The regulation of aerobic polysaccharide synthesis in resting cells of Saccharomyces cerevisiae

1969 ◽  
Vol 66 (1) ◽  
pp. 59-62 ◽  
Author(s):  
C. J. Barwell ◽  
R. V. Brunt
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Resting Cells ◽  
Polysaccharide Synthesis

Net synthesis of sterols in resting cells of Saccharomyces cerevisiae

1954 ◽  
Vol 13 ◽  
pp. 591 ◽  
Author(s):  
Harold P. Klein ◽  
Norman R. Eaton ◽  
John C. Murphy
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Resting Cells

Mechanisms of appearance of the Pasteur effect in Saccharomyces cerevisiae: inactivation of sugar transport systems

1982 ◽  
Vol 152 (1) ◽  
pp. 19-25
Author(s):  
R Lagunas ◽  
C Dominguez ◽  
A Busturia ◽  
M J Sáez
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Nitrogen Source ◽  
Nitrogen Starvation ◽  
Sugar Transport ◽  
Regulatory Mechanisms ◽  
Transport Systems ◽  
Resting Cells ◽  
Catabolic Pathway ◽  
Pasteur Effect ◽  
Do So

Saccharomyces cerevisiae does not show a noticeable Pasteur effect (activation of sugar catabolism by anaerobiosis) when growing with an excess of sugar and nitrogen source, but it does do so after exhaustion of the nitrogen source in the medium (resting state). We have found that this different behavior of growing and resting S. cerevisiae seems due to differences in the contribution of respiration to catabolism under both states. Growing S. cerevisiae respired only 3 to 20% of the catabolized sugar, depending on the sugar present; the remainder was fermented. In contrast, resting S. cerevisiae respired as much as 25 to 100% of the catabolized sugar. These results suggest that a shift to anaerobiosis would have much greater energetic consequences in resting than in growing S. cerevisiae. In resting S. cerevisiae anaerobiosis would strongly decrease the formation of ATP; as a consequence, various regulatory mechanisms would switch on, producing the observed increase of the rate of glycolysis. The greater significance that respiration reached in resting cells was not due to an increase of the respiratory capacity itself, but to a loss of fermentation which turned respiration into the main catabolic pathway. The main mechanism involved in the loss of fermentation observed during nitrogen starvation was a progressive inactivation of the sugar transport systems that reduced the rate of fermentation to less than 10% of the value observed in growing cells. Inactivation of the sugar transports seems a consequence of the turnover of the sugar carriers whose apparent half-lives were 2 to 7 h.

EFFECTS OF VEGETABLE TANNINS ON GLUCOSE OXIDATION BY VARIOUS MICROORGANISMS

1966 ◽  
Vol 12 (4) ◽  
pp. 787-794 ◽  
Author(s):  
J. Basaraba
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Energy Source ◽  
Pseudomonas Fluorescens ◽  
Glucose Oxidation ◽  
Glucose Utilization ◽  
Resting Cells ◽  
E Coli ◽  
Vegetable Tannins ◽  
Chestnut Wood

The effects of purified tannin preparations of chestnut wood and of wattle bark on the respiration of resting cells of microorganisms were measured in a Warburg apparatus. Tannins were tested at 0.5% (w/v) concentration alone and in mixtures with glucose which provided energy for the microorganisms. In presence of the chestnut and wattle tannins, the exogenous respiration of Asotobacter vinelandii was reduced by 50 and 85% and that of Escherichia coli by 40 and 20%, respectively; respiration of Azatobacler chroococcum was completely inhibited by either tannin. Glucose oxidation by Rhizobium melioti, Rhisobium sp., and Saccharomyces cerevisiae was inhibited by tannins to small degrees. Tannins had no effect on glucose utilization by Rhodotorula sp. and Pseudomonas fluorescens. A. vinelandii, E. coli, and P. fluorescens utilized tannins, especially wattle, as an energy source.

Ultrastructure of Melosira resting cell rejuvenation

1984 ◽  
Vol 42 ◽  
pp. 734-735
Author(s):  
C. E. M. Bourne ◽  
L. Sicko-Goad
Keyword(s):  
Electron Microscopy ◽  
Lake Michigan ◽  
Light And Electron Microscopy ◽  
Resting Cells ◽  
Planktonic Diatoms ◽  
Resting Cell ◽  
Vegetative Survival ◽  
Cytological Changes ◽  
Recent Attention ◽  
Freshwater Diatom

Much recent attention has been focused on vegetative survival forms of planktonic diatoms and other algae. There are several reports of extended vegetative survival of the freshwater diatom Melosira in lake sediments. In contrast to those diatoms which form a morphologically distinct resistant spore, Melosira is known to produce physiological resting cells that are indistinguishable in outward morphology from actively growing cells.We used both light and electron microscopy to document and elucidate the sequence of cytological changes during the transition from resting cells to actively growing cells in a population of Melosira granulata from Douglas Lake, Michigan sediments collected in mid-July of 1983.

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