Yeast Growth and Glycerol Formation.

Nordström, Kurt; Bagger, Sven; Sillén, Lars Gunnar; Kulonen, E.; Brunvoll, J.; Bunnenberg, E.; Djerassi, Carl; Records, Ruth

doi:10.3891/acta.chem.scand.20-1016

Cited by 54 publications

(43 citation statements)

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“…As the summation of all the flux control coefficients for a specific pathway will be 1.0, GPDH will thus have a major impact on the flux to glycerol. amounts (14). The enhanced need for NADH during the conditioning in 0.7 M NaCl was partly accounted for by an increased rate of acetate production (Fig.…”

Section: Resultsmentioning

confidence: 95%

Roles of glycerol and glycerol-3-phosphate dehydrogenase (NAD+) in acquired osmotolerance of Saccharomyces cerevisiae

1989

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In a cell culture of Saccharomyces cerevisiae exponentially growing in basal medium, only 0.02% of the cells were osmotolerant, i.e., survived transfer to medium containing 1.4 M NaCl. Short-time conditioning in 0.7 M NaCl medium transformed the whole population into an osmotolerance phenotype. During this conditioning, the rate of formation of glycerol, the main compatible solute in S. cerevisiae, increased threefold and the specific activity of glycerol-3-phosphate dehydrogenase (NAD+) (GPDH) (EC 1.1.1.8) was enhanced sixfold. The apparent flux control coefficient for GPDH in the formation of glycerol was estimated to be 0.6. Glycerol production was also favored by regulated activities of alcohol dehydrogenase (EC 1.1.1.1) and aldehyde dehydrogenase [NAD(P)]+ (EC 1.2.1.5). About 50% of the total glycerol produced during conditioning in 0.7 M NaCl was retained intracellularly, and the increased glycerol accumulation was shown to be not merely a result of enhanced production rate but also of increased retention of glycerol. Washing the cells with solutions of lower salinities resulted in loss of glycerol, with retained levels proportional to the concentration of NaCl in the washing solution. Cycloheximide addition inhibited the development of acquired osmotolerance and conditioned cells washed free of glycerol retained a high degree of osmotolerance, which indicate that protein synthesis was required to establish the osmotolerance state.

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Section: Resultsmentioning

confidence: 95%

Roles of glycerol and glycerol-3-phosphate dehydrogenase (NAD+) in acquired osmotolerance of Saccharomyces cerevisiae

1989

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“…One such potential mechanism would be glycerol production, which is an ATP-consuming reaction. The rationale for glycerol production under anaerobic conditions is to maintain a cytoplasmic redox balance (27) by consuming the excess NADH formed during biosynthesis, mainly amino acid synthesis (1). Indeed, it did seem as if the cells used glycerol formation for consumption of unnecessary ATP under some but not all conditions.…”

Section: Discussionmentioning

confidence: 99%

Glycolytic flux is conditionally correlated with ATP concentration in Saccharomyces cerevisiae: a chemostat study under carbon- or nitrogen-limiting conditions

et al. 1997

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Anaerobic and aerobic chemostat cultures of Saccharomyces cerevisiae were performed at a constant dilution rate of 0.10 h ؊1 . The glucose concentration was kept constant, whereas the nitrogen concentration was gradually decreasing; i.e., the conditions were changed from glucose and energy limitation to nitrogen limitation and energy excess. This experimental setup enabled the glycolytic rate to be separated from the growth rate. There was an extensive uncoupling between anabolic energy requirements and catabolic energy production when the energy source was present in excess both aerobically and anaerobically. To increase the catabolic activity even further, experiments were carried out in the presence of 5 mM acetic acid or benzoic acid. However, there was almost no effect with acetate addition, whereas both respiratory (aerobically) and fermentative activities were elevated in the presence of benzoic acid. There was a strong negative correlation between glycolytic flux and intracellular ATP content; i.e., the higher the ATP content, the lower the rate of glycolysis. No correlation could be found with the other nucleotides tested (ADP, GTP, and UTP) or with the ATP/ADP ratio. Furthermore, a higher rate of glycolysis was not accompanied by an increasing level of glycolytic enzymes. On the contrary, the glycolytic enzymes decreased with increasing flux. The most pronounced reduction was obtained for HXK2 and ENO1. There was also a correlation between the extent of carbohydrate accumulation and glycolytic flux. A high accumulation was obtained at low glycolytic rates under glucose limitation, whereas nitrogen limitation during conditions of excess carbon and energy resulted in more or less complete depletion of intracellular storage carbohydrates irrespective of anaerobic or aerobic conditions. However, there was one difference in that glycogen dominated anaerobically whereas under aerobic conditions, trehalose was the major carbohydrate accumulated. Possible mechanisms which may explain the strong correlation between glycolytic flux, storage carbohydrate accumulation, and ATP concentrations are discussed.The yeast Saccharomyces cerevisiae is an organism with a remarkable metabolic flexibility. It is one of the few yeasts which are able to grow fermentatively under strictly anaerobic conditions (40). It is also capable of using an entirely respiratory metabolism when sufficient oxygen is available. These two types of catabolism are, however, often used simultaneously. Respiration is the more efficient pathway in terms of ATP production per substrate utilized, but apparently with a limited capacity for high rates compared with fermentation. For instance, by gradually increasing the dilution rate in chemostat cultures, it has been demonstrated that S. cerevisiae uses a strictly respiratory metabolism at low dilution rates whereas at high dilution rates, fermentation is used in addition to respiration (19,29,41).The rates of energy production in these catabolic pathways are not always correlated with the anabolic ene...

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“…The value for yeast was taken from ref. 19 in which it was concluded that 1 mole of cell-C was derived from 0-38 moles of a Cs-unit and 0>24 moles of CO2. The formula for the ash-free yeast was calculated to be CH,.^O0.«, N0.18 Pp-oo* So.ooa.…”

Section: Resultsmentioning

confidence: 99%

“…19 The formation of glycerol is the means by which Saccharomyces cercvisiac maintains the redox balance under anoxidative conditions. Many micro-organisms are able to grow in the absence of oxygen.…”

Section: Resultsmentioning

confidence: 99%

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