Metabolite profiling for analysis of yeast stress response during very high gravity ethanol fermentations.
A laboratory strain and an industrial strain of Saccharomyces cerevisiae were grown at high substrate concentration, so-called very high gravity (VHG) fermentation. Simultaneous saccharification and fermentation (SSF) was applied in a batch process using 280 g/L maltodextrin as carbon source. It was shown that known ethanol and osmotic stress responses such as decreased growth rate, lower viability, higher energy consumption, and intracellular trehalose accumulation occur in VHG SSF for both strains when compared with standard laboratory medium (20 g/L glucose). The laboratory strain was the most affected. GC-MS metabolite profiling was applied for assessing the yeast stress response influence on cellular metabolism. It was found that metabolite profiles originating from different strains and/or fermentation conditions were unique and could be distinguished with the help of multivariate data analysis. Several differences in the metabolic responses to stressing conditions were revealed, particularly the increased energy consumption of stressed cells was also reflected in increased intracellular concentrations of pyruvate and related metabolites.
Devantier
Rasmus
R
Starch, Applied Discovery, Research & Development, Novozymes A/S, Laurentsvej 51-53, DK-2880 Bagsvaerd, Denmark.
Scheithauer
Britta
B
Villas-Bôas
Silas Granato
SG
Pedersen
Sven
S
Olsson
Lisbeth
L
D018929:Cell Culture Techniques / Q000379:methods; D000431:Ethanol / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D020869:Gene Expression Profiling / Q000379:methods*; D015966:Gene Expression Regulation, Fungal / Q000502:physiology*; D006112:Gravitation; D009997:Osmotic Pressure; D018384:Oxidative Stress / Q000502:physiology*; D020543:Proteome / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000145:classification / Q000254:growth & development / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D013045:Species Specificity
D020543:Proteome; D029701:Saccharomyces cerevisiae Proteins; D000431:Ethanol