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Boateng ID, Li F, Yang XM, Guo D. Combinative effect of pulsed-light irradiation and solid-state fermentation on ginkgolic acids, ginkgols, ginkgolides, bilobalide, flavonoids, product quality and sensory assessment of Ginkgo biloba dark tea. Food Chem 2024; 456:139979. [PMID: 38852441 DOI: 10.1016/j.foodchem.2024.139979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 06/01/2024] [Accepted: 06/03/2024] [Indexed: 06/11/2024]
Abstract
Pulsed light (PL) is a prospective non-thermal technology that can improve the degradation of ginkgolic acid (GA) and retain the main bioactive compounds in Ginkgo biloba leaves (GBL). However, only using PL hasn't yet achieved the ideal effect of reducing GA. Fermentation of GBL to make ginkgo dark tea (GDT) could decrease GA. Because different microbial strains are used for fermentation, their metabolites and product quality might differ. However, there is no research on the combinative effect of PL irradiation fixation and microbial strain fermentation on main bioactive compounds and sensory assessment of GDT. In this research, first, Bacillus subtilis and Saccharomyces cerevisiae were selected as fermentation strains that can reduce GA from the five microbial strains. Next, the fresh GBL was irradiated by PL for 200 s (fluences of 0.52 J/cm2), followed by B. subtilis, S. cerevisiae, or natural fermentation to make GDT. The results showed that compared with the control (unirradiated and unfermented GBL) and the only PL irradiated GBL, the GA in GDT using PL + B. subtilis fermentation was the lowest, decreasing by 29.74%; PL + natural fermentation reduced by 24.53%. The total flavonoid content increased by 14.64% in GDT using PL + B. subtilis fermentation, whose phenolic and antioxidant levels also increased significantly. Sensory evaluation showed that the color, aroma, and taste of the tea infusion of PL + B. subtilis fermentation had the highest scores. In conclusion, the combined PL irradiation and solid-state fermentation using B. subtilis can effectively reduce GA and increase the main bioactive compounds, thus providing a new technological approach for GDT with lower GA.
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Affiliation(s)
- Isaac Duah Boateng
- School of Food & Biological Engineering, Jiangsu University, Zhenjiang 212013, China.; Certified Group, 199 W Rhapsody Dr, San Antonio, Texas, TX 78216, United States of America..
| | - Fengnan Li
- School of Food & Biological Engineering, Jiangsu University, Zhenjiang 212013, China..
| | - Xiao-Ming Yang
- School of Food & Biological Engineering, Jiangsu University, Zhenjiang 212013, China..
| | - Danzhao Guo
- School of Food & Biological Engineering, Jiangsu University, Zhenjiang 212013, China..
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2
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Kyawt YY, Aung M, Xu Y, Zhou Y, Li Y, Sun Z, Zhu W, Cheng Y. Methane production and lignocellulosic degradation of wastes from rice, corn and sugarcane by natural anaerobic fungi-methanogens co-culture. World J Microbiol Biotechnol 2024; 40:109. [PMID: 38411737 DOI: 10.1007/s11274-024-03938-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Accepted: 02/22/2024] [Indexed: 02/28/2024]
Abstract
Biomass from agriculture, forestry, and urban wastes is a potential renewable organic resource for energy generation. Many investigations have demonstrated that anaerobic fungi and methanogens could be co-cultured to degrade lignocellulose for methane generation. Thus, this study aimed to evaluate the effect of natural anaerobic fungi-methanogens co-culture on the methane production and lignocellulosic degradation of wastes from rice, corn and sugarcane. Hu sheep rumen digesta was used to develop a natural anaerobic fungi-methanogen co-culture. The substrates were rice straw (RS), rich husk (RH), corn stover (CS), corn cobs (CC), and sugarcane baggage (SB). Production of total gas and methane, metabolization rate of reducing sugar, glucose, and xylose, digestibility of hemicellulose and cellulose, activity of carboxymethylcellulase and xylanase, and concentrations of total acid and acetate were highest (P < 0.05) in CC, moderate (P < 0.05) in RS and CS, and lowest (P < 0.05) in SB and RH. The pH, lactate and ethanol were lowest (P < 0.05) in CC, moderate (P < 0.05) in RS and CS, and lowest (P < 0.05) SB and RH. Formate was lowest (P < 0.05) in CC, RS and CS, moderate (P < 0.05) in SB, and lowest (P < 0.05) in RH. Therefore, this study indicated that the potential of methane production and lignocellulosic degradation by natural anaerobic fungi-methanogens co-culture were highest in CC, moderate in RS and CS, and lowest in SB and RH.
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Affiliation(s)
- Yin Yin Kyawt
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China
- Department of Animal Nutrition, University of Veterinary Science, Nay Pyi Taw, 15013, Myanmar
| | - Min Aung
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China
- Department of Animal Nutrition, University of Veterinary Science, Nay Pyi Taw, 15013, Myanmar
| | - Yao Xu
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yaqi Zhou
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yuqi Li
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zhanying Sun
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China
| | - Weiyun Zhu
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yanfen Cheng
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China.
- State Key Laboratory of Grassland Agro-Ecosystems, Center for Grassland Microbiome, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730000, China.
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Messaoudi Y, Smichi N, Allaf T, Besombes C, Allaf K, Gargouri M. Instant Controlled Pressure-Drop (DIC) for Volatile Compound Extraction and Bioethanol Production from Empty Aleppo Pinecones and Eucalyptus Chips: Process Optimization and Statistical Modeling. Appl Biochem Biotechnol 2023; 195:7086-7109. [PMID: 36988842 DOI: 10.1007/s12010-023-04437-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/15/2023] [Indexed: 03/30/2023]
Abstract
Several plant species contain volatile compounds extracted as "essential oils" through different technologies. After essential oil extraction, the residual solid is a lignocellulosic solid waste. This work proposes the instant controlled pressure-drop (DIC) technology to autovaporize volatile compounds and modify the lignocellulosic matrix. Indeed, DIC technology is a thermomechanical process based on short-time/high-temperature and pressure pretreatment. It enhances the saccharification and fermentation process (SSF) for bioethanol production. A 3-variable design of experiments optimized the DIC processing parameters to reach 100% efficiency (EE) of volatile compound extraction using response surface methodology (RSM). Eucalyptus chips presented 50 volatile identified compounds after 7 min of DIC treatment. 1,8-Cineole, β-phellandrene, aromadendrene, eudesmol, and spathulenol are the most important volatile compounds. The empty Aleppo pinecones delivered 32 volatile compounds in 5 min of DIC treatment, the most important of which were caryophyllene, nortricyclene, verbenol, and camphor. After the autovaporization extraction stage, solid fraction residues were hydrolyzed and fermented in the same stirred bioreactor, using SSF strategy for 72 h at 37 °C. The highest bioethanol yields reached 73.9% and 54.82% (g per 100 g DM) from eucalyptus chip and empty Aleppo pinecone, respectively.
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Affiliation(s)
- Yosra Messaoudi
- Biocatalysis and Industrial Enzymes Group, Laboratory of Microbial Ecology and Technology, Carthage University, National Institute of Applied Sciences and Technology, BP 676, 1080, Tunis Cedex, Tunis, Tunisia.
| | - Neila Smichi
- Biocatalysis and Industrial Enzymes Group, Laboratory of Microbial Ecology and Technology, Carthage University, National Institute of Applied Sciences and Technology, BP 676, 1080, Tunis Cedex, Tunis, Tunisia
| | | | - Colette Besombes
- Laboratory of Engineering Science and Technology for Environment (LaSIE), La Rochelle University, 17042, La Rochelle, France
| | - Karim Allaf
- Laboratory of Engineering Science and Technology for Environment (LaSIE), La Rochelle University, 17042, La Rochelle, France
| | - Mohamed Gargouri
- Biocatalysis and Industrial Enzymes Group, Laboratory of Microbial Ecology and Technology, Carthage University, National Institute of Applied Sciences and Technology, BP 676, 1080, Tunis Cedex, Tunis, Tunisia
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Valorization of Delonix regia Pods for Bioethanol Production. FERMENTATION-BASEL 2023. [DOI: 10.3390/fermentation9030289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
Delonix regia (common name: Flame tree) pods, an inexpensive lignocellulosic waste matrix, were successfully used to produce value-added bioethanol. Initially, the potentiality of D. regia pods as a lignocellulosic biomass was assessed by Fourier-transform infrared spectroscopy (FTIR), which revealed the presence of several functional groups belonging to cellulose, hemicellulose, and lignin, implying that D. regia pods could serve as an excellent lignocellulosic biomass. Response Surface Methodology (RSM) and Central Composite Design (CCD) were used to optimize pretreatment conditions of incubation time (10–70 min), H2SO4 concentration (0.5–3%), amount of substrate (0.02–0.22 g), and temperature (45–100 °C). Then, RSM-suggested 30 trials of pretreatment conditions experimented in the laboratory, and a trial using 0.16 g substrate, 3% H2SO4, 70 min incubation at 90 °C, yielded the highest amount of glucose (0.296 mg·mL−1), and xylose (0.477 mg·mL−1). Subsequently, the same trial conditions were chosen in the downstream process, and pretreated D. regia pods were subjected to enzymatic hydrolysis with 5 mL of indigenously produced cellulase enzyme (74 filter per unit [FPU]) at 50 °C for 72 h to augment the yield of fermentable sugars, yielding up to 55.57 mg·mL−1 of glucose. Finally, the released sugars were fermented to ethanol by Saccharomyces cerevisiae, yielding a maximum of 7.771% ethanol after 72 h of incubation at 30 °C. Conclusively, this study entails the successful valorization of D. regia pods for bioethanol production.
