as the bud growth proceeds, the polarized tip growth predominates. In the maturation phase of bud growth, when the size of the bud is about two-thirds that of the mother cell, again a considerable incorporation of the labeled substrate over the whole bud surface was observed. The cell wall of the mother cell remained largely unlabeled. These facts indicate that the ellipsoidal shape of the cell walls in S. cerevisiae is the result of the combination of polarized tip growth and nonpolarized spherical extension.

Autoradiography↗
PubMed1973

Lysis of Saccharomyces cerevisiae with 2-deoxy-2-fluoro-D-glucose, an inhibitor of the cell wall glucan synthesis.

The effect of a synthetic glucose analogue, 2-deoxy-2-fluoro-d-glucose (FG) on growth and glucose metabolism of Saccharomyces cerevisiae was studied. The addition of FG (0.005-0.05%) to a 2% glucose medium resulted in reduction of the initial growth rate and, after several hours, in a complete cessation of the culture growth. These two events were due to extensive lysis of the population which continued long after the period when no more growth was recorded. Electron microscope examination of lysed cells showed that the lysis was a consequence of a dissolution of the cell walls. FG inhibited to a similar extent the initial growth rate and the incorporation of radioactivity from labeled glucose into growing population. The inhibition of radioactivity incorporation from glucose by growing protoplasts was much less. The yeast was found to be extremely FG sensitive whenever the synthesis of new cell wall material was involved. All observations imply that FG interferes mainly with the cell wall formation of S. cerevisiae. A comparison of the FG effects on metabolic activity of protoplasts, simultaneous secretion of mannan-proteins into the growth medium, and the formation of glucan fibrils on the surface of protoplasts demonstrated that the cell wall glucan synthesis is the most FG-sensitive process and evidently the growth-limiting factor in intact cells. FG-resistant cells were selected during growth experiments. They exhibited an altered mode of cell division when grown in the presence of FG.

Autolysis↗