Whole-Cell Detection by 13C NMR of Metabolic Flux through the C1-Tetrahydrofolate Synthase/Serine Hydroxymethyltransferase Enzyme System and Effect of Antifolate Exposure in Saccharomyces cerevisiae

Biochemistry ◽  
1994 ◽  
Vol 33 (23) ◽  
pp. 7166-7173 ◽  
Author(s):  
Laura B. Pasternack ◽  
David A. Laude ◽  
Dean R. Appling
Keyword(s):  
Saccharomyces Cerevisiae ◽  
13C Nmr ◽  
Metabolic Flux ◽  
Enzyme System ◽  
Serine Hydroxymethyltransferase ◽  
Cell Detection ◽  
Whole Cell ◽  
Tetrahydrofolate Synthase

Enhanced uridine 5′-monophosphate production by whole cell of Saccharomyces cerevisiae through rational redistribution of metabolic flux

2011 ◽  
Vol 35 (5) ◽  
pp. 729-737 ◽  
Author(s):  
Dong Liu ◽  
Yong Chen ◽  
An Li ◽  
Jingjing Xie ◽  
Jian Xiong ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Metabolic Flux ◽  
Whole Cell

scholarly journals Development and Characterization of Two Types of Surface Displayed Levansucrases for Levan Biosynthesis

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 757
Author(s):  
Huiyi Shang ◽  
Danni Yang ◽  
Dairong Qiao ◽  
Hui Xu ◽  
Yi Cao
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Weight ◽  
Large Scale ◽  
Surface Display ◽  
Yeast Surface Display ◽  
Fusion Partner ◽  
Whole Cell ◽  
Food Industries ◽  
Yeast Surface ◽  
The Stability

Levan has wide applications in chemical, cosmetic, pharmaceutical and food industries. The free levansucrase is usually used in the biosynthesis of levan, but the poor reusability and low stability of free levansucrase have limited its large-scale use. To address this problem, the surface-displayed levansucrase in Saccharomyces cerevisiae were generated and evaluated in this study. The levansucrase from Zymomonas mobilis was displayed on the cell surface of Saccharomyces cerevisiae EBY100 using a various yeast surface display platform. The N-terminal fusion partner is based on a-agglutinin, and the C-terminal one is Flo1p. The yield of levan produced by these two whole-cell biocatalysts reaches 26 g/L and 34 g/L in 24 h, respectively. Meanwhile, the stability of the surface-displayed levansucrases is significantly enhanced. After six reuses, these two biocatalysts retained over 50% and 60% of their initial activities, respectively. Furthermore, the molecular weight and polydispersity test of the products suggested that the whole-cell biocatalyst of levansucrase displayed by Flo1p has more potentials in the production of levan with low molecular weight which is critical in certain applications. In conclusion, our method not only enable the possibility to reuse the enzyme, but also improves the stability of the enzyme.

scholarly journals 13C NMR studies of acetate metabolism during sporulation of Saccharomyces cerevisiae.

1983 ◽  
Vol 80 (19) ◽  
pp. 5847-5851 ◽  
Author(s):  
J. R. Dickinson ◽  
I. W. Dawes ◽  
A. S. Boyd ◽  
R. L. Baxter
Keyword(s):  
Saccharomyces Cerevisiae ◽  
13C Nmr ◽  
Acetate Metabolism ◽  
Nmr Studies

scholarly journals Combined Biosynthetic Pathway Engineering and Storage Pool Expansion for High-Level Production of Ergosterol in Industrial Saccharomyces cerevisiae

2021 ◽  
Vol 9 ◽  
Author(s):  
Zhi-Jiao Sun ◽  
Jia-Zhang Lian ◽  
Li Zhu ◽  
Yi-Qi Jiang ◽  
Guo-Si Li ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Biosynthetic Pathway ◽  
Metabolic Flux ◽  
Feeding Strategy ◽  
Pathway Engineering ◽  
Ergosterol Biosynthesis ◽  
Sterol Esters ◽  
Storage Pool ◽  
Ergosterol Content ◽  
Dry Cell Weight

