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Zhang N, Shang Y, Wang F, Wang D, Hong J. Influence of prefoldin subunit 4 on the tolerance of Kluyveromyces marxianus to lignocellulosic biomass-derived inhibitors. Microb Cell Fact 2021; 20:224. [PMID: 34906148 PMCID: PMC8672639 DOI: 10.1186/s12934-021-01715-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 12/02/2021] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Kluyveromyces marxianus is a potentially excellent host for microbial cell factories using lignocellulosic biomass, due to its thermotolerance, high growth rate, and wide substrate spectrum. However, its tolerance to inhibitors derived from lignocellulosic biomass pretreatment needs to be improved. The prefoldin complex assists the folding of cytoskeleton which relates to the stress tolerance, moreover, several subunits of prefoldin have been verified to be involved in gene expression regulation. With the presence of inhibitors, the expression of a gene coding the subunit 4 of prefoldin (KmPFD4), a possible transcription factor, was significantly changed. Therefore, KmPFD4 was selected to evaluate its functions in inhibitors tolerance. RESULTS In this study, the disruption of the prefoldin subunit 4 gene (KmPFD4) led to increased concentration of intracellular reactive oxygen species (ROS) and disturbed the assembly of actin and tubulin in the presence of inhibitors, resulting in reduced inhibitor tolerance. Nuclear localization of KmPFD4 indicated that it could regulate gene expression. Transcriptomic analysis showed that upregulated gene expression related to ROS elimination, ATP production, and NAD+ synthesis, which is a response to the presence of inhibitors, disappeared in KmPFD4-disrupted cells. Thus, KmPFD4 impacts inhibitor tolerance by maintaining integration of the cytoskeleton and directly or indirectly affecting the expression of genes in response to inhibitors. Finally, overexpression of KmPFD4 enhanced ethanol fermentation with a 46.27% improvement in productivity in presence of the inhibitors. CONCLUSION This study demonstrated that KmPFD4 plays a positive role in the inhibitor tolerance and can be applied for the development of inhibitor-tolerant platform strains.
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Affiliation(s)
- Nini Zhang
- School of Life Sciences, University of Science and Technology of China, Hefei, 230027, Anhui, People's Republic of China
| | - Yingying Shang
- School of Life Sciences, University of Science and Technology of China, Hefei, 230027, Anhui, People's Republic of China
| | - Feier Wang
- School of Life Sciences, University of Science and Technology of China, Hefei, 230027, Anhui, People's Republic of China
| | - Dongmei Wang
- School of Life Sciences, University of Science and Technology of China, Hefei, 230027, Anhui, People's Republic of China.
- Biomedical Sciences and Health Laboratory of Anhui Province, University of Science & Technology of China, Hefei, 230027, China.
| | - Jiong Hong
- School of Life Sciences, University of Science and Technology of China, Hefei, 230027, Anhui, People's Republic of China.
- Hefei National Laboratory for Physical Science at the Microscale, Hefei, Anhui, 230026, People's Republic of China.
- Biomedical Sciences and Health Laboratory of Anhui Province, University of Science & Technology of China, Hefei, 230027, China.
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2
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Hoshida H, Kagawa S, Ogami K, Akada R. Anoxia-induced mitophagy in the yeast Kluyveromyces marxianus. FEMS Yeast Res 2021; 20:5932265. [PMID: 33130889 DOI: 10.1093/femsyr/foaa057] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 10/18/2020] [Indexed: 12/13/2022] Open
Abstract
Kluyveromyces marxianus is a thermotolerant, ethanol-producing yeast that requires oxygen for efficient ethanol fermentation. Under anaerobic conditions, glucose consumption and ethanol production are retarded, suggesting that oxygen affects the metabolic state of K. marxianus. Mitochondria require oxygen to function, and their forms and number vary according to environmental conditions. In this study, the effect of anoxia on mitochondrial behavior in K. marxianus was examined. Under aerobic growth conditions, mitochondria-targeted GFP exhibited a tubular and dotted localization, representing a typical mitochondrial morphology, but under anaerobic conditions, GFP localized in vacuoles, suggesting that mitophagy occurs under anaerobic conditions. To confirm mitophagy induction, the ATG32, ATG8, ATG11 and ATG19 genes were disrupted. Vacuolar localization of mitochondria-targeted GFP under anaerobic conditions was interrupted in the Δatg32 and Δatg8 strains but not the Δatg11 and Δatg19 strains. Electron microscopy revealed mitochondria-like membrane components in the vacuoles of wild-type cells grown under anaerobic conditions. Quantitative analyses using mitochondria-targeted Pho8 demonstrated that mitophagy was induced in K. marxianus by anoxia but not nitrogen starvation. To the best of our knowledge, this is the first demonstration of anoxia-induced mitophagy in yeasts.