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Bordet F, Roullier-Gall C, Ballester J, Vichi S, Quintanilla-Casas B, Gougeon RD, Julien-Ortiz A, Kopplin PS, Alexandre H. Different Wines from Different Yeasts? " Saccharomyces cerevisiae Intraspecies Differentiation by Metabolomic Signature and Sensory Patterns in Wine". Microorganisms 2021; 9:microorganisms9112327. [PMID: 34835452 PMCID: PMC8620830 DOI: 10.3390/microorganisms9112327] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 10/27/2021] [Accepted: 11/01/2021] [Indexed: 11/16/2022] Open
Abstract
Alcoholic fermentation is known to be a key stage in the winemaking process that directly impacts the composition and quality of the final product. Twelve wines were obtained from fermentations of Chardonnay must made with twelve different commercial wine yeast strains of Saccharomyces cerevisiae. In our study, FT-ICR-MS, GC-MS, and sensory analysis were combined with multivariate analysis. Ultra-high-resolution mass spectrometry (uHRMS) was able to highlight hundreds of metabolites specific to each strain from the same species, although they are characterized by the same technological performances. Furthermore, the significant involvement of nitrogen metabolism in this differentiation was considered. The modulation of primary metabolism was also noted at the volatilome and sensory levels. Sensory analysis allowed us to classify wines into three groups based on descriptors associated with white wine. Thirty-five of the volatile compounds analyzed, including esters, medium-chain fatty acids, superior alcohols, and terpenes discriminate and give details about differences between wines. Therefore, phenotypic differences within the same species revealed metabolic differences that resulted in the diversity of the volatile fraction that participates in the palette of the sensory pattern. This original combination of metabolomics with the volatilome and sensory approaches provides an integrative vision of the characteristics of a given strain. Metabolomics shine the new light on intraspecific discrimination in the Saccharomyces cerevisiae species.
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Affiliation(s)
- Fanny Bordet
- Université Bourgogne Franche-Comté, AgroSup Dijon, PAM UMR A 02.102, F-21000 Dijon, France-Institut Universitaire de la Vigne et du Vin (IUVV), Rue Claude Ladrey, BP 27877, CEDEX, 21078 Dijon, France; (C.R.-G.); (R.D.G.); (H.A.)
- Lallemand SAS, 19 Rue des Briquetiers, CEDEX, 31700 Blagnac, France;
- Correspondence:
| | - Chloé Roullier-Gall
- Université Bourgogne Franche-Comté, AgroSup Dijon, PAM UMR A 02.102, F-21000 Dijon, France-Institut Universitaire de la Vigne et du Vin (IUVV), Rue Claude Ladrey, BP 27877, CEDEX, 21078 Dijon, France; (C.R.-G.); (R.D.G.); (H.A.)
| | - Jordi Ballester
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, 21000 Dijon, France;
| | - Stefania Vichi
- Food Science and Gastronomy Department, University of Barcelona, Nutrition, INSA (Institut de Recerca en Nutricio I Seguretat Alimentaria), 08921 Santa Coloma de Gramenet, Spain; (S.V.); (B.Q.-C.)
| | - Beatriz Quintanilla-Casas
- Food Science and Gastronomy Department, University of Barcelona, Nutrition, INSA (Institut de Recerca en Nutricio I Seguretat Alimentaria), 08921 Santa Coloma de Gramenet, Spain; (S.V.); (B.Q.-C.)
| | - Régis D. Gougeon
- Université Bourgogne Franche-Comté, AgroSup Dijon, PAM UMR A 02.102, F-21000 Dijon, France-Institut Universitaire de la Vigne et du Vin (IUVV), Rue Claude Ladrey, BP 27877, CEDEX, 21078 Dijon, France; (C.R.-G.); (R.D.G.); (H.A.)
- DIVVA (Développement Innovation Vigne Vin Aliments) Platform/PAM UMR, IUVV, Rue Claude Ladrey, BP 27877, CEDEX, 21078 Dijon, France
| | - Anne Julien-Ortiz
- Lallemand SAS, 19 Rue des Briquetiers, CEDEX, 31700 Blagnac, France;
| | - Philippe Schmitt Kopplin
- German Research Center for Environmental Health, Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München, D-85764 Neuherberg, Germany;
| | - Hervé Alexandre
- Université Bourgogne Franche-Comté, AgroSup Dijon, PAM UMR A 02.102, F-21000 Dijon, France-Institut Universitaire de la Vigne et du Vin (IUVV), Rue Claude Ladrey, BP 27877, CEDEX, 21078 Dijon, France; (C.R.-G.); (R.D.G.); (H.A.)
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6
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Cellulosic Bioethanol from Industrial Eucalyptus globulus Bark Residues Using Kraft Pulping as a Pretreatment. ENERGIES 2021. [DOI: 10.3390/en14082185] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The pulp and paper industry faces an emerging challenge for valorising wastes and side-streams generated according to the biorefinery concept. Eucalyptus globulus bark, an abundant industrial residue in the Portuguese pulp and paper sector, has a high potential to be converted into biobased products instead of being burned. This work aimed to evaluate the ethanol production from E. globulus bark previously submitted to kraft pulping through separate hydrolysis and fermentation (SHF) configuration. Fed-batch enzymatic hydrolysis provided a concentrated hydrolysate with 161.6 g·L−1 of cellulosic sugars. S. cerevisiae and Ethanol Red® strains demonstrated a very good fermentation performance, despite a negligible xylose consumption. S. passalidarum, a yeast known for its capability to consume pentoses, was studied in a simultaneous co-culture with Ethanol Red®. However, bioethanol production was not improved. The best fermentation performance was achieved by Ethanol Red®, which provided a maximum ethanol concentration near 50 g·L−1 and fermentation efficiency of 80%. Concluding, kraft pulp from E. globulus bark showed a high potential to be converted into cellulosic bioethanol, being susceptible to implementing an integrated biorefinery on the pulp and paper industrial plants.
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7
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Wawro A. Improvement of Acetic Acid Tolerance in Saccharomyces cerevisiae by Novel Genome Shuffling. APPL BIOCHEM MICRO+ 2021. [DOI: 10.1134/s0003683821020198] [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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8
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Gutmann F, Jann C, Pereira F, Johansson A, Steinmetz LM, Patil KR. CRISPRi screens reveal genes modulating yeast growth in lignocellulose hydrolysate. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:41. [PMID: 33568224 PMCID: PMC7874482 DOI: 10.1186/s13068-021-01880-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 01/07/2021] [Indexed: 05/13/2023]
Abstract
BACKGROUND Baker's yeast is a widely used eukaryotic cell factory, producing a diverse range of compounds including biofuels and fine chemicals. The use of lignocellulose as feedstock offers the opportunity to run these processes in an environmentally sustainable way. However, the required hydrolysis pretreatment of lignocellulosic material releases toxic compounds that hamper yeast growth and consequently productivity. RESULTS Here, we employ CRISPR interference in S. cerevisiae to identify genes modulating fermentative growth in plant hydrolysate and in presence of lignocellulosic toxins. We find that at least one-third of hydrolysate-associated gene functions are explained by effects of known toxic compounds, such as the decreased growth of YAP1 or HAA1, or increased growth of DOT6 knock-down strains in hydrolysate. CONCLUSION Our study confirms previously known genetic elements and uncovers new targets towards designing more robust yeast strains for the utilization of lignocellulose hydrolysate as sustainable feedstock, and, more broadly, paves the way for applying CRISPRi screens to improve industrial fermentation processes.
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Affiliation(s)
- Friederike Gutmann
- European Molecular Biology Laboratory (EMBL), Structural and Cell Biology Unit, 69117, Heidelberg, Germany
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125, Berlin, Germany
| | - Cosimo Jann
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, 69117, Heidelberg, Germany.
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland.
| | - Filipa Pereira
- European Molecular Biology Laboratory (EMBL), Structural and Cell Biology Unit, 69117, Heidelberg, Germany.
| | - Andreas Johansson
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, 69117, Heidelberg, Germany
| | - Lars M Steinmetz
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, 69117, Heidelberg, Germany
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, 94305, USA
- Stanford Genome Technology Center, Palo Alto, CA, 94304, USA
| | - Kiran R Patil
- European Molecular Biology Laboratory (EMBL), Structural and Cell Biology Unit, 69117, Heidelberg, Germany.
- MRC Toxicology Unit, University of Cambridge, Cambridge, UK.
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9
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Lopes AMM, Félix de Mélo AH, Procópio DP, Teixeira GS, Carazzolle MF, de Carvalho LM, Adelantado N, Pereira GA, Ferrer P, Filho FM, Goldbeck R. Genome sequence of Acremonium strictum AAJ6 strain isolated from the Cerrado biome in Brazil and CAZymes expression in thermotolerant industrial yeast for ethanol production. Process Biochem 2020. [DOI: 10.1016/j.procbio.2020.07.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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10
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Cunha JT, Soares PO, Baptista SL, Costa CE, Domingues L. Engineered Saccharomyces cerevisiae for lignocellulosic valorization: a review and perspectives on bioethanol production. Bioengineered 2020; 11:883-903. [PMID: 32799606 PMCID: PMC8291843 DOI: 10.1080/21655979.2020.1801178] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The biorefinery concept, consisting in using renewable biomass with economical and energy goals, appeared in response to the ongoing exhaustion of fossil reserves. Bioethanol is the most prominent biofuel and has been considered one of the top chemicals to be obtained from biomass. Saccharomyces cerevisiae, the preferred microorganism for ethanol production, has been the target of extensive genetic modifications to improve the production of this alcohol from renewable biomasses. Additionally, S. cerevisiae strains from harsh industrial environments have been exploited due to their robust traits and improved fermentative capacity. Nevertheless, there is still not an optimized strain capable of turning second generation bioprocesses economically viable. Considering this, and aiming to facilitate and guide the future development of effective S. cerevisiae strains, this work reviews genetic engineering strategies envisioning improvements in 2nd generation bioethanol production, with special focus in process-related traits, xylose consumption, and consolidated bioprocessing. Altogether, the genetic toolbox described proves S. cerevisiae to be a key microorganism for the establishment of a bioeconomy, not only for the production of lignocellulosic bioethanol, but also having potential as a cell factory platform for overall valorization of renewable biomasses.
