151
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de Freitas JM, Bravim F, Buss DS, Lemos EM, Fernandes AAR, Fernandes PM. Influence of cellular fatty acid composition on the response ofSaccharomyces cerevisiaeto hydrostatic pressure stress. FEMS Yeast Res 2012; 12:871-8. [DOI: 10.1111/j.1567-1364.2012.00836.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Revised: 07/13/2012] [Accepted: 07/26/2012] [Indexed: 12/27/2022] Open
Affiliation(s)
- Jéssica M. de Freitas
- Núcleo de Biotecnologia; Centro de Ciências da Saúde; Universidade Federal do Espírito Santo; Vitória; ES; Brazil
| | - Fernanda Bravim
- Núcleo de Biotecnologia; Centro de Ciências da Saúde; Universidade Federal do Espírito Santo; Vitória; ES; Brazil
| | - David S. Buss
- Núcleo de Biotecnologia; Centro de Ciências da Saúde; Universidade Federal do Espírito Santo; Vitória; ES; Brazil
| | - Elenice M. Lemos
- Núcleo de Doenças Infecciosas; Centro de Ciências da Saúde; Universidade Federal do Espírito Santo; Vitória; ES; Brazil
| | - A. Alberto R. Fernandes
- Núcleo de Biotecnologia; Centro de Ciências da Saúde; Universidade Federal do Espírito Santo; Vitória; ES; Brazil
| | - Patricia M.B. Fernandes
- Núcleo de Biotecnologia; Centro de Ciências da Saúde; Universidade Federal do Espírito Santo; Vitória; ES; Brazil
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152
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Bailey-Shaw YA, Golden KD, Pearson AGM, Porter RBR. Characterization of Jamaican Agro-Industrial Wastes. Part II, Fatty Acid Profiling Using HPLC: Precolumn Derivatization with Phenacyl Bromide. J Chromatogr Sci 2012; 50:666-72. [DOI: 10.1093/chromsci/bms061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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153
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Cheung AWY, Brosnan JM, Phister T, Smart KA. Impact of dried, creamed and cake supply formats on the genetic variation and ethanol tolerance of three Saccharomyces cerevisiae distilling strains. JOURNAL OF THE INSTITUTE OF BREWING 2012. [DOI: 10.1002/jib.23] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Annie W. Y. Cheung
- Bioenergy and Brewing Science, School of Biosciences; University of Nottingham; Sutton Bonington Campus; Loughborough; Leics; LE12 5RD; UK
| | - James M. Brosnan
- The Scotch Whisky Research Institute; The Robertson Trust Building, Research Avenue North, Riccarton; Edinburgh; EH14 4AP; UK
| | - Trevor Phister
- Bioenergy and Brewing Science, School of Biosciences; University of Nottingham; Sutton Bonington Campus; Loughborough; Leics; LE12 5RD; UK
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154
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Yang J, Ding MZ, Li BZ, Liu ZL, Wang X, Yuan YJ. Integrated Phospholipidomics and Transcriptomics Analysis ofSaccharomyces cerevisiaewith Enhanced Tolerance to a Mixture of Acetic Acid, Furfural, and Phenol. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2012; 16:374-86. [DOI: 10.1089/omi.2011.0127] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Jie Yang
- Key Laboratory of Systems Bioengineering, Ministry of Education; Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, P.R. China
| | - Ming-Zhu Ding
- Key Laboratory of Systems Bioengineering, Ministry of Education; Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, P.R. China
| | - Bing-Zhi Li
- Key Laboratory of Systems Bioengineering, Ministry of Education; Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, P.R. China
| | - Z. Lewis Liu
- Bioenergy Research Unit, National Center for Agricultural Utilization Research, U.S. Department of Agriculture-Agricultural Research Service, Peoria, Illinois
| | - Xin Wang
- Key Laboratory of Systems Bioengineering, Ministry of Education; Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, P.R. China
| | - Ying-Jin Yuan
- Key Laboratory of Systems Bioengineering, Ministry of Education; Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, P.R. China
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155
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Gibson BR. 125th Anniversary Review: Improvement of Higher Gravity Brewery Fermentation via Wort Enrichment and Supplementation. JOURNAL OF THE INSTITUTE OF BREWING 2012. [DOI: 10.1002/j.2050-0416.2011.tb00472.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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156
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Synthesis and production of unsaturated and polyunsaturated fatty acids in yeast: current state and perspectives. Appl Microbiol Biotechnol 2012; 95:1-12. [DOI: 10.1007/s00253-012-4105-1] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Revised: 04/12/2012] [Accepted: 04/12/2012] [Indexed: 10/28/2022]
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157
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Transcriptome analysis identifies genes involved in ethanol response of Saccharomyces cerevisiae in Agave tequilana juice. Antonie Van Leeuwenhoek 2012; 102:247-55. [DOI: 10.1007/s10482-012-9733-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Accepted: 03/24/2012] [Indexed: 11/26/2022]
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158
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Li H, Ma ML, Luo S, Zhang RM, Han P, Hu W. Metabolic responses to ethanol in Saccharomyces cerevisiae using a gas chromatography tandem mass spectrometry-based metabolomics approach. Int J Biochem Cell Biol 2012; 44:1087-96. [PMID: 22504284 DOI: 10.1016/j.biocel.2012.03.017] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Revised: 03/22/2012] [Accepted: 03/26/2012] [Indexed: 11/16/2022]
Abstract
During the fermentation process, Saccharomyces cerevisiae cells are often inhibited by the accumulated ethanol, and the mechanism of the S. cerevisiae response to ethanol is not fully understood. In the current study, a systematic analytical approach was used to investigate the changes in the S. cerevisiae cell metabolome that were elicited by treatment with various concentrations of ethanol. Gas chromatography-mass spectrometry and a multivariate analysis were employed to investigate the ethanol-associated intracellular biochemical changes in S. cerevisiae. The intracellular metabolite profiles that were found upon treatment of the cells with different concentrations of ethanol were unique and could be distinguished with the aid of principal component analysis. Furthermore, partial least-squares-discriminant analysis revealed a group classification and pairwise discrimination between the control without ethanol and ethanol treated groups, and 29 differential metabolites with variable importance in the projection value greater than 1 were identified, which was also confirmed by the subsequent hierarchical cluster analysis. The metabolic relevance of these compounds in the response of S. cerevisiae to ethanol stress was investigated. Under ethanol stress, the glycolysis was inhibited and the use of carbon sources for fermentation was diminished, which might account for the growth inhibition of S. cerevisiae cells. It was suggested that S. cerevisiae cells change the levels of fatty acids, e.g., hexadecanoic, octadecanoic and palmitelaidic acids, to maintain the integrity of their plasma membrane through decreasing membrane fluidity in the medium containing ethanol. Moreover, the increased levels of some amino acids idemtified in the cells of ethanol-treated experimental group might also confer ethanol tolerance to S. cerevisiae. These results reveal that the metabolomics strategy is a powerful tool to gain insight into the molecular mechanism of a microorganism's cellular response to environmental stress factors.