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Affiliation(s)
- Hisashi Hoshida
- Division of Applied Chemistry, Graduate School of Science and Technology for Innovation, Yamaguchi University, Ube 755-8611, Japan.,Research Center for Thermotolerant Microbial Resources, Yamaguchi University, Yamaguchi 753-8315, Japan.,Yamaguchi University Biomedical Engineering Center, Ube 755-8611, Japan
| | - Shota Kagawa
- Division of Applied Chemistry, Graduate School of Science and Technology for Innovation, Yamaguchi University, Ube 755-8611, Japan
| | - Kentaro Ogami
- Department of Applied Chemistry, Faculty of Engineering, Yamaguchi University, Ube 755-8611, Japan
| | - Rinji Akada
- Division of Applied Chemistry, Graduate School of Science and Technology for Innovation, Yamaguchi University, Ube 755-8611, Japan.,Research Center for Thermotolerant Microbial Resources, Yamaguchi University, Yamaguchi 753-8315, Japan.,Yamaguchi University Biomedical Engineering Center, Ube 755-8611, Japan
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3
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Karim A, Gerliani N, Aïder M. Kluyveromyces marxianus: An emerging yeast cell factory for applications in food and biotechnology. Int J Food Microbiol 2020; 333:108818. [PMID: 32805574 DOI: 10.1016/j.ijfoodmicro.2020.108818] [Citation(s) in RCA: 89] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 08/04/2020] [Accepted: 08/05/2020] [Indexed: 11/18/2022]
Abstract
Several yeasts, which are eukaryotic microorganisms, have long been used in different industries due to their potential applications, both for fermentation and for the production of specific metabolites. Kluyveromyces marxianus is one of the most auspicious nonconventional yeasts, generally isolated from wide-ranging natural habitats such as fermented traditional dairy products, kefir grain, sewage from sugar industries, sisal leaves, and plants. This is a food-grade yeast with various beneficial traits, such as rapid growth rate and thermotolerance that make it appealing for different industrial food and biotechnological applications. K. marxianus is a respiro-fermentative yeast likely to produce energy by either respiration or fermentation pathways. It generates a wide-ranging specific metabolites and could contribute to a variety of different food and biotechnological industries. Although Saccharomyces cerevisiae is the most widely used dominant representative in all aspects, many applications of K. marxianus in biotechnology, food and environment have only started to emerge nowadays; some of the most promising applications are reviewed here. The general physiology of K. marxianus is outlined, and then the different applications are discussed: first, the applications of K. marxianus in biotechnology, and then the recent advances and possible applications in food, feed and environmental industries. Finally, this review provides a discussion of the main challenges and some perspectives for targeted applications of K. marxianus in the modern food technology and applied biotechnology in order to exploit the full potential of this yeast which can be used as a cell factory with great efficiency.
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Affiliation(s)
- Ahasanul Karim
- Department of Soil Sciences and Agri-food Engineering, Université Laval, Quebec, QC G1V 0A6, Canada; Institute of Nutrition and Functional Foods (INAF), Université Laval, Quebec, QC G1V 0A6, Canada
| | - Natela Gerliani
- Department of Soil Sciences and Agri-food Engineering, Université Laval, Quebec, QC G1V 0A6, Canada; Institute of Nutrition and Functional Foods (INAF), Université Laval, Quebec, QC G1V 0A6, Canada
| | - Mohammed Aïder
- Department of Soil Sciences and Agri-food Engineering, Université Laval, Quebec, QC G1V 0A6, Canada; Institute of Nutrition and Functional Foods (INAF), Université Laval, Quebec, QC G1V 0A6, Canada.
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4
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Sun L, Wang L, Chen H. High Productivity Ethanol from Solid-State Fermentation of Steam-Exploded Corn Stover Using Zymomonas mobilis by N 2 Periodic Pulsation Process Intensification. Appl Biochem Biotechnol 2020; 192:466-481. [PMID: 32399840 DOI: 10.1007/s12010-020-03318-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 04/23/2020] [Indexed: 01/06/2023]
Abstract
Solid-state fermentation, featured by water-saving, eco-friendly and high concentration product, is a promising technology in lignocellulosic ethanol industry. However, in solid-state fermentation system, large gas content inside the substrate directly leads to high oxygen partial pressure and inhibits ethanol fermentation. Z. mobilis can produce ethanol from glucose near the theoretical maximum value, but this ethanol yield would be greatly decreased by high oxygen partial pressure during solid-state fermentation. In this study, we applied N2 periodic pulsation process intensification (NPPPI) to ethanol solid-state fermentation, which displaced air with N2 and provided a proper anaerobic environment for Z. mobilis. Based on the water state distribution, the promotion effects of NPPPI on low solid loading and solid-state fermentation were analyzed to confirm the different degrees of oxygen inhibition in ethanol solid-state fermentation. During the simultaneous saccharification solid-state fermentation, the NPPPI group achieved 45.29% ethanol yield improvement and 30.38% concentration improvement compared with the control group. NPPPI also effectively decreased 58.47% of glycerol and 84.24% of acetic acid production and increased the biomass of Z. mobilis. By coupling the peristaltic enzymatic hydrolysis and fed-batch culture, NPPPI made the ethanol yield and concentration reach 80.11% and 55.06 g/L, respectively, in solid-state fermentation.
