scholarly journals MAL62 overexpression enhances uridine diphosphoglucose-dependent trehalose synthesis and glycerol metabolism for cryoprotection of baker’s yeast in lean dough

2020 ◽  
Author(s):  
Xi Sun ◽  
Jun Zhang ◽  
Hua Zhi Fan ◽  
Ping Xiao ◽  
Feng Li ◽  
...  
Keyword(s):  
Freezing Tolerance ◽  
Late Phase ◽  
Transcript Abundance ◽  
Glycerol Metabolism ◽  
Glycerol Concentration ◽  
Trehalose Synthase ◽  
Key Enzyme ◽  
Glycerol Synthesis ◽  
Alpha Glucosidase ◽  
Trehalose Synthesis

Abstract Background: In Saccharomyces cerevisiae, alpha-glucosidase (maltase) is a key enzyme in maltose metabolism. In addition, the overexpression of the alpha-glucosidase-encoding gene MAL62 has been shown to increase the freezing tolerance of yeast in lean dough. However, its cryoprotection mechanism is still not clear.Results: RNA sequencing (RNA-seq) revealed that MAL62 overexpression increased uridine diphosphoglucose (UDPG)-dependent trehalose synthesis. The changes in transcript abundance were confirmed by quantitative reverse transcription–polymerase chain reaction (qRT-PCR) and enzyme activity assays. When the UDPG-dependent trehalose synthase activity was abolished, MAL62 overexpression failed to promote the synthesis of intracellular trehalose.Moreover, in strains lacking trehalose synthesis, the cell viability in the late phase of prefermentation freezing coupled with MAL62 overexpression was slightly reduced, which can be explained by the increase in the intracellular glycerol concentration. This result was consistent with the elevated transcription of glycerol synthesis pathway members.Conclusions: The increased freezing tolerance by MAL62 overexpression is mainly achieved by the increased trehalose content via the UDPG-dependent pathway, and glycerol also plays an important role. These findings shed new light on the mechanism of yeast response to freezing in lean bread dough and can help to improve industrial yeast strains.

scholarly journals MAL62 overexpression enhances uridine diphosphoglucose-dependent trehalose synthesis and glycerol metabolism for cryoprotection of baker’s yeast in lean dough

2020 ◽  
Author(s):  
Xi Sun ◽  
Jun Zhang ◽  
Hua Zhi Fan ◽  
Ping Xiao ◽  
Feng Li ◽  
...  
Keyword(s):  
Freezing Tolerance ◽  
Late Phase ◽  
Transcript Abundance ◽  
Glycerol Metabolism ◽  
Glycerol Concentration ◽  
Trehalose Synthase ◽  
Key Enzyme ◽  
Glycerol Synthesis ◽  
Alpha Glucosidase ◽  
Trehalose Synthesis

Abstract Background: In Saccharomyces cerevisiae, the alpha-glucosidase (maltase) is a key enzyme in maltose metabolism. Overexpression of the alpha-glucosidase-encoding gene MAL62 has been shown to increase the freezing tolerance of yeast in lean dough. However, its cryoprotection mechanism is still not clear.Results: RNA sequencing (RNA-seq) revealed that MAL62 overexpression increased transcription of uridine diphosphoglucose (UDPG)-dependent trehalose synthesis. The changes in transcript abundance were confirmed by quantitative reverse transcription–polymerase chain reaction (qRT-PCR) and enzyme activity assays. When the UDPG-dependent trehalose synthase activity was abolished, MAL62 overexpression failed to promote the synthesis of intracellular trehalose. Moreover, in strains lacking trehalose synthesis, cell viability in the late phase of prefermentation freezing coupled with MAL62 overexpression was slightly reduced, which can be explained by the increase in intracellular glycerol concentration which was consistent with the elevated transcription of glycerol synthesis pathways. Conclusions: The increased freezing tolerance by MAL62 overexpression is mainly achieved by the increased trehalose content via the UDPG-dependent pathway, and glycerol plays a secondary role. These findings shed new light to the mechanism of yeast response to freezing in lean bread dough and can help the improvement of industrial yeast strains.

scholarly journals MAL62 overexpression enhances uridine diphosphoglucose-dependent trehalose synthesis and glycerol metabolism for cryoprotection of baker’s yeast in lean dough

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Xi Sun ◽  
Jun Zhang ◽  
Zhi-Hua Fan ◽  
Ping Xiao ◽  
Feng Li ◽  
...  
Keyword(s):  
Freezing Tolerance ◽  
Late Phase ◽  
Transcript Abundance ◽  
Glycerol Metabolism ◽  
Glycerol Concentration ◽  
Trehalose Synthase ◽  
Key Enzyme ◽  
Glycerol Synthesis ◽  
Alpha Glucosidase ◽  
Trehalose Synthesis