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Affiliation(s)
- Hao Li
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China.
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159
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A novel strategy to construct yeast Saccharomyces cerevisiae strains for very high gravity fermentation. PLoS One 2012; 7:e31235. [PMID: 22363590 PMCID: PMC3281935 DOI: 10.1371/journal.pone.0031235] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2011] [Accepted: 01/04/2012] [Indexed: 12/01/2022] Open
Abstract
Very high gravity (VHG) fermentation is aimed to considerably increase both the fermentation rate and the ethanol concentration, thereby reducing capital costs and the risk of bacterial contamination. This process results in critical issues, such as adverse stress factors (ie., osmotic pressure and ethanol inhibition) and high concentrations of metabolic byproducts which are difficult to overcome by a single breeding method. In the present paper, a novel strategy that combines metabolic engineering and genome shuffling to circumvent these limitations and improve the bioethanol production performance of Saccharomyces cerevisiae strains under VHG conditions was developed. First, in strain Z5, which performed better than other widely used industrial strains, the gene GPD2 encoding glycerol 3-phosphate dehydrogenase was deleted, resulting in a mutant (Z5ΔGPD2) with a lower glycerol yield and poor ethanol productivity. Second, strain Z5ΔGPD2 was subjected to three rounds of genome shuffling to improve its VHG fermentation performance, and the best performing strain SZ3-1 was obtained. Results showed that strain SZ3-1 not only produced less glycerol, but also increased the ethanol yield by up to 8% compared with the parent strain Z5. Further analysis suggested that the improved ethanol yield in strain SZ3-1 was mainly contributed by the enhanced ethanol tolerance of the strain. The differences in ethanol tolerance between strains Z5 and SZ3-1 were closely associated with the cell membrane fatty acid compositions and intracellular trehalose concentrations. Finally, genome rearrangements in the optimized strain were confirmed by karyotype analysis. Hence, a combination of genome shuffling and metabolic engineering is an efficient approach for the rapid improvement of yeast strains for desirable industrial phenotypes.
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160
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Vanegas JM, Contreras MF, Faller R, Longo ML. Role of unsaturated lipid and ergosterol in ethanol tolerance of model yeast biomembranes. Biophys J 2012; 102:507-16. [PMID: 22325273 DOI: 10.1016/j.bpj.2011.12.038] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Revised: 12/21/2011] [Accepted: 12/23/2011] [Indexed: 11/27/2022] Open
Abstract
We present a combined atomic force microscopy and fluorescence microscopy study of the behavior of a ternary supported lipid bilayer system containing a saturated lipid (DPPC), an unsaturated lipid (DOPC), and ergosterol in the presence of high ethanol (20 vol %). We find that the fluorescent probe Texas Red DHPE preferentially partitions into the ethanol-induced interdigitated phase, which allows the use of fluorescence imaging to investigate the phase behavior of the system. Atomic force microscopy and fluorescence images of samples with the same lipid mixture show good agreement in sample morphology and area fractions of the observed phases. Using area fractions obtained from fluorescence images over a broad range of compositions, we constructed a phase diagram of the DPPC/DOPC/ergosterol system at 20 vol % ethanol. The phase diagram clearly shows that increasing unsaturated lipid and/or ergosterol protects the membrane by preventing the formation of the interdigitated phase. This result supports the hypothesis that yeast cells increase ergosterol and unsaturated lipid content to prevent interdigitation and maintain an optimal membrane thickness as ethanol concentration increases during anaerobic fermentations. Changes in plasma membrane composition provide an important survival factor for yeast cells to deter ethanol toxicity.
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Affiliation(s)
- Juan M Vanegas
- Biophysics Graduate Group, College of Biological Sciences, University of California, Davis, California, USA
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161
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Taylor M, Ramond JB, Tuffin M, Burton S, Eley K, Cowan D. Mechanisms and Applications of Microbial Solvent Tolerance. MICROBIOLOGY MONOGRAPHS 2012. [DOI: 10.1007/978-3-642-21467-7_8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
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162
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Henderson CM, Lozada-Contreras M, Naravane Y, Longo ML, Block DE. Analysis of major phospholipid species and ergosterol in fermenting industrial yeast strains using atmospheric pressure ionization ion-trap mass spectrometry. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2011; 59:12761-12770. [PMID: 21995817 DOI: 10.1021/jf203203h] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Knowledge of the individual lipid species that are associated with ethanol tolerance in Saccharomyces cerevisiae is necessary to understand potential mechanisms of how this organism uses these molecules to mitigate the toxic effects of ethanol. Three industrial yeast strains with varying degrees of ethanol tolerance were examined utilizing normal phase high-performance liquid chromatography and atmospheric pressure ionization-ion-trap mass spectrometry methods to quantitatively determine phospholipid and ergosterol levels at numerous fermentation time points. Both high and low Brix fermentations were performed to assess the sugar utilization capabilities of the strains. The results indicated that the strain with the most robust fermentation characteristics had the highest phosphatidylinositol levels and lowest phosphatidylcholine levels. Examination of the phospholipid structural data from tandem MS experiments indicated that the levels of several phospholipid species were unique to the slowest fermenting strain. The relation of ergosterol and other phospholipids to ethanol tolerance is also discussed.