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Affiliation(s)
- Lele Sun
- State Key Laboratory of Biochemical Engineering, Beijing Key Laboratory of Biomass Refining Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China
- University of Chinese Academy of Sciences, Beijing, 100190, People's Republic of China
| | - Lan Wang
- State Key Laboratory of Biochemical Engineering, Beijing Key Laboratory of Biomass Refining Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China.
| | - Hongzhang Chen
- State Key Laboratory of Biochemical Engineering, Beijing Key Laboratory of Biomass Refining Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China
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Optimization of pre-saccharification time during dSSF process in oat-hull bioethanol technology. 3 Biotech 2019; 9:455. [PMID: 31832302 DOI: 10.1007/s13205-019-1988-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 11/10/2019] [Indexed: 12/26/2022] Open
Abstract
This study suggests a mathematical description and the optimization of the pre-saccharification time during simultaneous saccharification and fermentation with delayed yeast inoculation (dSSF) to ensure the fastest and fullest possible conversion of a substrate into the target product-bioethanol. A pulp derived by alkaline delignification of oat hulls was used as a substrate. The pre-saccharification step of oat-hull pulp was performed at a solid loading of 60 g/L, at 46 ± 2 °C, using mixed enzymes CelloLux-A and BrewZyme BGX, the pre-saccharification time was 8, 15, 24, 39, 48 and 72 h. Afterwards, the reaction mixture was cooled to 28 °C, a 10% inoculum of Saccharomyces cerevisiae Y-1693 was seeded, and fermentation combined with saccharification. The optimum pre-saccharification time (inoculation time) under these conditions was found to be 24 h, thus providing the maximum hydrolysis of cellulose and hemicelluloses and the highest yield of bioethanol. The procedure suggested herein for determining the optimum pre-saccharification time can be used for other model substrates from lignocellulosic feedstocks.
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6
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Bušić A, Marđetko N, Kundas S, Morzak G, Belskaya H, Ivančić Šantek M, Komes D, Novak S, Šantek B. Bioethanol Production from Renewable Raw Materials and Its Separation and Purification: A Review. Food Technol Biotechnol 2018; 56:289-311. [PMID: 30510474 PMCID: PMC6233010 DOI: 10.17113/ftb.56.03.18.5546] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Production of biofuels from renewable feedstocks has captured considerable scientific attention since they could be used to supply energy and alternative fuels. Bioethanol is one of the most interesting biofuels due to its positive impact on the environment. Currently, it is mostly produced from sugar- and starch-containing raw materials. However, various available types of lignocellulosic biomass such as agricultural and forestry residues, and herbaceous energy crops could serve as feedstocks for the production of bioethanol, energy, heat and value-added chemicals. Lignocellulose is a complex mixture of carbohydrates that needs an efficient pretreatment to make accessible pathways to enzymes for the production of fermentable sugars, which after hydrolysis are fermented into ethanol. Despite technical and economic difficulties, renewable lignocellulosic raw materials represent low-cost feedstocks that do not compete with the food and feed chain, thereby stimulating the sustainability. Different bioprocess operational modes were developed for bioethanol production from renewable raw materials. Furthermore, alternative bioethanol separation and purification processes have also been intensively developed. This paper deals with recent trends in the bioethanol production as a fuel from different renewable raw materials as well as with its separation and purification processes.
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Affiliation(s)
- Arijana Bušić
- University of Zagreb, Faculty of Food Technology and Biotechnology, Pierottijeva 6, HR-10000 Zagreb, Croatia
| | - Nenad Marđetko
- University of Zagreb, Faculty of Food Technology and Biotechnology, Pierottijeva 6, HR-10000 Zagreb, Croatia
| | - Semjon Kundas
- Belarussian National Technical University, Power Plant Construction and Engineering Services Faculty, Nezavisimosti Ave. 150, BY-220013 Minsk, Belarus
| | - Galina Morzak
- Belarussian National Technical University, Mining Engineering and Engineering Ecology Faculty, Nezavisimosti Ave. 65, BY-220013 Minsk, Belarus
| | - Halina Belskaya
- Belarussian National Technical University, Mining Engineering and Engineering Ecology Faculty, Nezavisimosti Ave. 65, BY-220013 Minsk, Belarus
| | - Mirela Ivančić Šantek
- University of Zagreb, Faculty of Food Technology and Biotechnology, Pierottijeva 6, HR-10000 Zagreb, Croatia
| | - Draženka Komes
- University of Zagreb, Faculty of Food Technology and Biotechnology, Pierottijeva 6, HR-10000 Zagreb, Croatia
| | - Srđan Novak
- University of Zagreb, Faculty of Food Technology and Biotechnology, Pierottijeva 6, HR-10000 Zagreb, Croatia
| | - Božidar Šantek
- University of Zagreb, Faculty of Food Technology and Biotechnology, Pierottijeva 6, HR-10000 Zagreb, Croatia
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7
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Production and Optimization Techniques of Bioethanol from Withered Flowers of Allamanda schottii L. by Activated Dry Yeast. JOURNAL OF PURE AND APPLIED MICROBIOLOGY 2018. [DOI: 10.22207/jpam.12.2.57] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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8
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Larragoiti-Kuri J, Rivera-Toledo M, Cocho-Roldán J, Maldonado-Ruiz Esparza K, Le Borgne S, Pedraza-Segura L. Convenient Product Distribution for a Lignocellulosic Biorefinery: Optimization through Sustainable Indexes. Ind Eng Chem Res 2017. [DOI: 10.1021/acs.iecr.7b02101] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Javier Larragoiti-Kuri
- Ingeniería
y Ciencias QuímicasUniversidad Autónoma Metropolitana Cuajimalpa, 01120 México City, Mexico
| | - Martín Rivera-Toledo
- Ingeniería
y Ciencias QuímicasUniversidad Autónoma Metropolitana Cuajimalpa, 01120 México City, Mexico
| | - José Cocho-Roldán
- Ingeniería
y Ciencias QuímicasUniversidad Autónoma Metropolitana Cuajimalpa, 01120 México City, Mexico
| | | | - Sylvie Le Borgne
- Chemical
Sciences and Engineering, Universidad Iberoamericana, 01219 México
City, Mexico
| | - Lorena Pedraza-Segura
- Ingeniería
y Ciencias QuímicasUniversidad Autónoma Metropolitana Cuajimalpa, 01120 México City, Mexico
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9
