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Enhanced production of xylitol from xylose by expression of Bacillus subtilis arabinose:H + symporter and Scheffersomyces stipitis xylose reductase in recombinant Saccharomyces cerevisiae. Enzyme Microb Technol 2017; 107:7-14. [DOI: 10.1016/j.enzmictec.2017.07.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 07/28/2017] [Accepted: 07/29/2017] [Indexed: 11/17/2022]
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52
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Oh EJ, Kwak S, Kim H, Jin YS. Transporter engineering for cellobiose fermentation under lower pH conditions by engineered Saccharomyces cerevisiae. BIORESOURCE TECHNOLOGY 2017; 245:1469-1475. [PMID: 28583406 DOI: 10.1016/j.biortech.2017.05.138] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Revised: 05/19/2017] [Accepted: 05/21/2017] [Indexed: 06/07/2023]
Abstract
The aim of this study was to engineer cellodextrin transporter 2 (CDT-2) from Neurospora crassa for improved cellobiose fermentation under lower pH conditions by Saccharomyces cerevisiae. Through directed evolution, a mutant CDT-2 capable of facilitating cellobiose fermentation under lower pH conditions was obtained. Specifically, a library of CDT-2 mutants with GFP fusion was screened by flow cytometry and then serial subcultured to isolate a CDT-2 mutant capable of transporting cellobiose under acidic conditions. The engineered S. cerevisiae expressing the isolated mutant CDT-2 (I96N/T487A) produced ethanol with a specific cellobiose consumption rate of 0.069g/gcell/h, which was 51% and 55% higher than those of the strains harboring wild-type CDT-1 and CDT-2 in a minimal medium with 2g/L of acetic acid.
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Affiliation(s)
- Eun Joong Oh
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Suryang Kwak
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Heejin Kim
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Yong-Su Jin
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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53
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Jin YS, Cate JHD. Metabolic engineering of yeast for lignocellulosic biofuel production. Curr Opin Chem Biol 2017; 41:99-106. [DOI: 10.1016/j.cbpa.2017.10.025] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 10/16/2017] [Accepted: 10/20/2017] [Indexed: 01/04/2023]
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54
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Xylose transport in yeast for lignocellulosic ethanol production: Current status. J Biosci Bioeng 2017; 125:259-267. [PMID: 29196106 DOI: 10.1016/j.jbiosc.2017.10.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 09/07/2017] [Accepted: 10/10/2017] [Indexed: 01/07/2023]
Abstract
Lignocellulosic ethanol has been considered as an alternative transportation fuel. Utilization of hemicellulosic fraction in lignocelluloses is crucial in economical production of lignocellulosic ethanol. However, this fraction has not efficiently been utilized by traditional yeast Saccharomyces cerevisiae. Genetically modified S. cerevisiae, which can utilize xylose, has several limitations including low ethanol yield, redox imbalance, and undesired metabolite formation similar to native xylose utilizing yeasts. Besides, xylose uptake is a major issue, where sugar transport system plays an important role. These genetically modified and wild-type yeast strains have further been engineered for improved xylose uptake. Various techniques have been employed to facilitate the xylose transportation in these strains. The present review is focused on the sugar transport machineries, mechanisms of xylose transport, limitations and how to deal with xylose transport for xylose assimilation in yeast cells. The recent advances in different techniques to facilitate the xylose transportation have also been discussed.
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55
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Jansen MLA, Bracher JM, Papapetridis I, Verhoeven MD, de Bruijn H, de Waal PP, van Maris AJA, Klaassen P, Pronk JT. Saccharomyces cerevisiae strains for second-generation ethanol production: from academic exploration to industrial implementation. FEMS Yeast Res 2017; 17:3868933. [PMID: 28899031 PMCID: PMC5812533 DOI: 10.1093/femsyr/fox044] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 06/15/2017] [Indexed: 11/18/2022] Open
Abstract
The recent start-up of several full-scale 'second generation' ethanol plants marks a major milestone in the development of Saccharomyces cerevisiae strains for fermentation of lignocellulosic hydrolysates of agricultural residues and energy crops. After a discussion of the challenges that these novel industrial contexts impose on yeast strains, this minireview describes key metabolic engineering strategies that have been developed to address these challenges. Additionally, it outlines how proof-of-concept studies, often developed in academic settings, can be used for the development of robust strain platforms that meet the requirements for industrial application. Fermentation performance of current engineered industrial S. cerevisiae strains is no longer a bottleneck in efforts to achieve the projected outputs of the first large-scale second-generation ethanol plants. Academic and industrial yeast research will continue to strengthen the economic value position of second-generation ethanol production by further improving fermentation kinetics, product yield and cellular robustness under process conditions.