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Affiliation(s)
- Clark M Henderson
- Biophysics Graduate Group, University of California, One Shields Avenue, Davis, California 95616, United States
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163
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Role of alcohols in growth, lipid composition, and membrane fluidity of yeasts, bacteria, and archaea. Appl Environ Microbiol 2011; 77:6400-8. [PMID: 21784917 DOI: 10.1128/aem.00694-11] [Citation(s) in RCA: 132] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Increased membrane fluidity, which causes cofactor leakage and loss of membrane potential, has long been documented as a cause for decreased cell growth during exposure to ethanol, butanol, and other alcohols. Reinforcement of the membrane with more complex lipid components is thus thought to be beneficial for the generation of more tolerant organisms. In this study, organisms with more complex membranes, namely, archaea, did not maintain high growth rates upon exposure to alcohols, indicating that more complex lipids do not necessarily fortify the membrane against the fluidizing effects of alcohols. In the presence of alcohols, shifts in lipid composition to more saturated and unbranched lipids were observed in most of the organisms tested, including archaea, yeasts, and bacteria. However, these shifts did not always result in a decrease in membrane fluidity or in greater tolerance of the organism to alcohol exposure. In general, organisms tolerating the highest concentrations of alcohols maintained membrane fluidity after alcohol exposure, whereas organisms that increased membrane rigidity were less tolerant. Altered lipid composition was a common response to alcohol exposure, with the most tolerant organisms maintaining a modestly fluid membrane. Our results demonstrate that increased membrane fluidity is not the sole cause of growth inhibition and that alcohols may also denature proteins within the membrane and cytosol, adversely affecting metabolism and decreasing cell growth.
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164
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Yazawa H, Kamisaka Y, Kimura K, Yamaoka M, Uemura H. Efficient accumulation of oleic acid in Saccharomyces cerevisiae caused by expression of rat elongase 2 gene (rELO2) and its contribution to tolerance to alcohols. Appl Microbiol Biotechnol 2011; 91:1593-600. [DOI: 10.1007/s00253-011-3410-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 05/19/2011] [Accepted: 05/22/2011] [Indexed: 11/24/2022]
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165
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Liang Q, Wang Q, Gao C, Wang Z, Qi Q. The effect of cyclodextrins on the ethanol tolerance of microorganisms suggests potential application. J Ind Microbiol Biotechnol 2011; 38:753-6. [DOI: 10.1007/s10295-011-0958-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Accepted: 03/09/2011] [Indexed: 10/18/2022]
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166
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Improvement of ethanol production using Saccharomyces cerevisiae by enhancement of biomass and nutrient supplementation. Appl Biochem Biotechnol 2011; 164:1237-45. [PMID: 21373793 DOI: 10.1007/s12010-011-9209-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Accepted: 02/22/2011] [Indexed: 10/18/2022]
Abstract
Optimization of ethanol production through addition of substratum and protein-lipid additives was studied. Oilseed meal extract was used as protein lipid supplement, while rice husk was used as substratum. The effect of oil seed meal extract and rice husk was observed at varying concentration of medium sugar from 8% to 20%. Of the three oil seed meal extracts used, viz. groundnut, safflower, and sunflower, safflower was found to be most efficient. The use of oilseed meal extract at 4% was found to enhance ethanol production by almost 50% and enhanced sugar tolerance from 8% to 16%. A further increase of almost 48% ethanol was observed on addition of 2 g of rice husk per 100 ml of medium. An increase in cell mass with better sugar attenuation was observed. Further optimization was sought through use of sugarcane juice as the sugar source. While 8.9% ethanol yield with 75% sugar attenuation was observed at 20% sucrose concentration, it was found to increase to 12% (v/v) with almost complete utilization of medium sugar when sugarcane juice was used. Cell weight was also observed to increase by 26%.
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167
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Ding MZ, Li BZ, Cheng JS, Yuan YJ. Metabolome analysis of differential responses of diploid and haploid yeast to ethanol stress. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2011; 14:553-61. [PMID: 20955008 DOI: 10.1089/omi.2010.0015] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Metabolomic analysis was carried out to investigate the metabolic differences of diploid (α/a) and homogenous haploid (α,a) yeasts, and further assess their response to ethanol stress. The dynamic metabolic variations of diploid and haploid caused by 3 and 7% (v/v) ethanol stress were evaluated by gas chromatography coupled to time-of-flight mass spectrometry combined with statistical analysis. Metabolite profiles originating from three strains in presence/absence of ethanol stress were distinctive and could be distinguished by principal components analysis. Results showed that the divergence among the strains with ethanol stress was smaller than without it. Furthermore, the levels of most glycolytic intermediates and amino acids in haploid were lower than these in diploid with/without ethanol stress, which was considered as species-specific behaviors. The increases of protective metabolites including polyols, amino acids, precursors of phospholipids, and unsaturated fatty acids under ethanol stress in three strains revealed the ethanol stress-specific responses. Higher fold change in most of these protectants in haploid indicated that haploid was more susceptible to ethanol stress than diploid. These findings provided underlying basis for better understanding diploid and haploid yeasts, and further breeding tolerant strains for efficient ethanol fermentation.
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Affiliation(s)
- Ming-Zhu Ding
- Key Laboratory of Systems Bioengineering, Ministry of Education and Department of Pharmaceutical Engineering, School of Chemical Engineering & Technology, Tianjin University, Tianjin, People's Republic of China
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168
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Park JY, Hong CS, Han JH, Kang HW, Chung BW, Choi GW, Min JH. Cellular Responses to Alcohol in Escherichia coli, Clostridium acetobutylicum, and Saccharomyces cerevisiae. KOREAN CHEMICAL ENGINEERING RESEARCH 2011. [DOI: 10.9713/kcer.2011.49.1.105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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169
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Redón M, Guillamón JM, Mas A, Rozès N. Effect of growth temperature on yeast lipid composition and alcoholic fermentation at low temperature. Eur Food Res Technol 2011. [DOI: 10.1007/s00217-010-1415-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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170
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Dupont S, Beney L, Ferreira T, Gervais P. Nature of sterols affects plasma membrane behavior and yeast survival during dehydration. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1808:1520-8. [PMID: 21081111 DOI: 10.1016/j.bbamem.2010.11.012] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Revised: 10/25/2010] [Accepted: 11/09/2010] [Indexed: 01/07/2023]
Abstract
The plasma membrane (PM) is a main site of injury during osmotic perturbation. Sterols, major lipids of the PM structure in eukaryotes, are thought to play a role in ensuring the stability of the lipid bilayer during physicochemical perturbations. Here, we investigated the relationship between the nature of PM sterols and resistance of the yeast Saccharomyces cerevisiae to hyperosmotic treatment. We compared the responses to osmotic dehydration (viability, sterol quantification, ultrastructure, cell volume, and membrane permeability) in the wild-type (WT) strain and the ergosterol mutant erg6Δ strain. Our main results suggest that the nature of membrane sterols governs the mechanical behavior of the PM during hyperosmotic perturbation. The mutant strain, which accumulates ergosterol precursors, was more sensitive to osmotic fluctuations than the WT, which accumulates ergosterol. The hypersensitivity of erg6Δ was linked to modifications of the membrane properties, such as stretching resistance and deformation, which led to PM permeabilization during the volume variation during the dehydration-rehydration cycles. Anaerobic growth of erg6Δ strain with ergosterol supplementation restored resistance to osmotic treatment. These results suggest a relationship between hydric stress resistance and the nature of PM sterols. We discuss this relationship in the context of the evolution of the ergosterol biosynthetic pathway.