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Affiliation(s)
- Joana T Cunha
- CEB - Centre of Biological Engineering, University of Minho, Campus Gualtar , Braga, Portugal
| | - Pedro O Soares
- CEB - Centre of Biological Engineering, University of Minho, Campus Gualtar , Braga, Portugal
| | - Sara L Baptista
- CEB - Centre of Biological Engineering, University of Minho, Campus Gualtar , Braga, Portugal
| | - Carlos E Costa
- CEB - Centre of Biological Engineering, University of Minho, Campus Gualtar , Braga, Portugal
| | - Lucília Domingues
- CEB - Centre of Biological Engineering, University of Minho, Campus Gualtar , Braga, Portugal
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11
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Evaluation of the Fermentative Capacity of Saccharomyces cerevisiae CAT-1 and BB9 Strains and Pichia kudriavzevii BB2 at Simulated Industrial Conditions. Indian J Microbiol 2020; 60:494-504. [PMID: 33087999 DOI: 10.1007/s12088-020-00891-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 05/29/2020] [Indexed: 01/12/2023] Open
Abstract
The search for promising yeasts that surpass the fermentative capacity of commercial strains, such as Saccharomyces cerevisiae CAT-1, is of great importance for industrial ethanol processes in the world. Two yeasts, Pichia kudriavzevii BB2 and Saccharomyces cerevisiae BB9, were evaluated in comparison to the industrial yeast S. cerevisiae CAT-1. The objective was to evaluate the performance profile of the three studied strains in terms of growth, substrate consumption, and metabolite formation, aiming to determine their behaviour in different media and pH conditions. The results showed that under cultivation conditions simulating the medium used in the industrial process (must at 22° Brix at pH 3.0) the highest ethanol productivity was 0.41 g L-1 h-1 for S. cerevisiae CAT-1, compared to 0.11 g L-1 h-1 and 0.16 g L-1 h-1 for P. kudriavzevii and S. cerevisiae BB2, respectively. S. cerevisiae CAT-1 produced three times more ethanol in must at pH 3.0 (28.30 g L-1) and in mineral medium at pH 3.0 (29.17 g L-1) and 5.0 (30.70 g L-1) when compared to the value obtained in sugarcane must pH 3.0 (9.89 g L-1). It was concluded that S. cerevisiae CAT-1 was not limited by the variation in pH in the mineral medium due to its nutritional composition, guaranteeing better performance of the yeast even in the presence of stressors. Only S. cerevisiae CAT-1 expressed he constitutive invertase enzyme, which is responsible for hydrolysing the sucrose contained in the must.
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12
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Li Y, Hou Z, Shi Q, Cheng Y, Zhu W. Methane Production From Different Parts of Corn Stover via a Simple Co-culture of an Anaerobic Fungus and Methanogen. Front Bioeng Biotechnol 2020; 8:314. [PMID: 32426337 PMCID: PMC7204275 DOI: 10.3389/fbioe.2020.00314] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Accepted: 03/23/2020] [Indexed: 12/27/2022] Open
Abstract
To determine ways to improve the utilization of corn stover, this study investigated methane production from different parts of corn stover using a simple co-culture of an anaerobic fungus (Pecoramyces species) and methanogen (Methanobrevibacter species). The simple co-culture was incubated with the stem pith, leaf blade, or stem bark of corn stover (as substrates) at 39°C for 72 h. The results showed that the stem bark had the lowest (P < 0.05) digestibility (38.0 ± 1.36%) and neutral detergent solubles, that is, cell solubles (31.6 ± 0.45%), and the highest (P < 0.05) lignin content (4.8 ± 0.56%). The leaf blade had a significantly higher methane conversion rate (56.6 ± 0.76 mL/g digested substrate) than the stem pith (49.2 ± 1.60 mL/g digested substrate), even though they showed similar levels of methane production (42.4 ± 1.0 mL and 40.9 ± 1.35 mL, respectively). Both the leaf blade and stem pith of corn stover have the potential to produce methane in a simple co-culture of an anaerobic fungus and methanogen.
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Affiliation(s)
- Yuqi Li
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China.,Joint International Research Laboratory of Animal Health and Food Safety, Nanjing Agriculture University, Nanjing, China
| | - Zhesheng Hou
- College of Mechanical and Electrical Engineering, Jilin Institute of Chemical Technology, Jilin, China
| | - Qicheng Shi
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China.,Joint International Research Laboratory of Animal Health and Food Safety, Nanjing Agriculture University, Nanjing, China
| | - Yanfen Cheng
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China.,Joint International Research Laboratory of Animal Health and Food Safety, Nanjing Agriculture University, Nanjing, China
| | - Weiyun Zhu
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China.,Joint International Research Laboratory of Animal Health and Food Safety, Nanjing Agriculture University, Nanjing, China
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13
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de Melo AHF, Lopes AMM, Dezotti N, Santos IL, Teixeira GS, Goldbeck R. Evolutionary Engineering of Two Robust Brazilian Industrial Yeast Strains for Thermotolerance and Second-Generation Biofuels. Ind Biotechnol (New Rochelle N Y) 2020. [DOI: 10.1089/ind.2019.0031] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Affiliation(s)
- Allan Henrique Felix de Melo
- Bioprocess and Metabolic Engineering Laboratory, School of Food Engineering, University of Campinas, Campinas, SP, Brazil
| | - Alberto Moura Mendes Lopes
- Bioprocess and Metabolic Engineering Laboratory, School of Food Engineering, University of Campinas, Campinas, SP, Brazil
| | - Nicole Dezotti
- Bioprocess and Metabolic Engineering Laboratory, School of Food Engineering, University of Campinas, Campinas, SP, Brazil
| | - Isabella Laporte Santos
- Bioprocess and Metabolic Engineering Laboratory, School of Food Engineering, University of Campinas, Campinas, SP, Brazil
| | - Gleidson Silva Teixeira
- Bioprocess and Metabolic Engineering Laboratory, School of Food Engineering, University of Campinas, Campinas, SP, Brazil
| | - Rosana Goldbeck
- Bioprocess and Metabolic Engineering Laboratory, School of Food Engineering, University of Campinas, Campinas, SP, Brazil
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Roach MJ, Borneman AR. New genome assemblies reveal patterns of domestication and adaptation across Brettanomyces (Dekkera) species. BMC Genomics 2020; 21:194. [PMID: 32122298 PMCID: PMC7052964 DOI: 10.1186/s12864-020-6595-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Accepted: 02/19/2020] [Indexed: 01/05/2023] Open
Abstract
Background Yeasts of the genus Brettanomyces are of significant interest, both for their capacity to spoil, as well as their potential to positively contribute to different industrial fermentations. However, considerable variance exists in the depth of research and knowledgebase of the five currently known species of Brettanomyces. For instance, Brettanomyces bruxellensis has been heavily studied and many resources are available for this species, whereas Brettanomyces nanus is rarely studied and lacks a publicly available genome assembly altogether. The purpose of this study is to fill this knowledge gap and explore the genomic adaptations that have shaped the evolution of this genus. Results Strains for each of the five widely accepted species of Brettanomyces (Brettanomyces anomalus, B. bruxellensis, Brettanomyces custersianus, Brettanomyces naardenensis, and B. nanus) were sequenced using a combination of long- and short-read sequencing technologies. Highly contiguous assemblies were produced for each species. Structural differences between the species’ genomes were observed with gene expansions in fermentation-relevant genes (particularly in B. bruxellensis and B. nanus) identified. Numerous horizontal gene transfer (HGT) events in all Brettanomyces species’, including an HGT event that is probably responsible for allowing B. bruxellensis and B. anomalus to utilize sucrose were also observed. Conclusions Genomic adaptations and some evidence of domestication that have taken place in Brettanomyces are outlined. These new genome assemblies form a valuable resource for future research in Brettanomyces.
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Affiliation(s)
- Michael J Roach
- The Australian Wine Research Institute, PO Box 197, Glen Osmond, South Australia, 5046, Australia
| | - Anthony R Borneman
- The Australian Wine Research Institute, PO Box 197, Glen Osmond, South Australia, 5046, Australia.
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Ethanol Production from Hydrolyzed Kraft Pulp by Mono- and Co-Cultures of Yeasts: The Challenge of C6 and C5 Sugars Consumption. ENERGIES 2020. [DOI: 10.3390/en13030744] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Second-generation bioethanol production’s main bottleneck is the need for a costly and technically difficult pretreatment due to the recalcitrance of lignocellulosic biomass (LCB). Chemical pulping can be considered as a LCB pretreatment since it removes lignin and targets hemicelluloses to some extent. Chemical pulps could be used to produce ethanol. The present study aimed to investigate the batch ethanol production from unbleached Kraft pulp of Eucalyptus globulus by separate hydrolysis and fermentation (SHF). Enzymatic hydrolysis of the pulp resulted in a glucose yield of 96.1 ± 3.6% and a xylose yield of 94.0 ± 7.1%. In an Erlenmeyer flask, fermentation of the hydrolysate using Saccharomyces cerevisiae showed better results than Scheffersomyces stipitis. At both the Erlenmeyer flask and bioreactor scale, co-cultures of S. cerevisiae and S. stipitis did not show significant improvements in the fermentation performance. The best result was provided by S. cerevisiae alone in a bioreactor, which fermented the Kraft pulp hydrolysate with an ethanol yield of 0.433 g·g−1 and a volumetric ethanol productivity of 0.733 g·L−1·h−1, and a maximum ethanol concentration of 19.24 g·L−1 was attained. Bioethanol production using the SHF of unbleached Kraft pulp of E. globulus provides a high yield and productivity.
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16
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Dakal TC, Dhabhai B. Current status of genetic & metabolic engineering and novel QTL mapping-based strategic approach in bioethanol production. GENE REPORTS 2019. [DOI: 10.1016/j.genrep.2019.100497] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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17
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Shi Q, Li Y, Li Y, Cheng Y, Zhu W. Effects of steam explosion on lignocellulosic degradation of, and methane production from, corn stover by a co-cultured anaerobic fungus and methanogen. BIORESOURCE TECHNOLOGY 2019; 290:121796. [PMID: 31319215 DOI: 10.1016/j.biortech.2019.121796] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 07/09/2019] [Accepted: 07/10/2019] [Indexed: 05/23/2023]
Abstract
The aim of this study was to investigate the effects of steam explosion on lignocellulose digestibility of, and methane production from corn stover by a co-culture of anaerobic fungus and methanogen. The cumulative methane production at 72 h of incubation from the steam-exploded corn stover was 32.2 ± 1.74 mL, which not significantly different (P > 0.05) from that of the untreated corn stover (37.1 ± 1.09 mL). However, steam explosion decreased the hemicellulose contents of corn stover by 28.0 ± 0.39% and increased the neutral detergent solute by 23.5 ± 0.25%. While this treatment did not affect the dry matter digestibility (64.1 ± 0.26%, and 64.1 ± 0.28%, respectively). In conclusion, the co-culture of anaerobic fungus and methanogen can degrade the crude fibrous portion of corn stover without any pretreatments. It possesses promising biotechnological prospects for conversion of crop residue based straw resources to obtain biofuel in the form of methane.