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Affiliation(s)
- Mickel L. A. Jansen
- DSM Biotechnology Centre, Alexander Fleminglaan 1, 2613 AX Delft, The
Netherlands
| | - Jasmine M. Bracher
- Department of Biotechnology, Delft University of Technology, Van der Maasweg
9, 2629 HZ Delft, The Netherlands
| | - Ioannis Papapetridis
- Department of Biotechnology, Delft University of Technology, Van der Maasweg
9, 2629 HZ Delft, The Netherlands
| | - Maarten D. Verhoeven
- Department of Biotechnology, Delft University of Technology, Van der Maasweg
9, 2629 HZ Delft, The Netherlands
| | - Hans de Bruijn
- DSM Biotechnology Centre, Alexander Fleminglaan 1, 2613 AX Delft, The
Netherlands
| | - Paul P. de Waal
- DSM Biotechnology Centre, Alexander Fleminglaan 1, 2613 AX Delft, The
Netherlands
| | - Antonius J. A. van Maris
- Department of Biotechnology, Delft University of Technology, Van der Maasweg
9, 2629 HZ Delft, The Netherlands
| | - Paul Klaassen
- DSM Biotechnology Centre, Alexander Fleminglaan 1, 2613 AX Delft, The
Netherlands
| | - Jack T. Pronk
- Department of Biotechnology, Delft University of Technology, Van der Maasweg
9, 2629 HZ Delft, The Netherlands
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56
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Wang C, Li Y, Qiu C, Wang S, Ma J, Shen Y, Zhang Q, Du B, Ding Y, Bao X. Identification of Important Amino Acids in Gal2p for Improving the L-arabinose Transport and Metabolism in Saccharomyces cerevisiae. Front Microbiol 2017; 8:1391. [PMID: 28785254 PMCID: PMC5519586 DOI: 10.3389/fmicb.2017.01391] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 07/10/2017] [Indexed: 11/29/2022] Open
Abstract
Efficient and cost-effective bioethanol production from lignocellulosic materials requires co-fermentation of the main hydrolyzed sugars, including glucose, xylose, and L-arabinose. Saccharomyces cerevisiae is a glucose-fermenting yeast that is traditionally used for ethanol production. Fermentation of L-arabinose is also possible after metabolic engineering. Transport into the cell is the first and rate-limiting step for L-arabinose metabolism. The galactose permease, Gal2p, is a non-specific, endogenous monosaccharide transporter that has been shown to transport L-arabinose. However, Gal2p-mediated transport of L-arabinose occurs at a low efficiency. In this study, homologous modeling and L-arabinose docking were used to predict amino acids in Gal2p that are crucial for L-arabinose transport. Nine amino acid residues in Gal2p were identified and were the focus for site-directed mutagenesis. In the Gal2p transport-deficient chassis cells, the capacity for L-arabinose transport of the different Gal2p mutants was compared by testing growth rates using L-arabinose as the sole carbon source. Almost all the tested mutations affected L-arabinose transport capacity. Among them, F85 is a unique site. The F85S, F85G, F85C, and F85T point mutations significantly increased L-arabinose transport activities, while, the F85E and F85R mutations decreased L-arabinose transport activities compared to the Gal2p-expressing wild-type strain. These results verified F85 as a key residue in L-arabinose transport. The F85S mutation, having the most significant effect, elevated the exponential growth rate by 40%. The F85S mutation also improved xylose transport efficiency and weakened the glucose transport preference. Overall, enhancing the L-arabinose transport capacity further improved the L-arabinose metabolism of engineered S. cerevisiae.