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10
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A Bacterial Laccase for Enhancing Saccharification and Ethanol Fermentation of Steam-Pretreated Biomass. FERMENTATION-BASEL 2016. [DOI: 10.3390/fermentation2020011] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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11
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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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12
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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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13
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Asgher M, Bashir F, Iqbal HMN. A comprehensive ligninolytic pre-treatment approach from lignocellulose green biotechnology to produce bio-ethanol. Chem Eng Res Des 2014. [DOI: 10.1016/j.cherd.2013.09.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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14
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Camargo D, Gomes SD, Sene L. Ethanol production from sunflower meal biomass by simultaneous saccharification and fermentation (SSF) with Kluyveromyces marxianus ATCC 36907. Bioprocess Biosyst Eng 2014; 37:2235-42. [PMID: 24794173 DOI: 10.1007/s00449-014-1201-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 04/15/2014] [Indexed: 10/25/2022]
Abstract
The lignocellulosic materials are considered promising renewable resources for ethanol production, but improvements in the processes should be studied to reduce operating costs. Thus, the appropriate enzyme loading for cellulose saccharification is critical for process economics. This study aimed at evaluating the concentration of cellulase and β-glucosidase in the production of bioethanol by simultaneous saccharification and fermentation (SSF) of sunflower meal biomass. The sunflower biomass was pretreated with 6% H2SO4 (w/v), at 121 °C, for 20 min, for hemicellulose removal and delignificated with 1% NaOH. SSF was performed with Kluyveromyces marxianus ATCC 36907, at 38 °C, 150 rpm, for 72 h, with different enzyme concentrations (Cellulase Complex NS22086-10, 15 and 20 FPU/gsubstrate and β-Glucosidase NS22118, with a cellulase to β-glucosidase ratio of 1.5:1; 2:1 and 3:1). The best condition for ethanol production was cellulase 20 FPU/gsubstrate and β-glucosidase 13.3 CBU/gsubstrate, resulting in 27.88 g/L ethanol, yield of 0.47 g/g and productivity of 0.38 g/L h. Under this condition the highest enzymatic conversion of cellulose to glucose was attained (87.06%).
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Affiliation(s)
- Danielle Camargo
- Post-Graduate Program in Agricultural Engineering, PGEAGRI, Center of Exact and Technological Sciences, Western Paraná State University, Rua Universitária, 2069, Cascavel-PR, Cascavel, Paraná, CEP 85819-110, Brazil,
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15
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Ethanol from laccase-detoxified lignocellulose by the thermotolerant yeast Kluyveromyces marxianus—Effects of steam pretreatment conditions, process configurations and substrate loadings. Biochem Eng J 2013. [DOI: 10.1016/j.bej.2013.07.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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16
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Moreno AD, Ibarra D, Ballesteros I, González A, Ballesteros M. Comparing cell viability and ethanol fermentation of the thermotolerant yeast Kluyveromyces marxianus and Saccharomyces cerevisiae on steam-exploded biomass treated with laccase. BIORESOURCE TECHNOLOGY 2013; 135:239-45. [PMID: 23265821 DOI: 10.1016/j.biortech.2012.11.095] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 11/08/2012] [Accepted: 11/10/2012] [Indexed: 05/13/2023]
Abstract
In this study, the thermotolerant yeast Kluyveromyces marxianus CECT 10875 was compared to the industrial strain Saccharomyces cerevisiae Ethanol Red for lignocellulosic ethanol production. For it, whole slurry from steam-exploded wheat straw was used as raw material, and two process configurations, simultaneous saccharification and fermentation (SSF) and presaccharification and simultaneous saccharification and fermentation (PSSF), were evaluated. Compared to S. cerevisiae, which was able to produce ethanol in both process configurations, K. marxianus was inhibited, and neither growth nor ethanol production occurred during the processes. However, laccase treatment of the whole slurry removed specifically lignin phenols from the overall inhibitory compounds present in the slurry and triggered the fermentation by K. marxianus, attaining final ethanol concentrations and yields comparable to those obtained by S. cerevisiae.
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Affiliation(s)
- Antonio D Moreno
- IMDEA Energía, Biotechnological Processes for Energy Production Unit, Móstoles, Madrid 28935, Spain
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17
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Alkali and enzymatic delignification of sugarcane bagasse to expose cellulose polymers for saccharification and bio-ethanol production. INDUSTRIAL CROPS AND PRODUCTS 2013. [DOI: 10.1016/j.indcrop.2012.10.005] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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18
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Moreno AD, Ibarra D, Fernández JL, Ballesteros M. Different laccase detoxification strategies for ethanol production from lignocellulosic biomass by the thermotolerant yeast Kluyveromyces marxianus CECT 10875. BIORESOURCE TECHNOLOGY 2012; 106:101-9. [PMID: 22197073 DOI: 10.1016/j.biortech.2011.11.108] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Revised: 11/21/2011] [Accepted: 11/25/2011] [Indexed: 05/13/2023]
Abstract
In this work, laccase enzymes were evaluated to detoxify the whole slurry from steam-exploded wheat straw. For it, two different strategies, laccase treatment before or after enzymatic hydrolysis, were employed. The detoxification efficiency was analyzed on enzymatic hydrolysis and fermentation levels by the thermotolerant yeast Kluyveromyces marxianus. Laccases reduced phenolic compounds without affecting weak acids and furan derivates. A lower glucose recovery was observed when laccase treatments were carried out before enzymatic hydrolysis, phenomenon that was not showed after enzymatic hydrolysis. In contrast, both laccase treatment strategies enhanced ethanol concentrations, reducing significantly the lag phase of the yeast and allowing substrate loading increments of saccharification and fermentation broths.
