On the formation of glycogen and trehalose in baker's yeast

Grba, Slobodan; Oura, Erkki; Suomalainen, Heikki

doi:10.1007/bf01385443

Cited by 47 publications

(20 citation statements)

References 16 publications

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“…Our results indicate that trehalose synthesis is delayed until trehalase is almost inactive. It has been found that trehalose is formed at the expense of glycogen during the drying of baker's yeast [29]. We found that the rise of trehalose can account for 50% of the glycogen breakdown suggesting that, in the culture, a similar process may take place.…”

Section: Discussionmentioning

confidence: 61%

Changes in the concentration of cAMP, fructose 2,6‐bisphosphate and related metabolites and enzymes in Saccharomyces cerevisiae during growth on glucose

François

Eraso

Gancedo

1987

European Journal of Biochemistry

117

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Changes in the concentration of several metabolites and enzymes related to carbohydrate metabolism were measured during the growth of Saccharomyces cerevisiae on a mineral medium containing glucose as the limiting nutrient. When about 50% of the original glucose was used the exponential phase ended and the culture entered a 'transition' phase before the complete exhaustion of glucose. In this transition phase several metabolic changes occurred. CAMP, that decreased along growth, reached a constant value of about 0.7 nmol/g dry weight. A pronounced drop in fructose-6-phosphate-2-kinase activity and in the concentration of fructose 2,6-bisphosphate and fructose 1,6-bisphosphate was observed accompanied by a less marked decrease in hexose monophosphates. Trehalase activity also dropped and reached a minimal value at the onset of the stationary phase when synthesis of trehalose began. Glycogen concentration and glycogen synthase activity increased sharply during the transition phase. Plasma membrane ATPase began to increase at the middle of the exponential phase and then, coincident with the glucose exhaustion, a 90% decrease in the measurable activity was observed.Growth of Saccharomyces cerevisiae on glucose elicits a well-known pattern of enzymes and metabolites [l, 21. In the last years some observations have been reported that suggest that this pattern may not be constant during growth. For example a decrease in RNA and protein synthesis is observed well in advance of glucose exhaustion [3]. Also glycogen accumulation begins when about half of the original glucose remains in the culture irrespective of the initial concentration of the sugar [4].Recently cAMP and fructose 2,6-bisphosphate [Fru(2,6)-P2] have received considerable attention as possible 'organizers' of carbohydrate metabolism in yeast [5, 61. In order to provide more experimental data to disprove or support this idea we initiated a systematic investigation of the concentrations of these compounds and some other metabolites and enzymes related to carbohydrate metabolism during growth of yeast on glucose. The results of our study show that exponential growth ceases when glucose is still present in the culture and that important metabolic changes occur in the transition phase between the exponential and stationary phase of growth. MATERIALS AND METHODS Growth conditionsSaccharomyces cerevisiae X2180 was grown at 30°C in a mineral medium [7] using NaCl instead of the original sodium citrate. The pH of the medium was adjusted to 5.5 with KOH. Glucose was added after sterilization at a final concentration of 2%. The media were inoculated with yeasts grown to the stationary phase on a medium containing 2% glucose, 1% yeast extract and 1 YO bactopeptone. The initial cell concentration was about lo5 cells/ml. Growth was followed by measuring the turbidity of the culture at 660 nm and the corresponding dry weight was calculated from a calibration curve of dry weight versus absorbance (Fig. 1). This curve was constructed in the same conditions as the subseque...

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Section: Discussionmentioning

confidence: 61%

Changes in the concentration of cAMP, fructose 2,6‐bisphosphate and related metabolites and enzymes in Saccharomyces cerevisiae during growth on glucose

François

Eraso

Gancedo

1987

European Journal of Biochemistry

117

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“…If trehalose is playing only a minor role in yeast desiccation tolerance, what function can we attribute to it? Trehalose was originally regarded as a storage carbohydrate in yeast (Thevelein, 1984;Wiemken, 1990), but it has now been implicated in resistance to heat, freezing, toxic chemicals, elevated osmolarity, high pressure and oxidation, as well as desiccation (Grba et al, 1975;Attfield, 1987;Gadd et al, 1987;Hottiger et al, 1987;Mackenzie et al, 1988;De Virgilio et al, 1994;Iwahashi et al, 1997;Hounsa et al, 1998;Benaroudj et al, 2001). The importance of trehalose in these various stress responses is still unclear, however (Panek et al, 1990).…”