Abstract Background In Saccharomyces cerevisiae, alpha-glucosidase (maltase) is a key enzyme in maltose metabolism. In addition, the overexpression of the alpha-glucosidase-encoding gene MAL62 has been shown to increase the freezing tolerance of yeast in lean dough. However, its cryoprotection mechanism is still not clear. Results RNA sequencing (RNA-seq) revealed that MAL62 overexpression increased uridine diphosphoglucose (UDPG)-dependent trehalose synthesis. The changes in transcript abundance were confirmed by quantitative reverse transcription–polymerase chain reaction (qRT-PCR) and enzyme activity assays. When the UDPG-dependent trehalose synthase activity was abolished, MAL62 overexpression failed to promote the synthesis of intracellular trehalose. Moreover, in strains lacking trehalose synthesis, the cell viability in the late phase of prefermentation freezing coupled with MAL62 overexpression was slightly reduced, which can be explained by the increase in the intracellular glycerol concentration. This result was consistent with the elevated transcription of glycerol synthesis pathway members. Conclusions The increased freezing tolerance by MAL62 overexpression is mainly achieved by the increased trehalose content via the UDPG-dependent pathway, and glycerol also plays an important role. These findings shed new light on the mechanism of yeast response to freezing in lean bread dough and can help to improve industrial yeast strains.

Glycerol metabolism in rabbits

1968 ◽  
Vol 46 (9) ◽  
pp. 1107-1114 ◽  
Author(s):  
Jean Himms-Hagen
Keyword(s):  
Turnover Rate ◽  
Glycerol Kinase ◽  
Rabbit Liver ◽  
Constant Infusion ◽  
Glycerol Dehydrogenase ◽  
Glycerol Metabolism ◽  
Utilization Rate ◽  
Glycerol Concentration ◽  
Glycerol Utilization ◽  
Fractional Turnover

The endogenous rate of glycerol production in rabbits was measured by several techniques: constant infusion of 1,3-14C-glycerol or 2-3H-glycerol or unlabeled glycerol; single injection of 1,3-14C-glycerol or 2-3H-glycerol or unlabeled glycerol. The rate was 5.5–11.6 μmoles/kg per minute (9 rabbits). The mean fractional turnover rate was 0.0585 ± 0.0052. During infusion of noradrenaline together with 3H-glycerol, the fractional turnover rate was no different from that in the absence of noradrenaline. The maximum utilization rate of glycerol was 28.1 ± 1.40 μmoles/kg per minute. The glycerol space was 58.1% of body weight. The relationship of glycerol concentration to rate of glycerol utilization in the intact rabbit suggests the existence of an enzyme with a KM for glycerol of 0.33 × 10−3 M; the glycerol kinase of rabbit liver was found to have a KM for glycerol of 0.29 × 10−3 M. This enzyme could account for the disappearance of glycerol in the intact animal except that its Vmax is only 4% of that expected. Possible reasons for this are discussed. A glycerol dehydrogenase with a Vmax similar to that of the glycerol kinase also exists in rabbit liver; its KM for glycerol is so high (0.5 M) that it is unlikely to play a significant role in glycerol metabolism in the normal rabbit.

Expression of Candidate Cold Stress and Metabolic Related Genes in Acidithiobacillus ferrivorans PQ33 Strain Using Ferrous Iron as Electron Donor

2017 ◽  
Vol 262 ◽  
pp. 368-371
Author(s):  
Gregory Guerra-Bieberach ◽  
Robert Ccorahua-Santo ◽  
Anika Eca ◽  
Jordan Bernaldo ◽  
Tito Sánchez ◽  
...  
Keyword(s):  
Candidate Genes ◽  
Low Temperatures ◽  
Biofilm Formation ◽  
Iron Oxidation ◽  
Trehalose Synthase ◽  
Adaptation Mechanisms ◽  
Diguanylate Cyclases ◽  
Cold Adaptations ◽  
Trehalose Synthesis ◽  
Andean Mining

The identification of genes involved in cold adaptations of psychrotolerant bacteria Acidithiobacillus ferrivorans is important for biomining processes that take place at low temperatures like Andean mining installations in Peru. We have performed relative quantification RT-qPCR on candidate genes to have a role in adaptations at low temperature (5°C). The candidate genes analyzed were six: Two trehalose synthesis pathway genes, trehalose synthase (treS) and malto-oligosiltrehalose trehalohydrolase (treZ) showing no overexpression at 5°C. Two diguanylate cyclases genes related to exopolymer synthesis and biofilm formation (designated as dgc-I and dgc-II in this paper) were overexpressed at 21°C. The rusA and rusB genes involved in iron oxidation showed no significant change for rusA and no expression for rusB gene in any of both conditions. Genes rpoC, gyrB and alaS were validated as reference genes. These results show congruency with trancriptomics studies about gene expression of A. ferrivorans. Furthermore, the trehalose synthesis genes show no overexpression at low temperatures suggesting that other cold adaptation mechanisms are involved.