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Affiliation(s)
- Antonio D Moreno
- Instituto IMDEA Energía, Biotechnological Processes for Energy Production Unit, Móstoles, Madrid 28933, Spain
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19
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Ding W, Xiao Z, Tang X, Deng K, Fu S, Jiang Y, Yuan L. Evolutionary engineering of yeast for closed-circulating ethanol fermentation in PDMS membrane bioreactor. Biochem Eng J 2012. [DOI: 10.1016/j.bej.2011.09.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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20
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Correlation of genomic and physiological traits of thermoanaerobacter species with biofuel yields. Appl Environ Microbiol 2011; 77:7998-8008. [PMID: 21948836 DOI: 10.1128/aem.05677-11] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Thermophilic anaerobic noncellulolytic Thermoanaerobacter species are of great biotechnological importance in cellulosic ethanol production due to their ability to produce high ethanol yields by simultaneous fermentation of hexose and pentose. Understanding the genome structure of these species is critical to improving and implementing these bacteria for possible biotechnological use in consolidated bioprocessing schemes (CBP) for cellulosic ethanol production. Here we describe a comparative genome analysis of two ethanologenic bacteria, Thermoanaerobacter sp. X514 and Thermoanaerobacter pseudethanolicus 39E. Compared to 39E, X514 has several unique key characteristics important to cellulosic biotechnology, including additional alcohol dehydrogenases and xylose transporters, modifications to pentose metabolism, and a complete vitamin B₁₂ biosynthesis pathway. Experimental results from growth, metabolic flux, and microarray gene expression analyses support genome sequencing-based predictions which help to explain the distinct differences in ethanol production between these strains. The availability of whole-genome sequence and comparative genomic analyses will aid in engineering and optimizing Thermoanaerobacter strains for viable CBP strategies.
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Dhaliwal SS, Oberoi HS, Sandhu SK, Nanda D, Kumar D, Uppal SK. Enhanced ethanol production from sugarcane juice by galactose adaptation of a newly isolated thermotolerant strain of Pichia kudriavzevii. BIORESOURCE TECHNOLOGY 2011; 102:5968-75. [PMID: 21398115 DOI: 10.1016/j.biortech.2011.02.015] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2010] [Revised: 02/01/2011] [Accepted: 02/04/2011] [Indexed: 05/14/2023]
Abstract
The thermotolerant yeast strain isolated from sugarcane juice through enrichment technique was identified as a strain of Pichiakudriavzevii (Issatchenkiaorientalis) through molecular characterization. The P. kudriavzevii cells adapted to galactose medium produced about 30% more ethanol from sugarcane juice than the non-adapted cells. The recycled cells could be used for four successive cycles without a significant drop in ethanol production. Fermentation in a laboratory fermenter with galactose adapted P. kudriavzevii cells at 40°C resulted in an ethanol concentration and productivity of 71.9 g L(-1) and 4.0 g L(-1)h(-1), respectively from sugarcane juice composed of about 14% (w/v) sucrose, 2% (w/v) glucose and 1% (w/v) fructose. In addition to ethanol, 3.30 g L(-1) arabitol and 4.19 g L(-1) glycerol were also produced, whereas sorbitol and xylitol were not formed during fermentation. Use of galactose adapted P. kudriavzevii cells for ethanol production from sugarcane juice holds potential for scale-up studies.
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Zhang J, Lynd LR. Ethanol production from paper sludge by simultaneous saccharification and co-fermentation using recombinant xylose-fermenting microorganisms. Biotechnol Bioeng 2010; 107:235-44. [PMID: 20506488 DOI: 10.1002/bit.22811] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Simultaneous saccharification and co-fermentation (SSCF) of waste paper sludge to ethanol was investigated using two recombinant xylose-fermenting microbes: Zymomonas mobilis 8b and Saccharomyces cerevisiae RWB222. S. cerevisiae RWB222 produced over 40 g/L ethanol with a yield of 0.39 g ethanol/g carbohydrate on paper sludge at 37 degrees C, while similar titers and yields were achieved by Z. mobilis 8b at 30 degrees C. Both S. cerevisiae RWB222 and Z. mobilis 8b exhibited decreasing cell viability at 37 degrees C when producing over 40 g/L ethanol. A high ethanol concentration can account for S. cerevisiae RWB222 viability loss, but ethanol concentration was not the only factor influencing Z. mobilis 8b viability loss at 37 degrees C. Over 3 g/L residual glucose was observed at the end of paper sludge SSCF by Z. mobilis 8b, and a statistical analysis revealed that a high calcium concentration originating from paper sludge, a high ethanol concentration, and a high temperature were the key interactive factors resulting in glucose accumulation. The highest ethanol yields were achieved by SSCF of paper sludge with S. cerevisiae RWB222 at 37 degrees C and Z. mobilis 8b at 30 degrees C. With good sugar consumption at 37 degrees C, S. cerevisiae RWB222 was able to gain an improvement in the polysaccharide to sugar yield compared to that at 30 degrees C, whereas Z. mobilis 8b at 30 degrees C had a lower polysaccharide to sugar yield, but a higher sugar to ethanol yield than S. cerevisiae. Both organisms under optimal conditions achieved a 19% higher overall conversion of paper sludge to ethanol than the non-xylose utilizing S. cerevisiae D5A at its optimal process temperature of 37 degrees C.