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Affiliation(s)
- Qicheng Shi
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China
| | - Yuqi Li
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China
| | - Yuanfei Li
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China
| | - Yanfen Cheng
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China.
| | - Weiyun Zhu
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China
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Choudhary J, Singh S, Tiwari R, Goel R, Nain L. An iTRAQ Based Comparative Proteomic Profiling of Thermotolerant Saccharomyces cerevisiae JRC6 in Response to High Temperature Fermentation. CURR PROTEOMICS 2019. [DOI: 10.2174/1570164616666190131145217] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Background:
Bioethanol derived from lignocellulosic biomass can supplement the ethanol
supplies in a sustainable manner. However, the bioethanol production process is still not cost effective
and researchers are looking for novel strategies like simultaneous saccharification fermentation to cut
down the production cost. Thermotolerant yeast Saccharomyces cerevisiae JRC6 is reported to improve
the fermentation efficiency under SSF. However, the mechanism of thermotolerance of the
strain is unknown which is important for developing more robust yeast strains for simultaneous saccharification
and fermentation.
Objective:
To identify proteomic changes responsible for imparting thermotolerance by iTRAQ based
profiling of Saccharomyces cerevisiae JRC6 by growing at optimum (30°C) and high temperature (40°C).
Methods: iTRAQ labeling followed by electrospray ionization based tandem mass spectrometry using
SCIEX 5600 Triple-TOF Mass Spectrometer (MS).
Methods:
iTRAQ labeling followed by electrospray ionization based tandem mass spectrometry using
SCIEX 5600 Triple-TOF Mass Spectrometer (MS).
Results:
A total of 582 proteins involved in heat shock, metabolism, biosynthesis, transport of biomolecules,
cell division, etc. were identified. Cells grown at 40°C showed many-fold increase in the
expression for many proteins involved in different functions specially biosynthesis, heat stress and metabolism.
At 40°C heat shock proteins (78), prefoldin subunit (6), DNA binding protein SNT1, J type
co-chaperone JAC1, elongation factor 1-β, glutathione synthase, malate synthase (2), purine biosynthesis
protein ADE17, SSD1 protein, alcohol dehydrogenase 1, 3, 60S ribosomal protein L35-B, mitochondrial
import protein MAS5 and many other proteins were significantly upregulated.
Conclusion:
The iTRAQ analysis revealed many heat shock proteins and heat stable alcohol dehydrogenases
which can be exploited to develop a more robust yeast strain suitable for simultaneous saccharification
and fermentation or consolidated bioprocessing.
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Affiliation(s)
- Jairam Choudhary
- Division of Microbiology, ICAR-Indian Agricultural Research Institute, New Delhi-110012, India
| | - Surender Singh
- Division of Microbiology, ICAR-Indian Agricultural Research Institute, New Delhi-110012, India
| | - Rameshwar Tiwari
- Division of Microbiology, ICAR-Indian Agricultural Research Institute, New Delhi-110012, India
| | - Renu Goel
- Drug Discovery Research Centre (DDRC), Translational Health Science and Technology Institute (THSTI), Faridabad - 121001, India
| | - Lata Nain
- Division of Microbiology, ICAR-Indian Agricultural Research Institute, New Delhi-110012, India
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Wang Z, Qi Q, Lin Y, Guo Y, Liu Y, Wang Q. QTL analysis reveals genomic variants linked to high-temperature fermentation performance in the industrial yeast. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:59. [PMID: 30923567 PMCID: PMC6423876 DOI: 10.1186/s13068-019-1398-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 03/08/2019] [Indexed: 05/26/2023]
Abstract
BACKGROUND High-temperature fermentation is desirable for the industrial production of ethanol, which requires thermotolerant yeast strains. However, yeast thermotolerance is a complicated quantitative trait. The understanding of genetic basis behind high-temperature fermentation performance is still limited. Quantitative trait locus (QTL) mapping by pooled-segregant whole genome sequencing has been proved to be a powerful and reliable approach to identify the loci, genes and single nucleotide polymorphism (SNP) variants linked to quantitative traits of yeast. RESULTS One superior thermotolerant industrial strain and one inferior thermosensitive natural strain with distinct high-temperature fermentation performances were screened from 124 Saccharomyces cerevisiae strains as parent strains for crossing and segregant isolation. Based on QTL mapping by pooled-segregant whole genome sequencing as well as the subsequent reciprocal hemizygosity analysis (RHA) and allele replacement analysis, we identified and validated total eight causative genes in four QTLs that linked to high-temperature fermentation of yeast. Interestingly, loss of heterozygosity in five of the eight causative genes including RXT2, ECM24, CSC1, IRA2 and AVO1 exhibited positive effects on high-temperature fermentation. Principal component analysis (PCA) of high-temperature fermentation data from all the RHA and allele replacement strains of those eight genes distinguished three superior parent alleles including VPS34, VID24 and DAP1 to be greatly beneficial to high-temperature fermentation in contrast to their inferior parent alleles. Strikingly, physiological impacts of the superior parent alleles of VPS34, VID24 and DAP1 converged on cell membrane by increasing trehalose accumulation or reducing membrane fluidity. CONCLUSIONS This work revealed eight novel causative genes and SNP variants closely associated with high-temperature fermentation performance. Among these genes, VPS34 and DAP1 would be good targets for improving high-temperature fermentation of the industrial yeast. It also showed that loss of heterozygosity of causative genes could contribute to the improvement of high-temperature fermentation capacities. Our findings would provide guides to develop more robust and thermotolerant strains for the industrial production of ethanol.
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Affiliation(s)
- Zhen Wang
- CAS Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Qi Qi
- CAS Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Yuping Lin
- CAS Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Yufeng Guo
- CAS Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Yanfang Liu
- CAS Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Qinhong Wang
- CAS Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
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Selection of thermotolerant Saccharomyces cerevisiae for high temperature ethanol production from molasses and increasing ethanol production by strain improvement. Antonie van Leeuwenhoek 2019; 112:975-990. [PMID: 30666530 DOI: 10.1007/s10482-019-01230-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 01/12/2019] [Indexed: 10/27/2022]
Abstract
A thermotolerant ethanol fermenting yeast strain is a key requirement for effective ethanol production at high temperature. This work aimed to select a thermotolerant yeast producing a high ethanol concentration from molasses and increasing its ethanol production by mutagenesis. Saccharomyces cerevisiae DMKU 3-S087 was selected from 168 ethanol producing strains because it produced the highest ethanol concentration from molasses at 40 °C. Optimization of molasses broth composition was performed by the response surface method using Box-Behnken design. In molasses broth containing optimal total fermentable sugars (TFS) of 200 g/L and optimal (NH4)2SO4 of 1 g/L, with an initial pH of 5.5 by shaking flask cultivation at 40 °C ethanol, productivity and yield were 58.4 ± 0.24 g/L, 1.39 g/L/h and 0.29 g/g, respectively. Batch fermentation in a 5 L stirred-tank fermenter with 3 L optimized molasses broth adjusted to an initial pH of 5.5 and fermentation controlled at 40 °C and 300 rpm agitation resulted in 72.4 g/L ethanol, 1.21 g/L/h productivity and 0.36 g/g yield at 60 h. Strain DMKU 3-S087 improvement was performed by mutagenesis using ultraviolet radiation and ethyl methane sulfonate (EMS). Six EMS mutants produced higher ethanol (65.2 ± 0.48-73.0 ± 0.54 g/L) in molasses broth containing 200 g/L TFS and 1 g/L (NH4)2SO4 by shake flask fermentation at 37 °C than the wild type (59.8 ± 0.25 g/L). Among these mutants, only mutant S087E100-265 produced higher ethanol (62.5 ± 0.26 g/L) than the wild type (59.5 ± 0.02 g/L) at 40 °C. In addition, mutant S087E100-265 showed better tolerance to high sugar concentration, furfural, hydroxymethylfurfural and acetic acid than the wild type.
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21
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Recent Advancements in Mycodegradation of Lignocellulosic Biomass for Bioethanol Production. Fungal Biol 2019. [DOI: 10.1007/978-3-030-23834-6_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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22
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Second Generation Bioethanol Production: On the Use of Pulp and Paper Industry Wastes as Feedstock. FERMENTATION-BASEL 2018. [DOI: 10.3390/fermentation5010004] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Due to the health and environment impacts of fossil fuels utilization, biofuels have been investigated as a potential alternative renewable source of energy. Bioethanol is currently the most produced biofuel, mainly of first generation, resulting in food-fuel competition. Second generation bioethanol is produced from lignocellulosic biomass, but a costly and difficult pretreatment is required. The pulp and paper industry has the biggest income of biomass for non-food-chain production, and, simultaneously generates a high amount of residues. According to the circular economy model, these residues, rich in monosaccharides, or even in polysaccharides besides lignin, can be utilized as a proper feedstock for second generation bioethanol production. Biorefineries can be integrated in the existing pulp and paper industrial plants by exploiting the high level of technology and also the infrastructures and logistics that are required to fractionate and handle woody biomass. This would contribute to the diversification of products and the increase of profitability of pulp and paper industry with additional environmental benefits. This work reviews the literature supporting the feasibility of producing ethanol from Kraft pulp, spent sulfite liquor, and pulp and paper sludge, presenting and discussing the practical attempt of biorefineries implementation in pulp and paper mills for bioethanol production.
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23
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High temperature alcoholic fermentation by new thermotolerant yeast strains Pichia kudriavzevii isolated from sugarcane field soil. ACTA ACUST UNITED AC 2018. [DOI: 10.1016/j.anres.2018.11.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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24
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Chamnipa N, Thanonkeo S, Klanrit P, Thanonkeo P. The potential of the newly isolated thermotolerant yeast Pichia kudriavzevii RZ8-1 for high-temperature ethanol production. Braz J Microbiol 2018; 49:378-391. [PMID: 29154013 PMCID: PMC5914142 DOI: 10.1016/j.bjm.2017.09.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Revised: 07/29/2017] [Accepted: 09/06/2017] [Indexed: 11/30/2022] Open
Abstract
High potential, thermotolerant, ethanol-producing yeasts were successfully isolated in this study. Based on molecular identification and phylogenetic analysis, the isolated thermotolerant yeasts were clustered in the genera of Pichia kudriavzevii, Candida tropicalis, Candida orthopsilosis, Candida glabrata and Kodamea ohmeri. A comparative study of ethanol production using 160g/L glucose as a substrate revealed several yeast strains that could produce high ethanol concentrations at high temperatures. When sugarcane bagasse (SCB) hydrolysate containing 85g/L glucose was used as a substrate, the yeast strain designated P. kudriavzevii RZ8-1 exhibited the highest ethanol concentrations of 35.51g/L and 33.84g/L at 37°C and 40°C, respectively. It also exhibited multi-stress tolerance, such as heat, ethanol and acetic acid tolerance. During ethanol fermentation at high temperature (42°C), genes encoding heat shock proteins (ssq1 and hsp90), alcohol dehydrogenases (adh1, adh2, adh3 and adh4) and glyceraldehyde-3-phosphate dehydrogenase (tdh2) were up-regulated, suggesting that these genes might play a crucial role in the thermotolerance ability of P. kudriavzevii RZ8-1 under heat stress. These findings suggest that the growth and ethanol fermentation activities of this organism under heat stress were restricted to the expression of genes involved not only in heat shock response but also in the ethanol production pathway.