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Affiliation(s)
- Sebastien Dupont
- Laboratoire de Génie des Procédés Microbiologiques et Alimentaires, Université de Bourgogne/AgroSup Dijon, 1, esplanade Erasme, 21000 Dijon, France
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171
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Kim HS, Kim NR, Choi W. Total fatty acid content of the plasma membrane of Saccharomyces cerevisiae is more responsible for ethanol tolerance than the degree of unsaturation. Biotechnol Lett 2010; 33:509-15. [DOI: 10.1007/s10529-010-0465-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Accepted: 10/27/2010] [Indexed: 10/18/2022]
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172
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Increased ethanol resistance in Ethanolic Escherichia coli by Insertion of heat-shock genes BEM1 and SOD2 from Saccharomyces cerevisiae. BIOTECHNOL BIOPROC E 2010. [DOI: 10.1007/s12257-009-3060-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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173
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Horinouchi T, Tamaoka K, Furusawa C, Ono N, Suzuki S, Hirasawa T, Yomo T, Shimizu H. Transcriptome analysis of parallel-evolved Escherichia coli strains under ethanol stress. BMC Genomics 2010; 11:579. [PMID: 20955615 PMCID: PMC3091726 DOI: 10.1186/1471-2164-11-579] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Accepted: 10/19/2010] [Indexed: 11/21/2022] Open
Abstract
Background Understanding ethanol tolerance in microorganisms is important for the improvement of bioethanol production. Hence, we performed parallel-evolution experiments using Escherichia coli cells under ethanol stress to determine the phenotypic changes necessary for ethanol tolerance. Results After cultivation of 1,000 generations under 5% ethanol stress, we obtained 6 ethanol-tolerant strains that showed an approximately 2-fold increase in their specific growth rate in comparison with their ancestor. Expression analysis using microarrays revealed that common expression changes occurred during the adaptive evolution to the ethanol stress environment. Biosynthetic pathways of amino acids, including tryptophan, histidine, and branched-chain amino acids, were commonly up-regulated in the tolerant strains, suggesting that activating these pathways is involved in the development of ethanol tolerance. In support of this hypothesis, supplementation of isoleucine, tryptophan, and histidine to the culture medium increased the specific growth rate under ethanol stress. Furthermore, genes related to iron ion metabolism were commonly up-regulated in the tolerant strains, which suggests the change in intracellular redox state during adaptive evolution. Conclusions The common phenotypic changes in the ethanol-tolerant strains we identified could provide a fundamental basis for designing ethanol-tolerant strains for industrial purposes.
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Affiliation(s)
- Takaaki Horinouchi
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka, Japan
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174
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Exploiting natural variation in Saccharomyces cerevisiae to identify genes for increased ethanol resistance. Genetics 2010; 186:1197-205. [PMID: 20855568 DOI: 10.1534/genetics.110.121871] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Ethanol production from lignocellulosic biomass holds promise as an alternative fuel. However, industrial stresses, including ethanol stress, limit microbial fermentation and thus prevent cost competitiveness with fossil fuels. To identify novel engineering targets for increased ethanol tolerance, we took advantage of natural diversity in wild Saccharomyces cerevisiae strains. We previously showed that an S288c-derived lab strain cannot acquire higher ethanol tolerance after a mild ethanol pretreatment, which is distinct from other stresses. Here, we measured acquired ethanol tolerance in a large panel of wild strains and show that most strains can acquire higher tolerance after pretreatment. We exploited this major phenotypic difference to address the mechanism of acquired ethanol tolerance, by comparing the global gene expression response to 5% ethanol in S288c and two wild strains. Hundreds of genes showed variation in ethanol-dependent gene expression across strains. Computational analysis identified several transcription factor modules and known coregulated genes as differentially expressed, implicating genetic variation in the ethanol signaling pathway. We used this information to identify genes required for acquisition of ethanol tolerance in wild strains, including new genes and processes not previously linked to ethanol tolerance, and four genes that increase ethanol tolerance when overexpressed. Our approach shows that comparative genomics across natural isolates can quickly identify genes for industrial engineering while expanding our understanding of natural diversity.
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175
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Arroyo-López FN, Salvadó Z, Tronchoni J, Guillamón JM, Barrio E, Querol A. Susceptibility and resistance to ethanol in Saccharomyces strains isolated from wild and fermentative environments. Yeast 2010; 27:1005-15. [PMID: 20824889 DOI: 10.1002/yea.1809] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Accepted: 06/21/2010] [Indexed: 11/09/2022] Open
Abstract
In this work, we apply statistical modelling techniques to study the influence of increasing concentrations of ethanol on the overall growth of 29 yeast strains belonging to different Saccharomyces and non-Saccharomyces species. A modified Gompertz equation for decay was used to objectively estimate the noninhibitory concentration (NIC) and minimum inhibitory concentration (MIC) for the assayed strains to ethanol, which are related to the susceptibility and resistance of yeasts to this compound, respectively. A first ANOVA analysis, grouping strains as a function of their respective Saccharomyces species, revealed that S. cerevisiae was the yeast with the highest, and statistically significant, ethanol resistance value. Then, a second factorial ANOVA analysis, using the origin of strains (wild or fermentative) and their taxonomic classification (S. cerevisiae, S. paradoxus or S. bayanus var. uvarum) as categorical predictor variables, showed that no significant differences for the NIC and MIC parameters were found between both ecological niches within the same species, indicative that these physiological characteristics were presumably not modified throughout the adaptation to human-manipulated fermentative environments. Finally, differences among selected strains with respect to ethanol tolerance were correlated to the initial contents of unsaturated fatty acids, mainly oleic acid.