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Affiliation(s)
- Jiayi Zhang
- Chemical and Biochemical Engineering, Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA
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Watanabe I, Nakamura T, Shima J. Strategy for simultaneous saccharification and fermentation using a respiratory-deficient mutant of Candida glabrata for bioethanol production. J Biosci Bioeng 2010; 110:176-9. [DOI: 10.1016/j.jbiosc.2010.02.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 02/04/2010] [Accepted: 02/05/2010] [Indexed: 11/26/2022]
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Construction of a β-glucosidase expression system using the multistress-tolerant yeast Issatchenkia orientalis. Appl Microbiol Biotechnol 2010; 87:1841-53. [DOI: 10.1007/s00253-010-2629-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Revised: 04/16/2010] [Accepted: 04/18/2010] [Indexed: 10/19/2022]
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Aita GM, Kim M. Pretreatment Technologies for the Conversion of Lignocellulosic Materials to Bioethanol. ACS SYMPOSIUM SERIES 2010. [DOI: 10.1021/bk-2010-1058.ch008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Affiliation(s)
- Giovanna M. Aita
- Audubon Sugar Institute, Louisiana State University Agricultural Center, 3845 Hwy. 75, St. Gabriel, LA 70776
| | - Misook Kim
- Audubon Sugar Institute, Louisiana State University Agricultural Center, 3845 Hwy. 75, St. Gabriel, LA 70776
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High-temperature fermentation: how can processes for ethanol production at high temperatures become superior to the traditional process using mesophilic yeast? Appl Microbiol Biotechnol 2009; 85:861-7. [DOI: 10.1007/s00253-009-2248-5] [Citation(s) in RCA: 205] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Revised: 09/05/2009] [Accepted: 09/06/2009] [Indexed: 10/20/2022]
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Tomás-Pejó E, García-Aparicio M, Negro MJ, Oliva JM, Ballesteros M. Effect of different cellulase dosages on cell viability and ethanol production by Kluyveromyces marxianus in SSF processes. BIORESOURCE TECHNOLOGY 2009; 100:890-5. [PMID: 18722114 DOI: 10.1016/j.biortech.2008.07.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2008] [Revised: 07/03/2008] [Accepted: 07/12/2008] [Indexed: 05/23/2023]
Abstract
This study was aimed to study the effect of commercial cellulases (Celluclast 1.5 LFG) on Kluyveromyces marxianus CECT 10875 growth and ethanol production in SSF processes. Preliminary tests carried out in glucose (50 g/L) fermentation medium showed that high enzyme amounts (2.5-3.5 FPU/mL) could cause a negative effect on K. marxianus growth rate and viable cells number. However, the maximum ethanol production was not affected and about 86% of the theoretical (22 g/L) was reached in all cases independently of the enzyme dosage. In SSF experiments, cell viability was always affected by enzyme loading. Nevertheless, slight differences observed on cell viability during glucose fermentation processes with the detected concentrations of the additives did not justify the negative effect observed in SSF experiments.
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Affiliation(s)
- E Tomás-Pejó
- Renewable Energies Department-CIEMAT, Avda. Complutense, 22 28040-Madrid, Spain.
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Suryawati L, Wilkins MR, Bellmer DD, Huhnke RL, Maness NO, Banat IM. Simultaneous saccharification and fermentation of Kanlow switchgrass pretreated by hydrothermolysis usingKluyveromyces marxianusIMB4. Biotechnol Bioeng 2008; 101:894-902. [DOI: 10.1002/bit.21965] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Olofsson K, Bertilsson M, Lidén G. A short review on SSF - an interesting process option for ethanol production from lignocellulosic feedstocks. BIOTECHNOLOGY FOR BIOFUELS 2008; 1:7. [PMID: 18471273 PMCID: PMC2397418 DOI: 10.1186/1754-6834-1-7] [Citation(s) in RCA: 231] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2008] [Accepted: 05/01/2008] [Indexed: 05/02/2023]
Abstract
Simultaneous saccharification and fermentation (SSF) is one process option for production of ethanol from lignocellulose. The principal benefits of performing the enzymatic hydrolysis together with the fermentation, instead of in a separate step after the hydrolysis, are the reduced end-product inhibition of the enzymatic hydrolysis, and the reduced investment costs. The principal drawbacks, on the other hand, are the need to find favorable conditions (e.g. temperature and pH) for both the enzymatic hydrolysis and the fermentation and the difficulty to recycle the fermenting organism and the enzymes. To satisfy the first requirement, the temperature is normally kept below 37 degrees C, whereas the difficulty to recycle the yeast makes it beneficial to operate with a low yeast concentration and at a high solid loading. In this review, we make a brief overview of recent experimental work and development of SSF using lignocellulosic feedstocks. Significant progress has been made with respect to increasing the substrate loading, decreasing the yeast concentration and co-fermentation of both hexoses and pentoses during SSF. Presently, an SSF process for e.g. wheat straw hydrolyzate can be expected to give final ethanol concentrations close to 40 g L-1 with a yield based on total hexoses and pentoses higher than 70%.