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Affiliation(s)
- Chengqiang Wang
- College of Life Sciences/Shandong Key Laboratory of Agricultural Microbiology, Shandong Agricultural UniversityTai'an, China.,The State Key Laboratory of Microbial Technology/Environment Research Institute, Shandong UniversityJinan, China
| | - Yanwei Li
- The State Key Laboratory of Microbial Technology/Environment Research Institute, Shandong UniversityJinan, China
| | - Chenxi Qiu
- College of Life Sciences/Shandong Key Laboratory of Agricultural Microbiology, Shandong Agricultural UniversityTai'an, China.,The State Key Laboratory of Microbial Technology/Environment Research Institute, Shandong UniversityJinan, China
| | - Shihao Wang
- College of Life Sciences/Shandong Key Laboratory of Agricultural Microbiology, Shandong Agricultural UniversityTai'an, China.,The State Key Laboratory of Microbial Technology/Environment Research Institute, Shandong UniversityJinan, China
| | - Jinjin Ma
- College of Life Sciences/Shandong Key Laboratory of Agricultural Microbiology, Shandong Agricultural UniversityTai'an, China
| | - Yu Shen
- The State Key Laboratory of Microbial Technology/Environment Research Institute, Shandong UniversityJinan, China
| | - Qingzhu Zhang
- The State Key Laboratory of Microbial Technology/Environment Research Institute, Shandong UniversityJinan, China
| | - Binghai Du
- College of Life Sciences/Shandong Key Laboratory of Agricultural Microbiology, Shandong Agricultural UniversityTai'an, China
| | - Yanqin Ding
- College of Life Sciences/Shandong Key Laboratory of Agricultural Microbiology, Shandong Agricultural UniversityTai'an, China
| | - Xiaoming Bao
- The State Key Laboratory of Microbial Technology/Environment Research Institute, Shandong UniversityJinan, China.,College of Bioengineering, Qilu University of TechnologyJinan, China
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57
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Liu G, Li B, Li C, Yuan Y. Enhancement of Simultaneous Xylose and Glucose Utilization by Regulating ZWF1 and PGI1 in Saccharomyces Cerevisiae. ACTA ACUST UNITED AC 2017. [DOI: 10.1007/s12209-017-0048-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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58
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You Y, Li P, Lei F, Xing Y, Jiang J. Enhancement of ethanol production from green liquor-ethanol-pretreated sugarcane bagasse by glucose-xylose cofermentation at high solid loadings with mixed Saccharomyces cerevisiae strains. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:92. [PMID: 28413447 PMCID: PMC5390481 DOI: 10.1186/s13068-017-0771-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2017] [Accepted: 03/22/2017] [Indexed: 05/28/2023]
Abstract
BACKGROUND Efficient cofermentation of glucose and xylose is necessary for economically feasible bioethanol production from lignocellulosic biomass. Here, we demonstrate pretreatment of sugarcane bagasse (SCB) with green liquor (GL) combined with ethanol (GL-Ethanol) by adding different GL amounts. The common Saccharomyces cerevisiae (CSC) and thermophilic S. cerevisiae (TSC) strains were used and different yeast cell mass ratios (CSC to TSC) were compared. The simultaneous saccharification and cofermentation (SSF/SSCF) process was performed by 5-20% (w/v) dry substrate (DS) solid loadings to determine optimal conditions for the co-consumption of glucose and xylose. RESULTS Compared to previous studies that tested fermentation of glucose using only the CSC, we obtained higher ethanol yield and concentration (92.80% and 23.22 g/L) with 1.5 mL GL/g-DS GL-Ethanol-pretreated SCB at 5% (w/v) solid loading and a CSC-to-TSC yeast cell mass ratio of 1:2 (w/w). Using 10% (w/v) solid loading under the same conditions, the ethanol concentration increased to 42.53 g/L but the ethanol yield decreased to 84.99%. In addition, an increase in the solid loading up to a certain point led to an increase in the ethanol concentration from 1.5 mL GL/g-DS-pretreated SCB. The highest ethanol concentration (68.24 g/L) was obtained with 15% (w/v) solid loading, using a CSC-to-TSC yeast cell mass ratio of 1:3 (w/w). CONCLUSIONS GL-Ethanol pretreatment is a promising pretreatment method for improving both glucan and xylan conversion efficiencies of SCB. There was a competitive relationship between the two yeast strains, and the glucose and xylose utilization ability of the TSC was better than that of the CSC. Ethanol concentration was obviously increased at high solid loading, but the yield decreased as a result of an increase in the viscosity and inhibitor levels in the fermentation system. Finally, the SSCF of GL-Ethanol-pretreated SCB with mixed S. cerevisiae strains increased ethanol concentration and was an effective conversion process for ethanol production at high solid loading.