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Affiliation(s)
- F N Arroyo-López
- Institut Cavanilles de Biodiversitat i Biologia Evolutiva. Universitat de València. Edifici d'Instituts, Parc Científic de Paterna. P.O. Box 22085, E-46071 València, Spain
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176
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Optimization of bioethanol production during simultaneous saccharification and fermentation in very high-gravity cassava mash. Antonie van Leeuwenhoek 2010; 99:329-39. [DOI: 10.1007/s10482-010-9494-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2010] [Accepted: 08/04/2010] [Indexed: 10/19/2022]
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177
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Landolfo S, Zara G, Zara S, Budroni M, Ciani M, Mannazzu I. Oleic acid and ergosterol supplementation mitigates oxidative stress in wine strains of Saccharomyces cerevisiae. Int J Food Microbiol 2010; 141:229-35. [DOI: 10.1016/j.ijfoodmicro.2010.05.020] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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178
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Ma M, Liu LZ. Quantitative transcription dynamic analysis reveals candidate genes and key regulators for ethanol tolerance in Saccharomyces cerevisiae. BMC Microbiol 2010; 10:169. [PMID: 20537179 PMCID: PMC2903563 DOI: 10.1186/1471-2180-10-169] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Accepted: 06/10/2010] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Derived from our lignocellulosic conversion inhibitor-tolerant yeast, we generated an ethanol-tolerant strain Saccharomyces cerevisiae NRRL Y-50316 by enforced evolutionary adaptation. Using a newly developed robust mRNA reference and a master equation unifying gene expression data analyses, we investigated comparative quantitative transcription dynamics of 175 genes selected from previous studies for an ethanol-tolerant yeast and its closely related parental strain. RESULTS A highly fitted master equation was established and applied for quantitative gene expression analyses using pathway-based qRT-PCR array assays. The ethanol-tolerant Y-50316 displayed significantly enriched background of mRNA abundance for at least 35 genes without ethanol challenge compared with its parental strain Y-50049. Under the ethanol challenge, the tolerant Y-50316 responded in consistent expressions over time for numerous genes belonging to groups of heat shock proteins, trehalose metabolism, glycolysis, pentose phosphate pathway, fatty acid metabolism, amino acid biosynthesis, pleiotropic drug resistance gene family and transcription factors. The parental strain showed repressed expressions for many genes and was unable to withstand the ethanol stress and establish a viable culture and fermentation. The distinct expression dynamics between the two strains and their close association with cell growth, viability and ethanol fermentation profiles distinguished the tolerance-response from the stress-response in yeast under the ethanol challenge. At least 82 genes were identified as candidate and key genes for ethanol-tolerance and subsequent fermentation under the stress. Among which, 36 genes were newly recognized by the present study. Most of the ethanol-tolerance candidate genes were found to share protein binding motifs of transcription factors Msn4p/Msn2p, Yap1p, Hsf1p and Pdr1p/Pdr3p. CONCLUSION Enriched background of transcription abundance and enhanced expressions of ethanol-tolerance genes associated with heat shock proteins, trehalose-glycolysis-pentose phosphate pathways and PDR gene family are accountable for the tolerant yeast to withstand the ethanol stress, maintain active metabolisms, and complete ethanol fermentation under the ethanol stress. Transcription factor Msn4p appeared to be a key regulator of gene interactions for ethanol-tolerance in the tolerant yeast Y-50316.
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Affiliation(s)
- Menggen Ma
- Bioenergy Research, National Center for Agricultural Utilization Research USDA-ARS, Peoria, IL USA
- Department of Computer Science, New Mexico State University, Las Cruces, NM USA
| | - Lewis Z Liu
- Bioenergy Research, National Center for Agricultural Utilization Research USDA-ARS, Peoria, IL USA
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179
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Senger RS. Biofuel production improvement with genome-scale models: The role of cell composition. Biotechnol J 2010; 5:671-85. [DOI: 10.1002/biot.201000007] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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180
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Šajbidor J, Malik F. Changes in lipid content of wine yeasts during fermentation by immobilized cells. POTRAVINARSTVO 2010. [DOI: 10.5219/56] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Comparison of the lipid composition of immobilised and non-immobilised cells of the wine cell strain Saccharomyces cerevisiae 6C subjected to ethanol stress indicates that the whole impact of the ethanol stress on the fatty acids composition is less influenced with immobilised cells as with non- immobilised ones. The ethanol stress raised in immobilised and free cells occurrence of palmitoleic acid to the detriment of palmitic acid. The character of changes in lipid composition during immobilisation probably has an impact upon slightly increased stress resistance. The immobilised cells are as well resistive against passive membrane fluidisation by ethanol.
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181
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Mechanisms of ethanol tolerance in Saccharomyces cerevisiae. Appl Microbiol Biotechnol 2010; 87:829-45. [DOI: 10.1007/s00253-010-2594-3] [Citation(s) in RCA: 170] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Revised: 03/29/2010] [Accepted: 03/29/2010] [Indexed: 12/18/2022]
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182
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Fermentation of lactose to bio-ethanol by yeasts as part of integrated solutions for the valorisation of cheese whey. Biotechnol Adv 2010; 28:375-84. [DOI: 10.1016/j.biotechadv.2010.02.002] [Citation(s) in RCA: 278] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Revised: 02/03/2010] [Accepted: 02/04/2010] [Indexed: 11/18/2022]
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183
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Selection from industrial lager yeast strains of variants with improved fermentation performance in very-high-gravity worts. Appl Environ Microbiol 2010; 76:1563-73. [PMID: 20081007 DOI: 10.1128/aem.03153-09] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
There are economic and other advantages if the fermentable sugar concentration in industrial brewery fermentations can be increased from that of currently used high-gravity (ca. 14 to 17 degrees P [degrees Plato]) worts into the very-high-gravity (VHG; 18 to 25 degrees P) range. Many industrial strains of brewer's yeast perform poorly in VHG worts, exhibiting decreased growth, slow and incomplete fermentations, and low viability of the yeast cropped for recycling into subsequent fermentations. A new and efficient method for selecting variant cells with improved performance in VHG worts is described. In this new method, mutagenized industrial yeast was put through a VHG wort fermentation and then incubated anaerobically in the resulting beer while maintaining the alpha-glucoside concentration at about 10 to 20 g.liter(-1) by slowly feeding the yeast maltose or maltotriose until most of the cells had died. When survival rates fell to 1 to 10 cells per 10(6) original cells, a high proportion (up to 30%) of survivors fermented VHG worts 10 to 30% faster and more completely (residual sugars lower by 2 to 8 g.liter(-1)) than the parent strains, but the sedimentation behavior and profiles of yeast-derived flavor compounds of the survivors were similar to those of the parent strains.