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Affiliation(s)
- Kim Olofsson
- Department of Chemical Engineering, Lund University, Box 124, 221 00 Lund, Sweden
| | - Magnus Bertilsson
- Department of Chemical Engineering, Lund University, Box 124, 221 00 Lund, Sweden
| | - Gunnar Lidén
- Department of Chemical Engineering, Lund University, Box 124, 221 00 Lund, Sweden
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Fonseca GG, Heinzle E, Wittmann C, Gombert AK. The yeast Kluyveromyces marxianus and its biotechnological potential. Appl Microbiol Biotechnol 2008; 79:339-54. [PMID: 18427804 DOI: 10.1007/s00253-008-1458-6] [Citation(s) in RCA: 306] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2008] [Revised: 03/12/2008] [Accepted: 03/13/2008] [Indexed: 11/26/2022]
Abstract
Strains belonging to the yeast species Kluyveromyces marxianus have been isolated from a great variety of habitats, which results in a high metabolic diversity and a substantial degree of intraspecific polymorphism. As a consequence, several different biotechnological applications have been investigated with this yeast: production of enzymes (beta-galactosidase, beta-glucosidase, inulinase, and polygalacturonases, among others), of single-cell protein, of aroma compounds, and of ethanol (including high-temperature and simultaneous saccharification-fermentation processes); reduction of lactose content in food products; production of bioingredients from cheese-whey; bioremediation; as an anticholesterolemic agent; and as a host for heterologous protein production. Compared to its congener and model organism, Kluyveromyces lactis, the accumulated knowledge on K. marxianus is much smaller and spread over a number of different strains. Although there is no publicly available genome sequence for this species, 20% of the CBS 712 strain genome was randomly sequenced (Llorente et al. in FEBS Lett 487:71-75, 2000). In spite of these facts, K. marxianus can envisage a great biotechnological future because of some of its qualities, such as a broad substrate spectrum, thermotolerance, high growth rates, and less tendency to ferment when exposed to sugar excess, when compared to K. lactis. To increase our knowledge on the biology of this species and to enable the potential applications to be converted into industrial practice, a more systematic approach, including the careful choice of (a) reference strain(s) by the scientific community, would certainly be of great value.
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Limtong S, Sringiew C, Yongmanitchai W. Production of fuel ethanol at high temperature from sugar cane juice by a newly isolated Kluyveromyces marxianus. BIORESOURCE TECHNOLOGY 2007; 98:3367-74. [PMID: 17537627 DOI: 10.1016/j.biortech.2006.10.044] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2006] [Revised: 10/05/2006] [Accepted: 10/19/2006] [Indexed: 05/07/2023]
Abstract
Kluyveromyces marxianus DMKU 3-1042, isolated by an enrichment technique in a sugar cane juice medium supplemented with 4% (w/v) ethanol at 35 degrees C, produced high concentrations of ethanol at both 40 and 45 degrees C. Ethanol production by this strain in shaking flask cultivation in sugar cane juice media at 37 degrees C was highest in a medium containing 22% total sugars, 0.05% (NH(4))(2)SO(4), 0.05% KH(2)PO(4), and 0.15% MgSO(4).7H(2)O and having a pH of 5.0; the ethanol concentration reached 8.7% (w/v), productivity 1.45 g/l/h and yield 77.5% of theoretical yield. At 40 degrees C, a maximal ethanol concentration of 6.78% (w/v), a productivity of 1.13 and a yield 60.4% of theoretical yield were obtained from the same medium, except that the pH was adjusted to 5.5. In a study on ethanol production in a 5l jar fermenter with an agitation speed of 300 rpm and an aeration rate of 0.2 vvm throughout the fermentation, K. marxianus DMKU 3-1042 yielded a final ethanol concentration of 6.43% (w/v), a productivity of 1.3g/l/h and a yield of 57.1% of theoretical yield.
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Affiliation(s)
- Savitree Limtong
- Department of Microbiology, Faculty of Science, Kasetsart University, Bangkok, Thailand.
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Ethanol from lignocellulosic materials by a simultaneous saccharification and fermentation process (SFS) with Kluyveromyces marxianus CECT 10875. Process Biochem 2004. [DOI: 10.1016/j.procbio.2003.09.011] [Citation(s) in RCA: 345] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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33
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Sun Y, Cheng J. Hydrolysis of lignocellulosic materials for ethanol production: a review. BIORESOURCE TECHNOLOGY 2002; 83:1-11. [PMID: 12058826 DOI: 10.1016/s0960-8524(01)00212-7] [Citation(s) in RCA: 2066] [Impact Index Per Article: 93.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Lignocellulosic biomass can be utilized to produce ethanol, a promising alternative energy source for the limited crude oil. There are mainly two processes involved in the conversion: hydrolysis of cellulose in the lignocellulosic biomass to produce reducing sugars, and fermentation of the sugars to ethanol. The cost of ethanol production from lignocellulosic materials is relatively high based on current technologies, and the main challenges are the low yield and high cost of the hydrolysis process. Considerable research efforts have been made to improve the hydrolysis of lignocellulosic materials. Pretreatment of lignocellulosic materials to remove lignin and hemicellulose can significantly enhance the hydrolysis of cellulose. Optimization of the cellulase enzymes and the enzyme loading can also improve the hydrolysis. Simultaneous saccharification and fermentation effectively removes glucose, which is an inhibitor to cellulase activity, thus increasing the yield and rate of cellulose hydrolysis.