Biosynthesis of trehalose from maltooligosaccharides in Rhizobia

1999 ◽  
Vol 45 (8) ◽  
pp. 716-721 ◽  
Author(s):  
John G Streeter ◽  
Arvind Bhagwat
Keyword(s):  
Bradyrhizobium Japonicum ◽  
Sinorhizobium Meliloti ◽  
Liquid Culture ◽  
Symbiotic Nitrogen Fixation ◽  
Alternative Mechanism ◽  
Azorhizobium Caulinodans ◽  
Trehalose Synthase ◽  
High Concentrations ◽  
Trehalose Synthesis ◽  
Rhizobium Sp

Previously, the enzymes for trehalose synthesis that are present in Escherichia coli were demonstrated in Bradyrhizobium japonicum and B. elkanii. An alternative mechanism recently reported for the synthesis of trehalose from maltooligosaccharides was considered based on the fact that high concentrations of sugars in liquid culture stimulated the accumulation of trehalose. An assay for the synthesis of trehalose from maltooligosaccharides using crude, gel-filtered protein preparations was developed. Analysis of a variety of the Rhizobiaceae indicates that the "maltooligosaccharide mechanism" is present in B. japonicum, B. elkanii, Rhizobium sp. NGR234, Sinorhizobium meliloti, R. tropici A, R. leguminosarum bv viciae, R. l. bv trifolii, and Azorhizobium caulinodans. Synthesis of trehalose from maltooligosaccharide could not be detected in R. tropici B or R. etli. With these two exceptions, it is suggested that rhizobia have two mechanisms for the biosynthesis of trehalose.Key words: maltooligosyl trehalose synthase, maltooligosyl trehalose trehalohydrolase, symbiotic nitrogen fixation.

scholarly journals Role of Acinetobacter baylyi Crc in Catabolite Repression of Enzymes for Aromatic Compound Catabolism

2009 ◽  
Vol 191 (8) ◽  
pp. 2834-2842 ◽  
Author(s):  
Tina Zimmermann ◽  
Tobias Sorg ◽  
Simone Yasmin Siehler ◽  
Ulrike Gerischer
Keyword(s):  
Catabolite Repression ◽  
Carbon Sources ◽  
Transcript Abundance ◽  
Growth Conditions ◽  
Wild Type ◽  
Acinetobacter Baylyi ◽  
Transcript Stability ◽  
Key Enzyme ◽  
In The Wild ◽  
First Time

ABSTRACT Here, we describe for the first time the Crc (catabolite repression control) protein from the soil bacterium Acinetobacter baylyi. Expression of A. baylyi crc varied according to the growth conditions. A strain with a disrupted crc gene showed the same growth as the wild type on a number of carbon sources. Carbon catabolite repression by acetate and succinate of protocatechuate 3,4-dioxygenase, the key enzyme of protocatechuate breakdown, was strongly reduced in the crc strain, whereas in the wild-type strain it underwent strong catabolite repression. This strong effect was not based on transcriptional regulation because the transcription pattern of the pca-qui operon (encoding protocatechuate 3,4-dioxygenase) did not reflect the derepression in the absence of Crc. pca-qui transcript abundance was slightly increased in the crc strain. Lack of Crc dramatically increased the mRNA stability of the pca-qui transcript (up to 14-fold), whereas two other transcripts (pobA and catA) remained unaffected. p-Hydroxybenzoate hydroxylase activity, encoded by pobA, was not significantly different in the absence of Crc, as protocatechuate 3,4-dioxygenase was. It is proposed that A. baylyi Crc is involved in the determination of the transcript stability of the pca-qui operon and thereby effects catabolite repression.

scholarly journals Islet acid glucan-1,4-alpha-glucosidase: a putative key enzyme in nutrient-stimulated insulin secretion.