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184
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Rupčić J, Jurešić GČ. Influence of stressful fermentation conditions on neutral lipids of a Saccharomyces cerevisiae brewing strain. World J Microbiol Biotechnol 2010; 26:1331-6. [DOI: 10.1007/s11274-009-0297-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Accepted: 12/21/2009] [Indexed: 10/20/2022]
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185
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Ding J, Huang X, Zhang L, Zhao N, Yang D, Zhang K. Tolerance and stress response to ethanol in the yeast Saccharomyces cerevisiae. Appl Microbiol Biotechnol 2009; 85:253-63. [PMID: 19756577 DOI: 10.1007/s00253-009-2223-1] [Citation(s) in RCA: 194] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2009] [Revised: 08/23/2009] [Accepted: 08/24/2009] [Indexed: 11/30/2022]
Abstract
Eukaryotic cells have developed diverse strategies to combat the harmful effects of a variety of stress conditions. In the model yeast Saccharomyces cerevisiae, the increased concentration of ethanol, as the primary fermentation product, will influence the membrane fluidity and be toxic to membrane proteins, leading to cell growth inhibition and even death. Though little is known about the complex signal network responsible for alcohol stress responses in yeast cells, several mechanisms have been reported to be associated with this process, including changes in gene expression, in membrane composition, and increases in chaperone proteins that help stabilize other denatured proteins. Here, we review the recent progresses in our understanding of ethanol resistance and stress responses in yeast.
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Affiliation(s)
- Junmei Ding
- Laboratory for Conservation and Utilization of Bio-resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, Yunnan 650091, China
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186
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Improved ethanol tolerance in Escherichia coli by changing the cellular fatty acids composition through genetic manipulation. Biotechnol Lett 2009; 31:1867-71. [PMID: 19685209 DOI: 10.1007/s10529-009-0092-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2009] [Revised: 07/20/2009] [Accepted: 07/21/2009] [Indexed: 10/20/2022]
Abstract
To investigate the effect of cellular fatty acids composition on ethanol tolerance in Escherichia coli, we overexpressed either des, encoding fatty acid desaturase from Bacillus subtilis, or fabA, encoding beta-hydroxydecanoyl thio-ester dehydrase from E. coli, or both genes together, into E. coli. Recombinant E. coli harboring fabA had elevated tolerance against ethanol compared to wild type strain. In contrast, des decreased resistance to ethanol. Co-expression of both genes together complemented ethanol tolerance of E. coli. This result indicates how to engineer bacterial strains to be resistant to higher concentrations of ethanol.
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187
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Vriesekoop F, Haass C, Pamment NB. The role of acetaldehyde and glycerol in the adaptation to ethanol stress of Saccharomyces cerevisiae and other yeasts. FEMS Yeast Res 2009; 9:365-71. [PMID: 19416102 DOI: 10.1111/j.1567-1364.2009.00492.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Ethanol inhibition is a commonly encountered stress condition during typical yeast fermentations and often results in reduced fermentation rates and production yields. While past studies have shown that acetaldehyde addition has a significant ameliorating effect on the growth of ethanol-stressed Saccharomyces cerevisiae, this study investigated the potential ameliorating effect of acetaldehyde on a wide range of ethanol-stressed yeasts. Acetaldehyde does not appear to be a universal ameliorating agent for yeasts exposed to ethanol stress. It is also shown that as a result of an ethanol stress, most yeasts rapidly produce glycerol as an alternative means of NAD(+) regeneration rather than having a specific requirement for glycerol. The results strongly suggest that both ethanol and acetaldehyde exposure have a direct effect on the cellular NAD(+)/NADH ratio, which can manifest itself as modulations in glycerol production.
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Affiliation(s)
- Frank Vriesekoop
- Institute for Food and Crop Science, School of Science and Engineering, University of Ballarat, Ballarat, Victoria, Australia
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188
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Genome-wide identification of Saccharomyces cerevisiae genes required for maximal tolerance to ethanol. Appl Environ Microbiol 2009; 75:5761-72. [PMID: 19633105 DOI: 10.1128/aem.00845-09] [Citation(s) in RCA: 162] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The understanding of the molecular basis of yeast resistance to ethanol may guide the design of rational strategies to increase process performance in industrial alcoholic fermentations. In this study, the yeast disruptome was screened for mutants with differential susceptibility to stress induced by high ethanol concentrations in minimal growth medium. Over 250 determinants of resistance to ethanol were identified. The most significant gene ontology terms enriched in this data set are those associated with intracellular organization, biogenesis, and transport, in particular, regarding the vacuole, the peroxisome, the endosome, and the cytoskeleton, and those associated with the transcriptional machinery. Clustering the proteins encoded by the identified determinants of ethanol resistance by their known physical and genetic interactions highlighted the importance of the vacuolar protein sorting machinery, the vacuolar H(+)-ATPase complex, and the peroxisome protein import machinery. Evidence showing that vacuolar acidification and increased resistance to the cell wall lytic enzyme beta-glucanase occur in response to ethanol-induced stress was obtained. Based on the genome-wide results, the particular role of the FPS1 gene, encoding a plasma membrane aquaglyceroporin which mediates controlled glycerol efflux, in ethanol stress resistance was further investigated. FPS1 expression contributes to decreased [(3)H]ethanol accumulation in yeast cells, suggesting that Fps1p may also play a role in maintaining the intracellular ethanol level during active fermentation. The increased expression of FPS1 confirmed the important role of this gene in alcoholic fermentation, leading to increased final ethanol concentration under conditions that lead to high ethanol production.
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189
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Zhao XQ, Bai FW. Mechanisms of yeast stress tolerance and its manipulation for efficient fuel ethanol production. J Biotechnol 2009; 144:23-30. [PMID: 19446584 DOI: 10.1016/j.jbiotec.2009.05.001] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2009] [Revised: 04/28/2009] [Accepted: 05/06/2009] [Indexed: 11/17/2022]
Abstract
Yeast strains of Saccharomyces cerevisiae have been extensively studied in recent years for fuel ethanol production, in which yeast cells are exposed to various stresses such as high temperature, ethanol inhibition, and osmotic pressure from product and substrate sugars as well as the inhibitory substances released from the pretreatment of lignocellulosic biomass. An in-depth understanding of the mechanism of yeast stress tolerance contributes to breeding more robust strains for ethanol production, especially under very high gravity conditions. Taking advantage of the "omics" technology, the stress response and defense mechanism of yeast cells during ethanol fermentation were further explored, and the newly emerged tools such as genome shuffling and global transcription machinery engineering have been applied to breed stress resistant yeast strains for ethanol production. In this review, the latest development of stress tolerance mechanisms was focused, and improvement of yeast stress tolerance by both random and rational tools was presented.