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Affiliation(s)
- Yanzhi You
- Department of Chemistry and Chemical Engineering, MOE Engineering Research Center of Forestry Biomass Materials and Bioenergy, Beijing Forestry University, Beijing, 100083 China
| | - Pengfei Li
- GuangXi Key Laboratory of Chemistry and Engineering of Forest Products, College of Chemistry and Chemical Engineering, Guangxi University for Nationalities, Nanning, 530006 China
| | - Fuhou Lei
- GuangXi Key Laboratory of Chemistry and Engineering of Forest Products, College of Chemistry and Chemical Engineering, Guangxi University for Nationalities, Nanning, 530006 China
| | - Yang Xing
- Department of Chemistry and Chemical Engineering, MOE Engineering Research Center of Forestry Biomass Materials and Bioenergy, Beijing Forestry University, Beijing, 100083 China
| | - Jianxin Jiang
- Department of Chemistry and Chemical Engineering, MOE Engineering Research Center of Forestry Biomass Materials and Bioenergy, Beijing Forestry University, Beijing, 100083 China
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59
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Li YJ, Wang MM, Chen YW, Wang M, Fan LH, Tan TW. Engineered yeast with a CO 2-fixation pathway to improve the bio-ethanol production from xylose-mixed sugars. Sci Rep 2017; 7:43875. [PMID: 28262754 PMCID: PMC5338314 DOI: 10.1038/srep43875] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 02/01/2017] [Indexed: 11/25/2022] Open
Abstract
Bio-ethanol production from lignocellulosic raw materials could serve as a sustainable potential for improving the supply of liquid fuels in face of the food-to-fuel competition and the growing energy demand. Xylose is the second abundant sugar of lignocelluloses hydrolysates, but its commercial-scale conversion to ethanol by fermentation is challenged by incomplete and inefficient utilization of xylose. Here, we use a coupled strategy of simultaneous maltose utilization and in-situ carbon dioxide (CO2) fixation to achieve efficient xylose fermentation by the engineered Saccharomyces cerevisiae. Our results showed that the introduction of CO2 as electron acceptor for nicotinamide adenine dinucleotide (NADH) oxidation increased the total ethanol productivity and yield at the expense of simultaneous maltose and xylose utilization. Our achievements present an innovative strategy using CO2 to drive and redistribute the central pathways of xylose to desirable products and demonstrate a possible breakthrough in product yield of sugars.
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Affiliation(s)
- Yun-Jie Li
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People’s Republic of China
- National Energy R&D Center for Biorefinery, Beijing, People’s Republic of China
- Beijing Key Laboratory of Bioprocess, Beijing, People’s Republic of China
| | - Miao-Miao Wang
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People’s Republic of China
- National Energy R&D Center for Biorefinery, Beijing, People’s Republic of China
- Beijing Key Laboratory of Bioprocess, Beijing, People’s Republic of China
| | - Ya-Wei Chen
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People’s Republic of China
- National Energy R&D Center for Biorefinery, Beijing, People’s Republic of China
- Beijing Key Laboratory of Bioprocess, Beijing, People’s Republic of China
| | - Meng Wang
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People’s Republic of China
- National Energy R&D Center for Biorefinery, Beijing, People’s Republic of China
- Beijing Key Laboratory of Bioprocess, Beijing, People’s Republic of China
| | - Li-Hai Fan
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People’s Republic of China
- National Energy R&D Center for Biorefinery, Beijing, People’s Republic of China
- Beijing Key Laboratory of Bioprocess, Beijing, People’s Republic of China
| | - Tian-Wei Tan
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People’s Republic of China
- National Energy R&D Center for Biorefinery, Beijing, People’s Republic of China
- Beijing Key Laboratory of Bioprocess, Beijing, People’s Republic of China
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60
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Li H, Shen Y, Wu M, Hou J, Jiao C, Li Z, Liu X, Bao X. Engineering a wild-type diploid Saccharomyces cerevisiae strain for second-generation bioethanol production. BIORESOUR BIOPROCESS 2016; 3:51. [PMID: 27942436 PMCID: PMC5122614 DOI: 10.1186/s40643-016-0126-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Accepted: 11/11/2016] [Indexed: 11/24/2022] Open
Abstract
