Improved Resistance against Oxidative Stress of Engineered Cellobiose-fermenting Saccharomyces cerevisiae Revealed by Metabolite Profiling

다국어 초록 (Multilingual Abstract)

Cellobiose has garnered attention as analternative carbon source for numerous biotechnologicalprocesses because it is produced when lignocellulosicbiomass is treated with endo and exo-glucanases. Anengineered Saccharomyces cerevisiae (CEL), expressingcellobiose transporter and intracellular beta-glucosidaseutilized cellobiose efficiently. As compared to the cultureusing glucose, the CEL strain grown on cellobiose produceda similar yield of ethanol with slightly reduced growth rate.
In this study, concentrations of central metabolites weremonitored at mid-log phase with GC/MS to comparecellobiose- and glucose-grown CEL strain. When the CELstrain was grown on cellobiose, intracellular trehaloseconcentration increased 6-fold as compared with the glucosegrowncells. Interestingly, the higher level of trehalose incells grown on cellobiose resulted in physiological changeswhich might be beneficial for biotechnological processes.
We observed higher resistance against oxidative stresswhen cellobiose was used. Oxidative stress is commonlyoccurred by the byproducts of pretreatment process oflignocellulosic biomass, such as 2-furaldehyde (furfural) and5-hydroxymethylfurfural (HMF). Our study demonstratedthat intracellular metabolite profiling of yeast strains can beemployed for linking intracellular concentrations of metabolitewith physiological changes of cells upon genetic andenvironmental perturbations.

참고문헌 (Reference)

1 Bengtsson, O., "Xylose reductase from Pichia stipitis with altered coenzyme preference improves ethanolic xylose fermentation by recombinant Saccharomyces cerevisiae" 2 : 9-, 2009

2 Benaroudj, N., "Trehalose accumulation during cellular stress protects cell and cellular proteins from damage by oxygen radicals" 276 : 24261-24267, 2001

3 Ha, S. J., "Single amino acid substitutions in HXT2.4 from Scheffersomyces stipitis lead to improved cellobiose fermentation by engineered Saccharomyces cerevisiae" 79 : 1500-1507, 2013

4 Kim, J. H., "Simultaneous consumption of pentose and hexose sugars: an optimal microbial phenotype for efficient fermentation of lignocellulosic biomass" 88 : 1077-1085, 2010

5 Lu, C., "Shuffling of promoters for multiple genes to optimize xylose fermentation in an engineered Saccharomyces cerevisiae strain" 73 : 6072-6077, 2007

6 Kim, S. R., "Rational and evolutionary engineering approaches uncover a small set of genetic changes efficient for rapid xylose fermentation in Saccharomyces cerevisiae" 8 : e57048-, 2013

7 Klinke, H. B., "Potential inhibitors from wet oxidation of wheat straw and their effect on ethanol production of Saccharomyces cerevisiae:Wet oxidation and fermentation by yeast" 81 : 738-747, 2003

8 Halliwell, B., "Oxygen toxicity, oxygen radicals, transition metals and disease" 219 : 1-14, 1984

9 Zheng, Y., "Overview of biomass pretreatment for cellulosic ethanol production" 2 : 51-68, 2009

10 Li, S., "Overcoming glucose repression in mixed sugar fermentation by co-expressing a cellobiose transporter and a β-glucosidase in Saccharomyces cerevisiae" 6 : 2129-2132, 2010

11 Lynd, L. R., "Microbial cellulose utilization: Fundamentals and biotechnology" 66 : 506-577, 2002

12 Ryan, D., "Metabolomics: The greatest omics of them all?" 78 : 7954-7958, 2006

13 Jeffries, T. W., "Metabolic engineering for improved fermentation of pentoses by yeasts" 63 : 495-509, 2004

14 Klinke, H. B., "Inhibition of ethanol producing yeast and bacteria by degradation products produced during pretreatment of biomass" 66 : 10-26, 2004

15 Jin, Y. S., "Improvement of xylose uptake and ethanol production in recombinant Saccharomyces cerevisiae through an inverse metabolic engineering approach" 71 : 8249-8256, 2005

16 Lange, H. C., "Improved rapid sampling for in vivo kinetics of intracellular metabolites in Saccharomyces cerevisiae" 75 : 406-415, 2001

17 Villas-Bôas, S. G., "Global metabolite analysis of yeast:Evaluation of sample preparation methods" 22 : 1155-1169, 2005

18 Allen, S. A., "Furfural induces reactive oxygen species accumulation and cellular damage in Saccharomyces cerevisiae" 3 : 2-, 2010

19 Henle, E. S., "Formation, prevention, and repair of DNA damage by iron/hydrogen peroxide" 272 : 19095-19098, 1997

20 Palmqvist, E., "Fermentation of lignocellulosic hydrolysates. II: Inhibitors and mechanisms of inhibition" 74 : 25-33, 2000

21 Mosier, N., "Features of promising technologies for pretreatment of lignocellulosic biomass" 96 : 673-686, 2005

22 Hill, J., "Environmental, economic, and energetic costs and benefits of biodiesel and ethanol biofuels" 103 : 11206-11210, 2006

23 Kahar, P., "Enhancement of xylose uptake in 2-deoxyglucose tolerant mutant of Saccharomyces cerevisiae" 111 : 557-563, 2011

24 Ha, S. J., "Engineered Saccharomyces cerevisiae capable of simultaneous cellobiose and xylose fermentation" 108 : 504-509, 2011

25 Yuan, Y., "Directed evolution of a highly efficient cellobiose utilizing pathway in an industrial Saccharomyces cerevisiae strain" 110 : 2874-2881, 2013

26 Eriksen, D. T., "Directed evolution of a cellobiose utilization pathway in Saccharomyces cerevisiae by simultaneously engineering multiple proteins" 12 : 61-, 2013

27 Bell, W., "Composition and functional analysis of the Saccharomyces cerevisiae trehalose synthase complex" 273 : 33311-33319, 1998

28 Subtil, T., "Competition between pentoses and glucose during uptake and catabolism in recombinant Saccharomyces cerevisiae" 5 : 14-, 2012

29 Karhumaa, K., "Comparison of the xylose reductase-xylitol dehydrogenase and the xylose isomerase pathways for xylose fermentation by recombinant Saccharomyces cerevisiae" 6 : 5-, 2007

30 Hamacher, T., "Characterization of the xylose-transporting properties of yeast hexose transporters and their influence on xylose utilization" 148 : 2783-2788, 2002

31 Jung, J. Y., "Characterization of GCY1 in Saccharomyces cerevisiae by metabolic profiling" 113 : 1468-1478, 2012

32 Stephanopoulos, G., "Challenges in engineering microbes for biofuels production" 315 : 801-804, 2007

33 Galazka, J. M., "Cellodextrin transport in yeast for improved biofuel production" 330 : 84-86, 2010

34 Agbor, V. B., "Biomass pretreatment: fundamentals toward application" 29 : 675-685, 2011

35 Matsushika, A., "Bioethanol production from xylose by recombinant Saccharomyces cerevisiae expressing xylose reductase, NADP+-dependent xylitol dehydrogenase, and xylulokinase" 105 : 296-299, 2008

36 Gonzalez, B., "A rapid and reliable method for metabolite extraction in yeast using boiling buffered ethanol" 13 : 1347-1355, 1997