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Affiliation(s)
- X Q Zhao
- Department of Bioscience and Bioengineering, Dalian University of Technology, China
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190
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Potential of biofilm-based biofuel production. Appl Microbiol Biotechnol 2009; 83:1-18. [PMID: 19300995 DOI: 10.1007/s00253-009-1940-9] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2008] [Revised: 03/02/2009] [Accepted: 03/02/2009] [Indexed: 01/09/2023]
Abstract
Biofilm technology has been extensively applied to wastewater treatment, but its potential application in biofuel production has not been explored. Current technologies of converting lignocellulose materials to biofuel are hampered by costly processing steps in pretreatment, saccharification, and product recovery. Biofilms may have a potential to improve efficiency of these processes. Advantages of biofilms include concentration of cell-associated hydrolytic enzymes at the biofilm-substrate interface to increase reaction rates, a layered microbial structure in which multiple species may sequentially convert complex substrates and coferment hexose and pentose as hydrolysates diffuse outward, and the possibility of fungal-bacterial symbioses that allow simultaneous delignification and saccharification. More importantly, the confined microenvironment within a biofilm selectively rewards cells with better phenotypes conferred from intercellular gene or signal exchange, a process which is absent in suspended cultures. The immobilized property of biofilm, especially when affixed to a membrane, simplifies the separation of biofuel from its producer and promotes retention of biomass for continued reaction in the fermenter. Highly consolidated bioprocessing, including delignification, saccharification, fermentation, and separation in a single reactor, may be possible through the application of biofilm technology. To date, solid-state fermentation is the only biofuel process to which the advantages of biofilms have been applied, even though it has received limited attention and improvements. The transfer of biofilm technology from environmental engineering has the potential to spur great innovations in the optimization of biofuel production.
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191
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Yeast and ethyl alcohol in viniculture. KVASNY PRUMYSL 2009. [DOI: 10.18832/kp2009006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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192
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Yoshikawa K, Tanaka T, Furusawa C, Nagahisa K, Hirasawa T, Shimizu H. Comprehensive phenotypic analysis for identification of genes affecting growth under ethanol stress inSaccharomyces cerevisiae. FEMS Yeast Res 2009; 9:32-44. [DOI: 10.1111/j.1567-1364.2008.00456.x] [Citation(s) in RCA: 181] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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193
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Matsufuji Y, Fujimura S, Ito T, Nishizawa M, Miyaji T, Nakagawa J, Ohyama T, Tomizuka N, Nakagawa T. Acetaldehyde tolerance in Saccharomyces cerevisiae involves the pentose phosphate pathway and oleic acid biosynthesis. Yeast 2009; 25:825-33. [PMID: 19061187 DOI: 10.1002/yea.1637] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
To identify genes responsible for acetaldehyde tolerance, genome-wide screening was performed using a collection of haploid Saccharomyces cerevisiae strains deleted in single genes. The screen identified 49 genes whose deletion conferred acetaldehyde sensitivity, and these were termed the genes required for acetaldehyde tolerance. We focused on six of these genes required for acetaldehyde tolerance, ZWF1, GND1, RPE1, TKL1 and TAL1, which encode enzymes in the pentose phosphate pathway (PPP), and OAR1, which encodes for NADPH-dependent 3-oxoacyl-(acyl-carrier-protein) reductase. These genes were not only responsible for acetaldehyde tolerance but also turned out to be induced by acetaldehyde. Moreover, the content of oleic acid was remarkably increased in yeast cells under acetaldehyde stress, and supplementation of oleic acid into the media partially alleviated acetaldehyde stress-induced growth inhibition of strains disrupted in the genes required for acetaldehyde tolerance and OLE1. Taken together, our data suggest that the supply of NADPH and the process of fatty acid biosynthesis are the key factors in acetaldehyde tolerance in the yeast, and that oleic acid plays an important role in acetaldehyde tolerance.
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Affiliation(s)
- Yoshimi Matsufuji
- Department of Food Science and Technology, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri, Hokkaido 099-2493, Japan
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194
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Marques F, Lasanta C, Caro I, Pérez L. Study of the lipidic and proteic composition of an industrial filmogenic yeast with applications as a nutritional supplement. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2008; 56:12025-12030. [PMID: 19090714 DOI: 10.1021/jf802040k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The lipid and protein contents of yeast strains that form "flor velum" during the aging of sherry wines have been studied during their fermentation and "velum" phases. The same analyses were carried out on two other strains that do not form velum (fermentative strains). The results show a high lipid content in velum yeast during its two phases. This strain changes its lipidic components while passing from the fermentative to the velum phase, with palmitic, palmitoleic, and stearic acid concentrations decreasing, while the oleic, behenic, and lignoceric acid concentrations increase. Furthermore, a higher proteic content can be seen during the filmogenic stage of velum yeast as compared to the fermentative stage of this strain. A well-balanced distribution of amino acids is observed, which includes all essential amino acids. The sulfurated amino acids are shown to be the most limited, and a high quantity of lysine has been detected. Finally, the values of PDCAAS (Protein Digestibility Corrected Amino Acid Score) and MEAA (Modified Index of Essential Amino Acids) of this strain make it recommendable for dietary uses.
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Affiliation(s)
- Fatima Marques
- Department of Chemical Engineering, Food Technology and Environmental Technologies, College of Sciences, Campus Rio San Pedro, University of Cadiz, PB 40, Puerto Real 11510, Spain
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195
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Taylor M, Tuffin M, Burton S, Eley K, Cowan D. Microbial responses to solvent and alcohol stress. Biotechnol J 2008; 3:1388-97. [PMID: 18956369 DOI: 10.1002/biot.200800158] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Mark Taylor
- Institute for Microbial Biotechnology and Metagenomics (IMBM), University of the Western Cape, Cape Town, South Africa
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196
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Papanikolaou S, Gortzi O, Margeli E, Chinou I, Galiotou-Panayotou M, Lalas S. Effect of Citrus essential oil addition upon growth and cellular lipids of Yarrowia lipolytica yeast. EUR J LIPID SCI TECH 2008. [DOI: 10.1002/ejlt.200800085] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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197
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Genome shuffling to improve thermotolerance, ethanol tolerance and ethanol productivity of Saccharomyces cerevisiae. J Ind Microbiol Biotechnol 2008; 36:139-47. [PMID: 18846398 DOI: 10.1007/s10295-008-0481-z] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2008] [Accepted: 09/19/2008] [Indexed: 10/21/2022]
Abstract
Genome shuffling is a powerful strategy for rapid engineering of microbial strains for desirable industrial phenotypes. Here we improved the thermotolerance and ethanol tolerance of an industrial yeast strain SM-3 by genome shuffling while simultaneously enhancing the ethanol productivity. The starting population was generated by protoplast ultraviolet irradiation and then subjected for the recursive protoplast fusion. The positive colonies from the library, created by fusing the inactivated protoplasts were screened for growth at 35, 40, 45, 50 and 55 degrees C on YPD-agar plates containing different concentrations of ethanol. Characterization of all mutants and wild-type strain in the shake-flask indicated the compatibility of three phenotypes of thermotolerance, ethanol tolerance and ethanol yields enhancement. After three rounds of genome shuffling, the best performing strain, F34, which could grow on plate cultures up to 55 degrees C, was obtained. It was found capable of completely utilizing 20% (w/v) glucose at 45-48 degrees C, producing 9.95% (w/v) ethanol, and tolerating 25% (v/v) ethanol stress.