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Affiliation(s)
- Ye Sun
- Department of Biological and Agricultural Engineering, North Carolina State University, Raleigh 27695-7625, USA
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Jamai L, Sendide K, Ettayebi K, Errachidi F, Hamdouni-Alami O, Tahri-Jouti MA, McDermott T, Ettayebi M. Physiological difference during ethanol fermentation between calcium alginate-immobilized Candida tropicalis and Saccharomyces cerevisiae. FEMS Microbiol Lett 2001; 204:375-9. [PMID: 11731151 DOI: 10.1111/j.1574-6968.2001.tb10913.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Calcium alginate-immobilized Candida tropicalis and Saccharomyces cerevisiae are compared for glucose fermentation. Immobilized C. tropicalis cells showed a slight morphological alteration during ethanol production at 40 degrees C, but their fermentation capacity was reduced by 25%. Under immobilization conditions, the two species demonstrated two different mathematical patterns when the relationship between growth rate, respiration rate, and ethanol tolerance was assessed. The interspecific difference in behavior of immobilized yeast cells is mainly due to their natural metabolic preference. The production of CO(2) by calcium alginate-immobilized C. tropicalis, as well as the lower supply of oxygen to the cells, are the major factors that reduce ethanol production.
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Affiliation(s)
- L Jamai
- Biotechnology Unit, University Sidi Mohamed Ben Abdallah, Atlas, Fes, Morocco
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35
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Wu Z, Lee YY. Nonisothermal simultaneous saccharification and fermentation for direct conversion of lignocellulosic biomass to ethanol. Appl Biochem Biotechnol 1998; 70-72:479-92. [DOI: 10.1007/bf02920161] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Banat IM, Singh D, Marchant R. The use of a thermotolerant fermentativeKluyveromyces marxianus IMB3 yeast strain for ethanol production. ACTA ACUST UNITED AC 1996. [DOI: 10.1002/abio.370160223] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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37
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Characterization and potential industrial applications of five novel, thermotolerant, fermentative, yeast strains. World J Microbiol Biotechnol 1995; 11:304-6. [DOI: 10.1007/bf00367104] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 01/06/1995] [Accepted: 01/13/1995] [Indexed: 10/26/2022]
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38
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Antonopoulos AA, Grohmann K. New research findings in biotechnology for fuels and chemical production. Appl Biochem Biotechnol 1994. [DOI: 10.1007/bf02941861] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Ballesteros I, Oliva JM, Carrasco JC, Ballesteros M. Effect of media supplementation on ethanol production by simultaneous saccharification and fermentation process. Appl Biochem Biotechnol 1994. [DOI: 10.1007/bf02941806] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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40
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Ballesteros I, Oliva JM, Ballesteros M, Carrasco J. Optimization of the simultaneous saccharification and fermentation process using thermotolerant yeasts. Appl Biochem Biotechnol 1993; 39-40:201-11. [PMID: 8323260 DOI: 10.1007/bf02918990] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Different treatments to improve the thermotolerance of fermenting yeasts for simultaneous ethanol saccharification and fermentation process of cellulosic materials have been examined. Yeasts of the genera Saccharomyces and Kluyveromyces were tested for growth and fermentation at progressively higher temperatures in the range of 42-47 degrees C. The best results were obtained with K. marxianus LG, which was then submitted to different treatments in order to achieve thermotolerant clones. A total of 35 new clones were obtained that dramatically improved the SSF of 10% Solka-floc substrate at 45 degrees C when compared to the original strain, some with ethanol concentrations as high as 33 g/L.
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Affiliation(s)
- I Ballesteros
- Instituto de Energias Renovables, CIEMAT Avda, Madrid, Spain
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41
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Deshpande MV. Ethanol production from cellulose by coupled saccharification/fermentation using Saccharomyces cerevisiae and cellulase complex from Sclerotium rolfsii UV-8 mutant. Appl Biochem Biotechnol 1992; 36:227-34. [PMID: 1288411 DOI: 10.1007/bf02921781] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Using cellulase/hemicellulase complex of Sclerotium rolfsii UV-8 mutant and Saccharomyces cerevisiae for fermentation, the coupled saccharification/fermentation (CSF) of 15% AT-rice straw was carried out at 40 degrees C, pH 4.5 for the first 24 h and further incubation was performed at 30 degrees C for 72 h. Increasing the amount of cellulase activity from 3-12 IU FPA/g of substrate resulted in increased yields of ethanol from 1.5-3.6% in 96 h. It has been observed that the coupled system was advantageous over the two stage (separate hydrolysis/fermentation) system as it produced higher amounts of ethanol from cellulose (3.6% as compared to 2.3% ethanol from rice straw).
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Affiliation(s)
- M V Deshpande
- Division of Biochemical Sciences, National Chemical Laboratory, Pune, India
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