Ergosterol, a terpenoid compound produced by fungi, is an economically important metabolite serving as the direct precursor of steroid drugs. Herein, ergsosterol biosynthetic pathway modification combined with storage capacity enhancement was proposed to synergistically improve the production of ergosterol in Saccharomyces cerevisiae. S. cerevisiae strain S1 accumulated the highest amount of ergosterol [7.8 mg/g dry cell weight (DCW)] among the wild-type yeast strains tested and was first selected as the host for subsequent metabolic engineering studies. Then, the push and pull of ergosterol biosynthesis were engineered to increase the metabolic flux, overexpression of the sterol acyltransferase gene ARE2 increased ergosterol content to 10 mg/g DCW and additional overexpression of a global regulatory factor allele (UPC2-1) increased the ergosterol content to 16.7 mg/g DCW. Furthermore, considering the hydrophobicity sterol esters and accumulation in lipid droplets, the fatty acid biosynthetic pathway was enhanced to expand the storage pool for ergosterol. Overexpression of ACC1 coding for the acetyl-CoA carboxylase increased ergosterol content from 16.7 to 20.7 mg/g DCW. To address growth inhibition resulted from premature accumulation of ergosterol, auto-inducible promoters were employed to dynamically control the expression of ARE2, UPC2-1, and ACC1. Consequently, better cell growth led to an increase of ergosterol content to 40.6 mg/g DCW, which is 4.2-fold higher than that of the starting strain. Finally, a two-stage feeding strategy was employed for high-density cell fermentation, with an ergosterol yield of 2986.7 mg/L and content of 29.5 mg/g DCW. This study provided an effective approach for the production of ergosterol and other related terpenoid molecules.

scholarly journals Molecular Basis for Anaerobic Growth of Saccharomyces cerevisiae on Xylose, Investigated by Global Gene Expression and Metabolic Flux Analysis

2004 ◽  
Vol 70 (4) ◽  
pp. 2307-2317 ◽  
Author(s):  
Marco Sonderegger ◽  
Marie Jeppsson ◽  
Bärbel Hahn-Hägerdal ◽  
Uwe Sauer
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Metabolic Flux Analysis ◽  
Metabolic Flux ◽  
Global Gene Expression ◽  
Anaerobic Growth ◽  
Flux Analysis ◽  
Atp Production ◽  
Redox Imbalance ◽  
Chemostat Cultures

ABSTRACT Yeast xylose metabolism is generally considered to be restricted to respirative conditions because the two-step oxidoreductase reactions from xylose to xylulose impose an anaerobic redox imbalance. We have recently developed, however, a Saccharomyces cerevisiae strain that is at present the only known yeast capable of anaerobic growth on xylose alone. Using transcriptome analysis of aerobic chemostat cultures grown on xylose-glucose mixtures and xylose alone, as well as a combination of global gene expression and metabolic flux analysis of anaerobic chemostat cultures grown on xylose-glucose mixtures, we identified the distinguishing characteristics of this unique phenotype. First, the transcript levels and metabolic fluxes throughout central carbon metabolism were significantly higher than those in the parent strain, and they were most pronounced in the xylose-specific, pentose phosphate, and glycerol pathways. Second, differential expression of many genes involved in redox metabolism indicates that increased cytosolic NADPH formation and NADH consumption enable a higher flux through the two-step oxidoreductase reaction of xylose to xylulose in the mutant. Redox balancing is apparently still a problem in this strain, since anaerobic growth on xylose could be improved further by providing acetoin as an external NADH sink. This improved growth was accompanied by an increased ATP production rate and was not accompanied by higher rates of xylose uptake or cytosolic NADPH production. We concluded that anaerobic growth of the yeast on xylose is ultimately limited by the rate of ATP production and not by the redox balance per se, although the redox imbalance, in turn, limits ATP production.

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