Section: Discussionmentioning

confidence: 99%

Intracellular trehalose is neither necessary nor sufficient for desiccation tolerance in yeast

Ratnakumar

Tunnacliffe

2006

FEMS Yeast Research

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Trehalose is thought to be important for desiccation tolerance in a number of organisms, including Saccharomyces cerevisiae, but there is limited in vivo evidence to support this hypothesis. In wild-type yeast, the degree of desiccation tolerance has been shown previously to increase in cultures after diauxic shift and also in exponential-phase cultures after exposure to heat stress. Under both these conditions, increased survival of desiccation correlates with elevated intracellular trehalose concentrations. Our data confirm these findings, but we have tested the apparent importance of trehalose using mutant strains with a deleted trehalose-6-phosphate synthase gene (tps1Delta). Although tps1Delta strains do not produce trehalose, they are nevertheless capable of desiccation tolerance, and the degree of tolerance also increases after diauxic shift or heat stress, albeit slightly less than in the wild type. Conversely, when wild-type yeast is subjected to osmotic stress, mid-exponential-phase cultures produce high concentrations of intracellular trehalose but show little improvement in desiccation tolerance. These results show that there is no consistent relationship between intracellular trehalose levels and desiccation tolerance in S. cerevisiae. Trehalose seems to be neither necessary nor sufficient for, although in some strains might quantitatively improve, survival of desiccation, suggesting that other adaptations are more important.

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“…Moreover, the ability of the microorganisms to survive in these environments correlates with their trehalose content [7,8]. In yeast, the most ancient actor of biotechnological transformation, trehalose was found to accumulate, in certain physiological conditions, up to 10%-15% of cell dry weight [9]. Investigation on the cell membranes of anhydrobiotic yeast has unraveled that intracellular trehalose can stabilize proteins in their native state and to reduce their heat-induced denaturation and aggregation [10,11].…”

Section: Introductionmentioning

confidence: 99%

Identification and Characterization of a Novel Trehalose Synthase Gene Derived from Saline-Alkali Soil Metagenomes

et al. 2013

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A novel trehalose synthase (TreS) gene was identified from a metagenomic library of saline-alkali soil by a simple activity-based screening system. Sequence analysis revealed that TreS encodes a protein of 552 amino acids, with a deduced molecular weight of 63.3 kDa. After being overexpressed in Escherichia coli and purified, the enzymatic properties of TreS were investigated. The recombinant TreS displayed its optimal activity at pH 9.0 and 45 °C, and the addition of most common metal ions (1 or 30 mM) had no inhibition effect on the enzymatic activity evidently, except for the divalent metal ions Zn2+ and Hg2+. Kinetic analysis showed that the recombinant TreS had a 4.1-fold higher catalytic efficientcy (Kcat/K m) for maltose than for trehalose. The maximum conversion rate of maltose into trehalose by the TreS was reached more than 78% at a relatively high maltose concentration (30%), making it a good candidate in the large-scale production of trehalsoe after further study. In addition, five amino acid residues, His172, Asp201, Glu251, His318 and Asp319, were shown to be conserved in the TreS, which were also important for glycosyl hydrolase family 13 enzyme catalysis.

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On the formation of glycogen and trehalose in baker's yeast

Cited by 47 publications

References 16 publications

Changes in the concentration of cAMP, fructose 2,6‐bisphosphate and related metabolites and enzymes in Saccharomyces cerevisiae during growth on glucose

Changes in the concentration of cAMP, fructose 2,6‐bisphosphate and related metabolites and enzymes in Saccharomyces cerevisiae during growth on glucose

Intracellular trehalose is neither necessary nor sufficient for desiccation tolerance in yeast

Identification and Characterization of a Novel Trehalose Synthase Gene Derived from Saline-Alkali Soil Metagenomes

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