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Affiliation(s)
- Nuttaporn Chamnipa
- Khon Kaen University, Graduate School, Khon Kaen, Thailand; Khon Kaen University, Faculty of Technology, Department of Biotechnology, Khon Kaen, Thailand
| | - Sudarat Thanonkeo
- Mahasarakam University, Walai Rukhavej Botanical Research Institute, Maha Sarakam, Thailand
| | - Preekamol Klanrit
- Khon Kaen University, Faculty of Technology, Department of Biotechnology, Khon Kaen, Thailand; Khon Kaen University, Fermentation Research Center for Value Added Agricultural Products, Khon Kaen, Thailand
| | - Pornthap Thanonkeo
- Khon Kaen University, Faculty of Technology, Department of Biotechnology, Khon Kaen, Thailand; Khon Kaen University, Fermentation Research Center for Value Added Agricultural Products, Khon Kaen, Thailand.
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MATSUMOTO IZUMI, ARAI TAKAHIRO, NISHIMOTO YUI, LEELAVATCHARAMAS VICHAI, FURUTA MASAKAZU, KISHIDA MASAO. Thermotolerant Yeast Kluyveromyces marxianus Reveals More Tolerance to Heat Shock than the Brewery Yeast Saccharomyces cerevisiae. Biocontrol Sci 2018; 23:133-138. [DOI: 10.4265/bio.23.133] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- IZUMI MATSUMOTO
- Division of Applied Life Science, Graduate School of Applied and Environmental Sciences, Osaka Prefecture University
| | - TAKAHIRO ARAI
- Division of Quantum and Radiation Engineering, Graduate School of Engineering, Osaka Prefecture University
| | - YUI NISHIMOTO
- Division of Applied Life Science, Graduate School of Applied and Environmental Sciences, Osaka Prefecture University
| | - VICHAI LEELAVATCHARAMAS
- Division of Applied Life Science, Graduate School of Applied and Environmental Sciences, Osaka Prefecture University
- Department of Biotechnology, Faculty of Technology, Khon Kaen University
| | - MASAKAZU FURUTA
- Division of Quantum and Radiation Engineering, Graduate School of Engineering, Osaka Prefecture University
| | - MASAO KISHIDA
- Division of Applied Life Science, Graduate School of Applied and Environmental Sciences, Osaka Prefecture University
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Althuri A, Chintagunta AD, Sherpa KC, Banerjee R. Simultaneous Saccharification and Fermentation of Lignocellulosic Biomass. BIOFUEL AND BIOREFINERY TECHNOLOGIES 2018. [DOI: 10.1007/978-3-319-67678-4_12] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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27
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Li Y, Jin W, Mu C, Cheng Y, Zhu W. Indigenously associated methanogens intensified the metabolism in hydrogenosomes of anaerobic fungi with xylose as substrate. J Basic Microbiol 2017; 57:933-940. [PMID: 28791723 DOI: 10.1002/jobm.201700132] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 05/22/2017] [Accepted: 06/25/2017] [Indexed: 01/14/2023]
Abstract
Anaerobic fungi are potent lignocellulose degraders, but have not yet been exploited in this capacity, largely owing to their poor metabolic characterization. In the current study, a time course of fermentation was conducted to study the effect of the co-cultured methanogens on xylose metabolism by anaerobic fungi. The fermentation end-products from anaerobic fungal monoculture were H2 (6.7 ml), CO2 (65.7 ml), formate (17.90 mM), acetate (9.00 mM), lactate (11.89 mM), ethanol, and malate after 96 h fermentation. Compared to the monoculture, the end-products of co-culture shifted to more CO2 (71.8 ml) and acetate (15.20 mM), methane (14.9 ml), less lactate (5.28 mM), and hardly detectable formate and H2 at the end of fermentation. After 48 h, accumulated formate was remarkably consumed by co-cultured methanogens, accompanied by significantly increased acetate, CO2 and pH, and decreased lactate and malate. Xylose utilization, in both cultures, was similar during fermentation. However, the relative flux of carbon in hydrogenosomes in the co-culture was higher than that in the monoculture. In conclusion, the co-culture with methanogens enhanced "energy yields" of anaerobic fungi by removing the accumulated formate, decreased the metabolism in cytosol, for example, the lactate pathway, and increased the metabolism in hydrogenosomes, for example, the acetate pathway.
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Affiliation(s)
- Yuanfei Li
- Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Laboratory of Gastrointestinal Microbiology, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Wei Jin
- Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Laboratory of Gastrointestinal Microbiology, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Chunlong Mu
- Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Laboratory of Gastrointestinal Microbiology, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Yanfen Cheng
- Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Laboratory of Gastrointestinal Microbiology, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Weiyun Zhu
- Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Laboratory of Gastrointestinal Microbiology, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu, China
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Xylan-hydrolyzing thermotolerant Candida tropicalis HNMA-1 for bioethanol production from sugarcane bagasse hydrolysate. ANN MICROBIOL 2017. [DOI: 10.1007/s13213-017-1292-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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29
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Aranda-Martinez A, Naranjo Ortiz MÁ, Abihssira García IS, Zavala-Gonzalez EA, Lopez-Llorca LV. Ethanol production from chitosan by the nematophagous fungus Pochonia chlamydosporia and the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana. Microbiol Res 2017; 204:30-39. [PMID: 28870289 DOI: 10.1016/j.micres.2017.07.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 06/14/2017] [Accepted: 07/21/2017] [Indexed: 01/08/2023]
Abstract
Chitin is the second most abundant biopolymer after cellulose and virtually unexplored as raw material for bioethanol production. In this paper, we investigate chitosan, the deacetylated form of chitin which is the main component of shellfish waste, as substrate for bioethanol production by fungi. Fungal parasites of invertebrates such as the nematophagous Pochonia chlamydosporia (Pc) or the entomopathogens Beauveria bassiana (Bb) and Metarhizium anisopliae (Ma) are biocontrol agents of plant parasitic nematodes (eg. Meloidogyne spp.) or insect pests such as the red palm weevil (Rhynchophorus ferrugineus). These fungi degrade chitin-rich barriers for host penetration. We have therefore tested the chitin/chitosanolytic capabilities of Pc, Bb and Ma for generating reducing sugars using chitosan as only nutrient. Among the microorganisms used in this study, Pc is the best chitosan degrader, even under anaerobic conditions. These fungi have alcohol dehydrogenase (ADH) and pyruvate decarboxylase (PDC) encoding genes in their genomes. We have therefore analyzed their ethanol production under anaerobic conditions using chitosan as raw material. P. chlamydosporia is the largest ethanol producer from chitosan. Our studies are a starting point to develop chitin-chitosan based biofuels.
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Affiliation(s)
- Almudena Aranda-Martinez
- Laboratory of Plant Pathology, Department of Marine Sciences and Applied Biology, Multidisciplinary Institute for Environmental Studies Ramón Margalef, University of Alicante, Alicante, Spain.
| | | | - Isabel Sofía Abihssira García
- Laboratory of Plant Pathology, Department of Marine Sciences and Applied Biology, Multidisciplinary Institute for Environmental Studies Ramón Margalef, University of Alicante, Alicante, Spain.
| | - Ernesto A Zavala-Gonzalez
- Laboratory of Plant Pathology, Department of Marine Sciences and Applied Biology, Multidisciplinary Institute for Environmental Studies Ramón Margalef, University of Alicante, Alicante, Spain.
| | - Luis Vicente Lopez-Llorca
- Laboratory of Plant Pathology, Department of Marine Sciences and Applied Biology, Multidisciplinary Institute for Environmental Studies Ramón Margalef, University of Alicante, Alicante, Spain.
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Guan N, Li J, Shin HD, Du G, Chen J, Liu L. Microbial response to environmental stresses: from fundamental mechanisms to practical applications. Appl Microbiol Biotechnol 2017; 101:3991-4008. [PMID: 28409384 DOI: 10.1007/s00253-017-8264-y] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 03/23/2017] [Accepted: 03/27/2017] [Indexed: 10/19/2022]
Abstract
Environmental stresses are usually active during the process of microbial fermentation and have significant influence on microbial physiology. Microorganisms have developed a series of strategies to resist environmental stresses. For instance, they maintain the integrity and fluidity of cell membranes by modulating their structure and composition, and the permeability and activities of transporters are adjusted to control nutrient transport and ion exchange. Certain transcription factors are activated to enhance gene expression, and specific signal transduction pathways are induced to adapt to environmental changes. Besides, microbial cells also have well-established repair mechanisms that protect their macromolecules against damages inflicted by environmental stresses. Oxidative, hyperosmotic, thermal, acid, and organic solvent stresses are significant in microbial fermentation. In this review, we summarize the modus operandi by which these stresses act on cellular components, as well as the corresponding resistance mechanisms developed by microorganisms. Then, we discuss the applications of these stress resistance mechanisms on the production of industrially important chemicals. Finally, we prospect the application of systems biology and synthetic biology in the identification of resistant mechanisms and improvement of metabolic robustness of microorganisms in environmental stresses.
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Affiliation(s)
- Ningzi Guan
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China.,School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Jianghua Li
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Hyun-Dong Shin
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Guocheng Du
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Jian Chen
- Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Long Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China. .,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China.