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198
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Dinh TN, Nagahisa K, Hirasawa T, Furusawa C, Shimizu H. Adaptation of Saccharomyces cerevisiae cells to high ethanol concentration and changes in fatty acid composition of membrane and cell size. PLoS One 2008; 3:e2623. [PMID: 18612424 PMCID: PMC2440543 DOI: 10.1371/journal.pone.0002623] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2008] [Accepted: 06/02/2008] [Indexed: 11/26/2022] Open
Abstract
Background Microorganisms can adapt to perturbations of the surrounding environment to grow. To analyze the adaptation process of the yeast Saccharomyces cerevisiae to a high ethanol concentration, repetitive cultivation was performed with a stepwise increase in the ethanol concentration in the culture medium. Methodology/Principal Findings First, a laboratory strain of S. cerevisiae was cultivated in medium containing a low ethanol concentration, followed by repetitive cultivations. Then, the strain repeatedly cultivated in the low ethanol concentration was transferred to medium containing a high ethanol concentration and cultivated repeatedly in the same high-ethanol-concentration medium. When subjected to a stepwise increase in ethanol concentration with the repetitive cultivations, the yeast cells adapted to the high ethanol concentration; the specific growth rate of the adapted yeast strain did not decrease during repetitive cultivation in the medium containing the same ethanol concentration, while that of the non-adapted strain decreased during repetitive cultivation. A comparison of the fatty acid composition of the cell membrane showed that the contents in oleic acid (C18:1) in ethanol-adapted and non-adapted strains were similar, but the content of palmitic acid (C16:0) in the ethanol-adapted strains was lower than that in the non-adapted strain in media containing ethanol. Moreover, microscopic observation showed that the mother cells of the adapted yeast were significantly larger than those of the non-adapted strain. Conclusions Our results suggest that activity of cell growth defined by specific growth rate of the yeast cells adapted to stepwise increase in ethanol concentration did not decrease during repetitive cultivation in high-ethanol-concentration medium. Moreover, fatty acid content of cell membrane and the size of ethanol-adapted yeast cells were changed during adaptation process. Those might be the typical phenotypes of yeast cells adapted to high ethanol concentration. In addition, the difference in sizes of the mother cell between the non-adapted and ethanol strains suggests that the cell size, cell cycle and adaptation to ethanol are thought to be closely correlated.
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Affiliation(s)
- Thai Nho Dinh
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan
| | - Keisuke Nagahisa
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, Suita, Osaka, Japan
| | - Takashi Hirasawa
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, Suita, Osaka, Japan
| | - Chikara Furusawa
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, Suita, Osaka, Japan
| | - Hiroshi Shimizu
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, Suita, Osaka, Japan
- * E-mail:
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199
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Chen S, He Q, Greenberg ML. Loss of tafazzin in yeast leads to increased oxidative stress during respiratory growth. Mol Microbiol 2008; 68:1061-72. [PMID: 18430085 DOI: 10.1111/j.1365-2958.2008.06216.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The tafazzin (TAZ) gene is highly conserved from yeast to humans, and the yeast taz1 null mutant shows alterations in cardiolipin (CL) metabolism, mitochondrial dysfunction and stabilization of supercomplexes similar to those found in Barth syndrome, a human disorder resulting from loss of tafazzin. We have previously shown that the yeast tafazzin mutant taz1Delta, which cannot remodel CL, is ethanol-sensitive at elevated temperature. In the current report, we show that in response to ethanol, CL mutants taz1Delta as well as crd1Delta, which cannot synthesize CL, exhibited increased protein carbonylation, an indicator of reactive oxygen species (ROS). The increase in ROS is most likely not due to defective oxidant defence systems, as the CL mutants do not display sensitivity to paraquat, menadione or hydrogen peroxide (H2O2). Ethanol sensitivity and increased protein carbonylation in the taz1Delta mutant but not in crd1Delta can be rescued by supplementation with oleic acid, suggesting that oleoyl-CL and/or oleoyl-monolyso-CL enables growth of taz1Delta in ethanol by decreasing oxidative stress. Our findings of increased oxidative stress in the taz1Delta mutant during respiratory growth may have important implications for understanding the pathogenesis of Barth syndrome.
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Affiliation(s)
- Shuliang Chen
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
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200
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Santos J, Sousa MJ, Cardoso H, Inácio J, Silva S, Spencer-Martins I, Leão C. Ethanol tolerance of sugar transport, and the rectification of stuck wine fermentations. Microbiology (Reading) 2008; 154:422-430. [DOI: 10.1099/mic.0.2007/011445-0] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Júlia Santos
- Biology Center, Department of Biology, University of Minho, 4710-057 Braga, Portugal
| | - Maria João Sousa
- Biology Center, Department of Biology, University of Minho, 4710-057 Braga, Portugal
| | - Helena Cardoso
- Biology Center, Department of Biology, University of Minho, 4710-057 Braga, Portugal
| | - João Inácio
- Centro de Recursos Microbiológicos (CREM), Faculty of Sciences and Technology, New University of Lisbon, 2829-516 Caparica, Portugal
| | - Sofia Silva
- Proenol – Industria Biotecnológica Lda., 4405-194 Canelas, V. N. Gaia, Portugal
| | - Isabel Spencer-Martins
- Centro de Recursos Microbiológicos (CREM), Faculty of Sciences and Technology, New University of Lisbon, 2829-516 Caparica, Portugal
| | - Cecília Leão
- Life and Health Sciences Research Institute (IVCS), School of Health Sciences, University of Minho, 4710-057 Braga, Portugal
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