Endocrinology ◽  
1996 ◽  
Vol 137 (4) ◽  
pp. 1219-1225 ◽  
Author(s):  
I Lundquist ◽  
G Panagiotidis ◽  
A Salehi
Keyword(s):  
Insulin Secretion ◽  
Key Enzyme ◽  
Alpha Glucosidase

scholarly journals Purification and Characterization of a Trehalose Synthase from the Basidiomycete Grifola frondosa

1998 ◽  
Vol 64 (11) ◽  
pp. 4340-4345 ◽  
Author(s):  
Koki Saito ◽  
Toshiya Kase ◽  
Eiichi Takahashi ◽  
Eisaku Takahashi ◽  
Sueharu Horinouchi
Keyword(s):  
Column Chromatography ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Grifola Frondosa ◽  
Synthesis Rate ◽  
Sucrose Phosphorylase ◽  
Trehalose Synthase ◽  
Final Yield ◽  
Trehalose Synthesis

ABSTRACT A trehalose synthase (TSase) that catalyzes the synthesis of trehalose from d-glucose and α-d-glucose 1-phosphate (α-d-glucose 1-P) was detected in a basidiomycete, Grifola frondosa. TSase was purified 106-fold to homogeneity with 36% recovery by ammonium sulfate precipitation and several steps of column chromatography. The native enzyme appears to be a dimer since it has apparent molecular masses of 120 kDa, as determined by gel filtration column chromatography, and 60 kDa, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Although TSase catalyzed the phosphorolysis of trehalose to d-glucose and α-d-glucose 1-P, in addition to the synthesis of trehalose from the two substrates, the TSase equilibrium strongly favors trehalose synthesis. The optimum temperatures for phosphorolysis and synthesis of trehalose were 32.5 to 35°C and 35 to 37.5°C, respectively. The optimum pHs for these reactions were 6.5 and 6.5 to 6.8, respectively. The substrate specificity of TSase was very strict: among eight disaccharides examined, only trehalose was phosphorolyzed, and only α-d-glucose 1-P served as a donor substrate withd-glucose as the acceptor in trehalose synthesis. Two efficient enzymatic systems for the synthesis of trehalose from sucrose were identified. In system I, the α-d-glucose 1-P liberated by 1.05 U of sucrose phosphorylase was linked withd-glucose by 1.05 U of TSase, generating trehalose at the initial synthesis rate of 18 mmol/h in a final yield of 90 mol% under optimum conditions (300 mM each sucrose and glucose, 20 mM inorganic phosphate, 37.5°C, and pH 6.5). In system II, we added 1.05 U of glucose isomerase and 20 mM MgSO4 to the reaction mixture of system I to convert fructose, a by-product of the sucrose phosphorylase reaction, into glucose. This system generated trehalose at the synthesis rate of 4.5 mmol/h in the same final yield.

scholarly journals Three Enzymes for Trehalose Synthesis in Bradyrhizobium Cultured Bacteria and in Bacteroids from Soybean Nodules

2006 ◽  
Vol 72 (6) ◽  
pp. 4250-4255 ◽  
Author(s):  
J. G. Streeter ◽  
M. L. Gomez
Keyword(s):  
Bradyrhizobium Japonicum ◽  
Activity Level ◽  
Free Living ◽  
Trehalose Synthase ◽  
Validamycin A ◽  
Major Mechanism ◽  
Living State ◽  
Cultured Bacteria ◽  
Trehalose Synthesis ◽  
Periods Of Stress

ABSTRACT α,α-Trehalose is a disaccharide accumulated by many microorganisms, including rhizobia, and a common role for trehalose is protection of membrane and protein structure during periods of stress, such as desiccation. Cultured Bradyrhizobium japonicum and B. elkanii were found to have three enzymes for trehalose synthesis: trehalose synthase (TS), maltooligosyltrehalose synthase (MOTS), and trehalose-6-phosphate synthetase. The activity level of the latter enzyme was much higher than those of the other two in cultured bacteria, but the reverse was true in bacteroids from nodules. Although TS was the dominant enzyme in bacteroids, the source of maltose, the substrate for TS, is not clear; i.e., the maltose concentration in nodules was very low and no maltose was formed by bacteroid protein preparations from maltooligosaccharides. Because bacteroid protein preparations contained high trehalase activity, it was imperative to inhibit this enzyme in studies of TS and MOTS in bacteroids. Validamycin A, a commonly used trehalase inhibitor, was found to also inhibit TS and MOTS, and other trehalase inhibitors, such as trehazolin, must be used in studies of these enzymes in nodules. The results of a survey of five other species of rhizobia indicated that most species sampled had only one major mechanism for trehalose synthesis. The presence of three totally independent mechanisms for the synthesis of trehalose by Bradyrhizobium species suggests that this disaccharide is important in the function of this organism both in the free-living state and in symbiosis.

Sign in / Sign up

Export Citation Format

Share Document