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Techaparin A, Thanonkeo P, Klanrit P. High-temperature ethanol production using thermotolerant yeast newly isolated from Greater Mekong Subregion. Braz J Microbiol 2017; 48:461-475. [PMID: 28365094 PMCID: PMC5498443 DOI: 10.1016/j.bjm.2017.01.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 01/04/2017] [Accepted: 01/05/2017] [Indexed: 11/24/2022] Open
Abstract
The application of high-potential thermotolerant yeasts is a key factor for successful ethanol production at high temperatures. Two hundred and thirty-four yeast isolates from Greater Mekong Subregion (GMS) countries, i.e., Thailand, The Lao People's Democratic Republic (Lao PDR) and Vietnam were obtained. Five thermotolerant yeasts, designated Saccharomyces cerevisiae KKU-VN8, KKU-VN20, and KKU-VN27, Pichia kudriavzevii KKU-TH33 and P. kudriavzevii KKU-TH43, demonstrated high temperature and ethanol tolerance levels up to 45 °C and 13% (v/v), respectively. All five strains produced higher ethanol concentrations and exhibited greater productivities and yields than the industrial strain S. cerevisiae TISTR5606 during high-temperature fermentation at 40 °C and 43 °C. S. cerevisiae KKU-VN8 demonstrated the best performance for ethanol production from glucose at 37 °C with an ethanol concentration of 72.69 g/L, a productivity of 1.59 g/L/h and a theoretical ethanol yield of 86.27%. The optimal conditions for ethanol production of S. cerevisiae KKU-VN8 from sweet sorghum juice (SSJ) at 40 °C were achieved using the Box–Behnken experimental design (BBD). The maximal ethanol concentration obtained during fermentation was 89.32 g/L, with a productivity of 2.48 g/L/h and a theoretical ethanol yield of 96.32%. Thus, the newly isolated thermotolerant S. cerevisiae KKU-VN8 exhibits a great potential for commercial-scale ethanol production in the future.
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Affiliation(s)
- Atiya Techaparin
- Graduate School, Khon Kaen University, Khon Kaen 40002, Thailand; Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Pornthap Thanonkeo
- Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002, Thailand; Fermentation Research Center for Value Added Agricultural Products (FerVAAP), Khon Kaen University, Khon Kaen 40002, Thailand
| | - Preekamol Klanrit
- Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002, Thailand; Fermentation Research Center for Value Added Agricultural Products (FerVAAP), Khon Kaen University, Khon Kaen 40002, Thailand.
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32
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Moreno AD, Alvira P, Ibarra D, Tomás-Pejó E. Production of Ethanol from Lignocellulosic Biomass. PRODUCTION OF PLATFORM CHEMICALS FROM SUSTAINABLE RESOURCES 2017. [DOI: 10.1007/978-981-10-4172-3_12] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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33
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Matsushika A, Negi K, Suzuki T, Goshima T, Hoshino T. Identification and Characterization of a Novel Issatchenkia orientalis GPI-Anchored Protein, IoGas1, Required for Resistance to Low pH and Salt Stress. PLoS One 2016; 11:e0161888. [PMID: 27589271 PMCID: PMC5010203 DOI: 10.1371/journal.pone.0161888] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Accepted: 08/12/2016] [Indexed: 01/01/2023] Open
Abstract
The use of yeasts tolerant to acid (low pH) and salt stress is of industrial importance for several bioproduction processes. To identify new candidate genes having potential roles in low-pH tolerance, we screened an expression genomic DNA library of a multiple-stress-tolerant yeast, Issatchenkia orientalis (Pichia kudriavzevii), for clones that allowed Saccharomyces cerevisiae cells to grow under highly acidic conditions (pH 2.0). A genomic DNA clone containing two putative open reading frames was obtained, of which the putative protein-coding gene comprising 1629 bp was retransformed into the host. This transformant grew significantly at pH 2.0, and at pH 2.5 in the presence of 7.5% Na2SO4. The predicted amino acid sequence of this new gene, named I. orientalis GAS1 (IoGAS1), was 60% identical to the S. cerevisiae Gas1 protein, a glycosylphosphatidylinositol-anchored protein essential for maintaining cell wall integrity, and 58-59% identical to Candida albicans Phr1 and Phr2, pH-responsive proteins implicated in cell wall assembly and virulence. Northern hybridization analyses indicated that, as for the C. albicans homologs, IoGAS1 expression was pH-dependent, with expression increasing with decreasing pH (from 4.0 to 2.0) of the medium. These results suggest that IoGAS1 represents a novel pH-regulated system required for the adaptation of I. orientalis to environments of diverse pH. Heterologous expression of IoGAS1 complemented the growth and morphological defects of a S. cerevisiae gas1Δ mutant, demonstrating that IoGAS1 and the corresponding S. cerevisiae gene play similar roles in cell wall biosynthesis. Site-directed mutagenesis experiments revealed that two conserved glutamate residues (E161 and E262) in the IoGas1 protein play a crucial role in yeast morphogenesis and tolerance to low pH and salt stress. Furthermore, overexpression of IoGAS1 in S. cerevisiae remarkably improved the ethanol fermentation ability at pH 2.5, and at pH 2.0 in the presence of salt (5% Na2SO4), compared to that of a reference strain. Our results strongly suggest that constitutive expression of the IoGAS1 gene in S. cerevisiae could be advantageous for several fermentation processes under these stress conditions.
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Affiliation(s)
- Akinori Matsushika
- Research Institute for Sustainable Chemistry (ISC), National Institute of Advanced Industrial Science and Technology (AIST), Hiroshima, Japan
- Graduate School of Advanced Sciences of Matter, Hiroshima University, Hiroshima, Japan
- * E-mail:
| | - Kanako Negi
- Research Institute for Sustainable Chemistry (ISC), National Institute of Advanced Industrial Science and Technology (AIST), Hiroshima, Japan
| | - Toshihiro Suzuki
- Research Institute for Sustainable Chemistry (ISC), National Institute of Advanced Industrial Science and Technology (AIST), Hiroshima, Japan
| | - Tetsuya Goshima
- National Research Institute of Brewing (NRIB), Hiroshima, Japan
| | - Tamotsu Hoshino
- Research Institute for Sustainable Chemistry (ISC), National Institute of Advanced Industrial Science and Technology (AIST), Hiroshima, Japan
- Graduate School of Advanced Sciences of Matter, Hiroshima University, Hiroshima, Japan
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Li Y, Jin W, Cheng Y, Zhu W. Effect of the Associated Methanogen Methanobrevibacter thaueri on the Dynamic Profile of End and Intermediate Metabolites of Anaerobic Fungus Piromyces sp. F1. Curr Microbiol 2016; 73:434-441. [PMID: 27287262 DOI: 10.1007/s00284-016-1078-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 05/29/2016] [Indexed: 01/31/2023]
Abstract
Although the scheme of metabolic pathways involved in the production of the major end products has been described, the dynamic profile of metabolites of anaerobic fungi co-cultured with methanogens is limited, especially for the intermediate metabolites. In the present study, the fermentation of the co-culture of Piromyces sp. F1 and Methanobrevibacter thaueri on glucose was investigated. The presence of methanogens shortened the growth lag time of anaerobic fungi and enhanced the total gas production. The occurrence of the maximum cell dry weight and the disappearance of most of the substrate were observed at 24 h for the co-culture and 48 h for the fungal mono-culture. In the co-culture, hydrogen was detected at a very low level during fermentation, and formate transitorily accumulated at 24 h and disappeared at 48 h, resulting in an increase of pH. Acetate was higher during the fermentation in the co-culture (P < 0.05), while lactate and ethanol were higher only in the initial stage of fermentation (P < 0.05). After 48 h, lactate in the mono-culture became much higher than that in the co-culture (P < 0.05), and ethanol tended to remain the same in both cultures. Moreover, malate tended to be exhausted in the co-culture, while it accumulated in the mono-culture. Citrate was also detected in both co-culture and mono-culture. Collectively, these results suggest that methanogen enhanced the malate pathway and weakened the lactate pathway of anaerobic fungus.
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Affiliation(s)
- Yuanfei Li
- Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Laboratory of Gastrointestinal Microbiology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Wei Jin
- Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Laboratory of Gastrointestinal Microbiology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yanfen Cheng
- Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Laboratory of Gastrointestinal Microbiology, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Weiyun Zhu
- Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Laboratory of Gastrointestinal Microbiology, Nanjing Agricultural University, Nanjing, 210095, China
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35
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Choudhary J, Singh S, Nain L. Thermotolerant fermenting yeasts for simultaneous saccharification fermentation of lignocellulosic biomass. ELECTRON J BIOTECHN 2016. [DOI: 10.1016/j.ejbt.2016.02.007] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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36
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Dubey R, Jakeer S, Gaur NA. Screening of natural yeast isolates under the effects of stresses associated with second-generation biofuel production. J Biosci Bioeng 2016; 121:509-16. [DOI: 10.1016/j.jbiosc.2015.09.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 09/04/2015] [Accepted: 09/08/2015] [Indexed: 11/16/2022]
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37
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Ethanol Production from Sweet Sorghum Juice at High Temperatures Using a Newly Isolated Thermotolerant Yeast Saccharomyces cerevisiae DBKKU Y-53. ENERGIES 2016. [DOI: 10.3390/en9040253] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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38
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Satomura A, Miura N, Kuroda K, Ueda M. Reconstruction of thermotolerant yeast by one-point mutation identified through whole-genome analyses of adaptively-evolved strains. Sci Rep 2016; 6:23157. [PMID: 26984760 DOI: 10.1038/srep23157] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 03/01/2016] [Indexed: 01/26/2023] Open
Abstract
Saccharomyces cerevisiae is used as a host strain in bioproduction, because of its rapid growth, ease of genetic manipulation, and high reducing capacity. However, the heat produced during the fermentation processes inhibits the biological activities and growth of the yeast cells. We performed whole-genome sequencing of 19 intermediate strains previously obtained during adaptation experiments under heat stress; 49 mutations were found in the adaptation steps. Phylogenetic tree revealed at least five events in which these strains had acquired mutations in the CDC25 gene. Reconstructed CDC25 point mutants based on a parental strain had acquired thermotolerance without any growth defects. These mutations led to the downregulation of the cAMP-dependent protein kinase (PKA) signaling pathway, which controls a variety of processes such as cell-cycle progression and stress tolerance. The one-point mutations in CDC25 were involved in the global transcriptional regulation through the cAMP/PKA pathway. Additionally, the mutations enabled efficient ethanol fermentation at 39 °C, suggesting that the one-point mutations in CDC25 may contribute to bioproduction.
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Affiliation(s)
- Atsushi Satomura
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, Japan.,Japan Society for the Promotion of Science, Sakyo-ku, Kyoto, Japan
| | - Natsuko Miura
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, Japan
| | - Kouichi Kuroda
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, Japan
| | - Mitsuyoshi Ueda
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, Japan
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39
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Caspeta L, Castillo T, Nielsen J. Modifying Yeast Tolerance to Inhibitory Conditions of Ethanol Production Processes. Front Bioeng Biotechnol 2015; 3:184. [PMID: 26618154 PMCID: PMC4641163 DOI: 10.3389/fbioe.2015.00184] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Accepted: 10/28/2015] [Indexed: 11/17/2022] Open
Abstract
Saccharomyces cerevisiae strains having a broad range of substrate utilization, rapid substrate consumption, and conversion to ethanol, as well as good tolerance to inhibitory conditions are ideal for cost-competitive ethanol production from lignocellulose. A major drawback to directly design S. cerevisiae tolerance to inhibitory conditions of lignocellulosic ethanol production processes is the lack of knowledge about basic aspects of its cellular signaling network in response to stress. Here, we highlight the inhibitory conditions found in ethanol production processes, the targeted cellular functions, the key contributions of integrated -omics analysis to reveal cellular stress responses according to these inhibitors, and current status on design-based engineering of tolerant and efficient S. cerevisiae strains for ethanol production from lignocellulose.
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Affiliation(s)
- Luis Caspeta
- Centro de Investigación en Biotecnología, Universidad Autónoma del Estado de Morelos , Cuernavaca , Mexico
| | - Tania Castillo
- Centro de Investigación en Biotecnología, Universidad Autónoma del Estado de Morelos , Cuernavaca , Mexico
| | - Jens Nielsen
- Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology , Gothenburg , Sweden ; Department of Biology and Biological Engineering, Chalmers University of Technology , Gothenburg , Sweden ; Novo Nordisk Foundation Center for Biosustainability , Hørsholm , Denmark
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40
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Thermotolerant Yeast Strains Adapted by Laboratory Evolution Show Trade-Off at Ancestral Temperatures and Preadaptation to Other Stresses. mBio 2015. [PMID: 26199325 PMCID: PMC4513085 DOI: 10.1128/mbio.00431-15] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
A major challenge for the production of ethanol from biomass-derived feedstocks is to develop yeasts that can sustain growth under the variety of inhibitory conditions present in the production process, e.g., high osmolality, high ethanol titers, and/or elevated temperatures (≥40°C). Using adaptive laboratory evolution, we previously isolated seven Saccharomyces cerevisiae strains with improved growth at 40°C. Here, we show that genetic adaptations to high temperature caused a growth trade-off at ancestral temperatures, reduced cellular functions, and improved tolerance of other stresses. Thermotolerant yeast strains showed horizontal displacement of their thermal reaction norms to higher temperatures. Hence, their optimal and maximum growth temperatures increased by about 3°C, whereas they showed a growth trade-off at temperatures below 34°C. Computational analysis of the physical properties of proteins showed that the lethal temperature for yeast is around 49°C, as a large fraction of the yeast proteins denature above this temperature. Our analysis also indicated that the number of functions involved in controlling the growth rate decreased in the thermotolerant strains compared with the number in the ancestral strain. The latter is an advantageous attribute for acquiring thermotolerance and correlates with the reduction of yeast functions associated with loss of respiration capacity. This trait caused glycerol overproduction that was associated with the growth trade-off at ancestral temperatures. In combination with altered sterol composition of cellular membranes, glycerol overproduction was also associated with yeast osmotolerance and improved tolerance of high concentrations of glucose and ethanol. Our study shows that thermal adaptation of yeast is suitable for improving yeast resistance to inhibitory conditions found in industrial ethanol production processes. Yeast thermotolerance can significantly reduce the production costs of biomass conversion to ethanol. However, little information is available about the underlying genetic changes and physiological functions required for yeast thermotolerance. We recently revealed the genetic changes of thermotolerance in thermotolerant yeast strains (TTSs) generated through adaptive laboratory evolution. Here, we examined these TTSs’ physiology and computed their proteome stability over the entire thermal niche, as well as their preadaptation to other stresses. Using this approach, we showed that TTSs exhibited evolutionary trade-offs in the ancestral thermal niche, as well as reduced numbers of growth functions and preadaptation to other stresses found in ethanol production processes. This information will be useful for rational engineering of yeast thermotolerance for the production of biofuels and chemicals.
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Park WK, Yang JW, Kim HS. Identification of novel genes responsible for salt tolerance by transposon mutagenesis in Saccharomyces cerevisiae. ACTA ACUST UNITED AC 2015; 42:567-75. [DOI: 10.1007/s10295-015-1584-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 01/09/2015] [Indexed: 10/24/2022]
Abstract
Abstract
Saccharomyces cerevisiae strains tolerant to salt stress are important for the production of single-cell protein using kimchi waste brine. In this study, two strains (TN-1 and TN-2) tolerant of up to 10 % (w/v) NaCl were isolated by screening a transposon-mediated mutant library. The determination of transposon insertion sites and Northern blot analysis identified two genes, MDJ1 and VPS74, and revealed disruptions of the open reading frame of both genes, indicating that salt tolerance can be conferred. Such tolerant phenotypes reverted to sensitive phenotypes on the autologous or overexpression of each gene. The two transposon mutants grew faster than the control strain when cultured at 30 °C in rich medium containing 5, 7.5 or 10 % NaCl. The genes identified in this study may provide a basis for application in developing industrial yeast strains.
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Affiliation(s)
- Won-Kun Park
- grid.37172.30 0000000122920500 Department of Chemical and Biomolecular Engineering KAIST 291, Daehak-ro, Yuseong-gu 350-701 Daejeon Korea
| | - Ji-Won Yang
- grid.37172.30 0000000122920500 Department of Chemical and Biomolecular Engineering KAIST 291, Daehak-ro, Yuseong-gu 350-701 Daejeon Korea
| | - Hyun-Soo Kim
- grid.440940.d 0000000404463336 Department of Food Science and Industry Jungwon University 85, Munmu-ro, Goesan-eup, Goesan-gun 367-805 Chungbuk Korea
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42
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Nugroho RH, Yoshikawa K, Shimizu H. Metabolomic analysis of acid stress response in Saccharomyces cerevisiae. J Biosci Bioeng 2015; 120:396-404. [PMID: 25795572 DOI: 10.1016/j.jbiosc.2015.02.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 02/17/2015] [Accepted: 02/19/2015] [Indexed: 12/24/2022]
Abstract
Acid stress has been reported to inhibit cell growth and decrease productivity during bio-production processes. In this study, a metabolomics approach was conducted to understand the effect of lactic acid induced stress on metabolite pools in Saccharomyces cerevisiae. Cells were cultured with lactic acid as the acidulant, with or without initial pH control, i.e., at pH 6 or pH 2.5, respectively. Under conditions of low pH, lactic acid led to a decrease in the intracellular pH and specific growth rate; however, these parameters remained unaltered in the cultures with pH control. Capillary electrophoresis-mass spectrometry followed by a statistical principal component analysis was used to identify the metabolites and measure the increased concentrations of ATP, glutathione and proline during severe acid stress. Addition of proline to the acidified cultures improved the specific growth rates. We hypothesized that addition of proline protected the cells from acid stress by combating acid-induced oxidative stress. Lactic acid diffusion into the cell resulted in intracellular acidification, which elicited an oxidative stress response and resulted in increased glutathione levels.
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Affiliation(s)
- Riyanto Heru Nugroho
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Katsunori Yoshikawa
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Hiroshi Shimizu
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan.
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Castillo RDP, Araya J, Troncoso E, Vinet S, Freer J. Fourier transform infrared imaging and microscopy studies of Pinus radiata pulps regarding the simultaneous saccharification and fermentation process. Anal Chim Acta 2015; 866:10-20. [PMID: 25732688 DOI: 10.1016/j.aca.2015.01.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 01/12/2015] [Accepted: 01/15/2015] [Indexed: 10/24/2022]
Abstract
The distribution and chemical patterns of lignocellulosic components at microscopic scale and their effect on the simultaneous saccharification and fermentation process (SSF) in the production of bioethanol from Pinus radiata pulps were analyzed by the application of diverse microscopical techniques, including scanning electronic microscopy (SEM), confocal laser scanning microscopy (CLSM) and attenuated total reflectance (ATR) - Fourier transform infrared microspectroscopy. This last technique was accompanied with multivariate methods, including principal component analysis (PCA) and multivariate curve resolution with alternating least squares (MCR-ALS) to evaluate the distribution patterns and to generate pure spectra of the lignocellulosic components of fibers. The results indicate that the information obtained by the techniques is complementary (ultrastructure, confocality and chemical characterization) and that the distribution of components affects the SSF yield, identifying lignin coalescence droplets as a characteristic factor to increase the SSF yield. Therefore, multivariate analysis of the infrared spectra enabled the in situ identification of the cellulose, lignin and lignin-carbohydrates arrangements. These techniques could be used to investigate the lignocellulosic components distribution and consequently their recalcitrance in many applications where minimal sample manipulation and microscale chemical information is required.
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Affiliation(s)
- Rosario Del P Castillo
- Faculty of Pharmacy, University of Concepcion, Concepcion, Chile; Biotechnology Center, University of Concepcion, Concepcion, Chile.
| | - Juan Araya
- Faculty of Pharmacy, University of Concepcion, Concepcion, Chile; Biotechnology Center, University of Concepcion, Concepcion, Chile
| | - Eduardo Troncoso
- Consorcio Bioenercel S.A, University of Concepcion, Concepcion, Chile
| | - Silenne Vinet
- Biotechnology Center, University of Concepcion, Concepcion, Chile; Faculty of Chemical Sciences, University of Concepcion, Concepcion, Chile
| | - Juanita Freer
- Biotechnology Center, University of Concepcion, Concepcion, Chile; Faculty of Chemical Sciences, University of Concepcion, Concepcion, Chile
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44
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Saini JK, Agrawal R, Satlewal A, Saini R, Gupta R, Mathur A, Tuli D. Second generation bioethanol production at high gravity of pilot-scale pretreated wheat straw employing newly isolated thermotolerant yeast Kluyveromyces marxianus DBTIOC-35. RSC Adv 2015. [DOI: 10.1039/c5ra05792b] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Application of thermotolerant yeast Kluyveromyces marxianus DBTIOC-35 in SSF decreases overall process time, and increases productivity and yield by allowing elimination of presaccharification step and use of high biomass concentration, respectively.
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Affiliation(s)
- Jitendra Kumar Saini
- DBT-IOC Centre for Advanced Bio-Energy Research
- R & D Centre
- Indian Oil Corporation Ltd
- Faridabad-121007
- India
| | - Ruchi Agrawal
- DBT-IOC Centre for Advanced Bio-Energy Research
- R & D Centre
- Indian Oil Corporation Ltd
- Faridabad-121007
- India
| | - Alok Satlewal
- DBT-IOC Centre for Advanced Bio-Energy Research
- R & D Centre
- Indian Oil Corporation Ltd
- Faridabad-121007
- India
| | - Reetu Saini
- DBT-IOC Centre for Advanced Bio-Energy Research
- R & D Centre
- Indian Oil Corporation Ltd
- Faridabad-121007
- India
| | - Ravi Gupta
- DBT-IOC Centre for Advanced Bio-Energy Research
- R & D Centre
- Indian Oil Corporation Ltd
- Faridabad-121007
- India
| | - Anshu Mathur
- DBT-IOC Centre for Advanced Bio-Energy Research
- R & D Centre
- Indian Oil Corporation Ltd
- Faridabad-121007
- India
| | - Deepak Tuli
- DBT-IOC Centre for Advanced Bio-Energy Research
- R & D Centre
- Indian Oil Corporation Ltd
- Faridabad-121007
- India
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45
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Tofighi A, Mazaheri Assadi M, Asadirad MHA, Zare Karizi S. Bio-ethanol production by a novel autochthonous thermo-tolerant yeast isolated from wastewater. JOURNAL OF ENVIRONMENTAL HEALTH SCIENCE & ENGINEERING 2014; 12:107. [PMID: 25937930 PMCID: PMC4416319 DOI: 10.1186/2052-336x-12-107] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 07/09/2014] [Indexed: 06/02/2023]
Abstract
BACKGROUND It has been known for years that ethanol is a bio-fuel to replace fossil fuels. The ethanol industry requires the utilization of micro-organisms capable production with stresses. The purpose of present study was to isolate and characterize ethanologenic yeast with high potential application at high temperature to produce bio-ethanol. METHODS To isolate ethanologenic yeasts, wastewater samples from a starch producer plant in Varamin, Iran were used. The isolates were identified by molecular characterization. Characteristics of the isolated strains were determined at 30, 35, 40 and 45°C for 48 hours. RESULTS 50 yeast strains capable of growing well in agar plates in a temperature range of 30-45°C were isolated. Out of the isolated strains, only three strains were screened for their ability to grow at 45°C. Selected yeast, designated as AT-3 strain which showed efficient flocculation capabilities with higher ethanol production and grew faster as compared to the rest of strains in media with 180 g/L glucose at 35°C. The selected yeast was identified as a new strain of Saccharomyces cerevisiae and submitted to the Gene-Bank database. Its' optimum growth temperature was between 35 and 40°C. The results showed that during the bio-ethanol production 2.5 × 10(10) and 8.5 × 10(9) (CFU/mL) were a good indication of strain capability in heat tolerance. Also, ethanol produced at a raise of 6.9% and 6.85% (w/v) at 35 and 40°C, respectively, whereas glucose-to-ethanol conversion yield was about 75% of the theoretical value. CONCLUSIONS Results emphasized that the isolated strain identified as Saccharomyces cerevisiae. This specific strain has thermo-tolerant, osmo-tolerant, flocculating capabilities with potential for application in developing a low cost ethanol industry.
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Affiliation(s)
- Azadeh Tofighi
- />Department of Biology, Islamic Azad University, Varamin-Pishva Branch, Pishva, Iran
| | - Mahnaz Mazaheri Assadi
- />Departments of Biotechnology, Iranian Research Organization for Science and Technology, Tehran, Iran
| | | | - Shohreh Zare Karizi
- />Department of Biology, Islamic Azad University, Varamin-Pishva Branch, Pishva, Iran
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Doğan A, Demirci S, Aytekin AÖ, Şahin F. Improvements of tolerance to stress conditions by genetic engineering in Saccharomyces cerevisiae during ethanol production. Appl Biochem Biotechnol 2014; 174:28-42. [PMID: 24908051 DOI: 10.1007/s12010-014-1006-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2013] [Accepted: 05/29/2014] [Indexed: 02/07/2023]
Abstract
Saccharomyces cerevisiae, industrial yeast isolate, has been of great interest in recent years for fuel ethanol production. The ethanol yield and productivity depend on many inhibitory factors during the fermentation process such as temperature, ethanol, compounds released as the result of pretreatment procedures, and osmotic stress. An ideal strain should be able to grow under different stress conditions occurred at different fermentation steps. Development of tolerant yeast strains can be achieved by reprogramming pathways supporting the ethanol metabolism by regulating the energy balance and detoxicification processes. Complex gene interactions should be solved for an in-depth comprehension of the yeast stress tolerance mechanism. Genetic engineering as a powerful biotechnological tool is required to design new strategies for increasing the ethanol fermentation performance. Upregulation of stress tolerance genes by recombinant DNA technology can be a useful approach to overcome inhibitory situations. This review presents the application of several genetic engineering strategies to increase ethanol yield under different stress conditions including inhibitor tolerance, ethanol tolerance, thermotolerance, and osmotolerance.
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Affiliation(s)
- Ayşegül Doğan
- Department of Genetics and BioEngineering, Faculty of Engineering and Architecture, Yeditepe University, 26 Ağustos Campus, Kayisdagi cad., Kayisdagi, TR-34755, Istanbul, Turkey,
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Du R, Yan J, Feng Q, Li P, Zhang L, Chang S, Li S. A novel wild-type Saccharomyces cerevisiae strain TSH1 in scaling-up of solid-state fermentation of ethanol from sweet sorghum stalks. PLoS One 2014; 9:e94480. [PMID: 24736641 PMCID: PMC3988051 DOI: 10.1371/journal.pone.0094480] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Accepted: 03/16/2014] [Indexed: 11/18/2022] Open
Abstract
The rising demand for bioethanol, the most common alternative to petroleum-derived fuel used worldwide, has encouraged a feedstock shift to non-food crops to reduce the competition for resources between food and energy production. Sweet sorghum has become one of the most promising non-food energy crops because of its high output and strong adaptive ability. However, the means by which sweet sorghum stalks can be cost-effectively utilized for ethanol fermentation in large-scale industrial production and commercialization remains unclear. In this study, we identified a novel Saccharomyces cerevisiae strain, TSH1, from the soil in which sweet sorghum stalks were stored. This strain exhibited excellent ethanol fermentative capacity and ability to withstand stressful solid-state fermentation conditions. Furthermore, we gradually scaled up from a 500-mL flask to a 127-m3 rotary-drum fermenter and eventually constructed a 550-m3 rotary-drum fermentation system to establish an efficient industrial fermentation platform based on TSH1. The batch fermentations were completed in less than 20 hours, with up to 96 tons of crushed sweet sorghum stalks in the 550-m3 fermenter reaching 88% of relative theoretical ethanol yield (RTEY). These results collectively demonstrate that ethanol solid-state fermentation technology can be a highly efficient and low-cost solution for utilizing sweet sorghum, providing a feasible and economical means of developing non-food bioethanol.
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Affiliation(s)
- Ran Du
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, China
| | - Jianbin Yan
- School of Life Sciences, Tsinghua University, Beijing, China
| | - Quanzhou Feng
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, China
| | - Peipei Li
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, China
| | - Lei Zhang
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, China
| | - Sandra Chang
- Beijing Engineering Research Center for Biofuels, Beijing, China
| | - Shizhong Li
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, China
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Satomura A, Katsuyama Y, Miura N, Kuroda K, Tomio A, Bamba T, Fukusaki E, Ueda M. Acquisition of thermotolerant yeast Saccharomyces cerevisiae by breeding via stepwise adaptation. Biotechnol Prog 2013; 29:1116-23. [PMID: 24115578 DOI: 10.1002/btpr.1754] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 05/01/2013] [Indexed: 11/11/2022]
Abstract
A thermotolerant Saccharomyces cerevisiae yeast strain, YK60-1, was bred from a parental strain, MT8-1, via stepwise adaptation. YK60-1 grew at 40°C, a temperature at which MT8-1 could not grow at all. YK60-1 exhibited faster growth than MT8-1 at 30°C. To investigate the mechanisms how MT8-1 acquired thermotolerance, DNA microarray analysis was performed. The analysis revealed the induction of stress-responsive genes such as those encoding heat shock proteins and trehalose biosynthetic enzymes in YK60-1. Furthermore, nontargeting metabolome analysis showed that YK60-1 accumulated more trehalose, a metabolite that contributes to stress tolerance in yeast, than MT8-1. In conclusion, S. cerevisiae MT8-1 acquired thermotolerance by induction of specific stress-responsive genes and enhanced intracellular trehalose levels.
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Affiliation(s)
- Atsushi Satomura
- Div. of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
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Choi WY, Kang DH, Lee HY. Enhancement of the saccharification yields of Ulva pertusa kjellmann and rape stems by the high-pressure steam pretreatment process. BIOTECHNOL BIOPROC E 2013. [DOI: 10.1007/s12257-013-0033-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Ismail KSK, Sakamoto T, Hasunuma T, Kondo A. Time-based comparative transcriptomics in engineered xylose-utilizing Saccharomyces cerevisiae identifies temperature-responsive genes during ethanol production. J Ind Microbiol Biotechnol 2013; 40:1039-50. [PMID: 23748446 DOI: 10.1007/s10295-013-1293-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 05/14/2013] [Indexed: 01/07/2023]
Abstract
Agricultural residues comprising lignocellulosic materials are excellent sources of pentose sugar, which can be converted to ethanol as fuel. Ethanol production via consolidated bioprocessing requires a suitable microorganism to withstand the harsh fermentation environment of high temperature, high ethanol concentration, and exposure to inhibitors. We genetically enhanced an industrial Saccharomyces cerevisiae strain, sun049, enabling it to uptake xylose as the sole carbon source at high fermentation temperature. This strain was able to produce 13.9 g/l ethanol from 50 g/l xylose at 38 °C. To better understand the xylose consumption ability during long-term, high-temperature conditions, we compared by transcriptomics two fermentation conditions: high temperature (38 °C) and control temperature (30 °C) during the first 12 h of fermentation. This is the first long-term, time-based transcriptomics approach, and it allowed us to discover the role of heat-responsive genes when xylose is the sole carbon source. The results suggest that genes related to amino acid, cell wall, and ribosomal protein synthesis are down-regulated under heat stress. To allow cell stability and continuous xylose uptake in order to produce ethanol, hexose transporter HXT5, heat shock proteins, ubiquitin proteins, and proteolysis were all induced at high temperature. We also speculate that the strong relationship between high temperature and increased xylitol accumulation represents the cell's mechanism to protect itself from heat degradation.
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Affiliation(s)
- Ku Syahidah Ku Ismail
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai-cho, Nada, Kobe, 657-8501, Japan
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