Background The cost-effective production of second-generation bioethanol, which is made from lignocellulosic materials, has to face the following two problems: co-fermenting xylose with glucose and enhancing the strain’s tolerance to lignocellulosic inhibitors. Based on our previous study, the wild-type diploid Saccharomyces cerevisiae strain BSIF with robustness and good xylose metabolism genetic background was used as a chassis for constructing efficient xylose-fermenting industrial strains. The performance of the resulting strains in the fermentation of media with sugars and hydrolysates was investigated. Results The following two novel heterologous genes were integrated into the genome of the chassis cell: the mutant MGT05196N360F, which encodes a xylose-specific, glucose-insensitive transporter and is derived from the Meyerozyma guilliermondii transporter gene MGT05196, and Ru-xylA (where Ru represents the rumen), which encodes a xylose isomerase (XI) with higher activity in S. cerevisiae. Additionally, endogenous modifications were also performed, including the overproduction of the xylulokinase Xks1p and the non-oxidative PPP (pentose phosphate pathway), and the inactivation of the aldose reductase Gre3p and the alkaline phosphatase Pho13p. These rationally designed genetic modifications, combined with alternating adaptive evolutions in xylose and SECS liquor (the leach liquor of steam-exploding corn stover), resulted in a final strain, LF1, with excellent xylose fermentation and enhanced inhibitor resistance. The specific xylose consumption rate of LF1 reached as high as 1.089 g g−1 h−1 with xylose as the sole carbon source. Moreover, its highly synchronized utilization of xylose and glucose was particularly significant; 77.6% of xylose was consumed along with glucose within 12 h, and the ethanol yield was 0.475 g g−1, which is more than 93% of the theoretical yield. Additionally, LF1 performed well in fermentations with two different lignocellulosic hydrolysates. Conclusion The strain LF1 co-ferments glucose and xylose efficiently and synchronously. This result highlights the great potential of LF1 for the practical production of second-generation bioethanol. Electronic supplementary material The online version of this article (doi:10.1186/s40643-016-0126-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hongxing Li
- State Key Laboratory of Microbial Technology, Shandong University, Shan Da Nan Road 27, Jinan, 250100 China.,Shandong Provincial Key Laboratory of Microbial Engineering, Qi Lu University of Technology, Jinan, 250353 China
| | - Yu Shen
- State Key Laboratory of Microbial Technology, Shandong University, Shan Da Nan Road 27, Jinan, 250100 China
| | - Meiling Wu
- State Key Laboratory of Microbial Technology, Shandong University, Shan Da Nan Road 27, Jinan, 250100 China
| | - Jin Hou
- State Key Laboratory of Microbial Technology, Shandong University, Shan Da Nan Road 27, Jinan, 250100 China
| | - Chunlei Jiao
- State Key Laboratory of Microbial Technology, Shandong University, Shan Da Nan Road 27, Jinan, 250100 China
| | - Zailu Li
- Shandong Provincial Key Laboratory of Microbial Engineering, Qi Lu University of Technology, Jinan, 250353 China
| | - Xinli Liu
- Shandong Provincial Key Laboratory of Microbial Engineering, Qi Lu University of Technology, Jinan, 250353 China
| | - Xiaoming Bao
- State Key Laboratory of Microbial Technology, Shandong University, Shan Da Nan Road 27, Jinan, 250100 China.,Shandong Provincial Key Laboratory of Microbial Engineering, Qi Lu University of Technology, Jinan, 250353 China
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61
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Enabling glucose/xylose co-transport in yeast through the directed evolution of a sugar transporter. Appl Microbiol Biotechnol 2016; 100:10215-10223. [PMID: 27730335 DOI: 10.1007/s00253-016-7879-8] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 09/04/2016] [Accepted: 09/18/2016] [Indexed: 10/20/2022]
Abstract
The capacity to co-transport glucose and xylose into yeast has remained a technical challenge in the field. While significant efforts have been made in transporter engineering to increase xylose transport rates, glucose-based inhibition still limit most of these transporters. To address this issue, we further engineer sugar transporter proteins to remove glucose inhibition and enable glucose/xylose co-transport. Specifically, we start with our previously derived CiGXS1 FIM mutant strain and subjugate it to several rounds of mutagenesis and selection in a hexose metabolism null strain. Through this effort, we identify several mutations including N326H, a truncation in the C-terminal tail, I171F, and M40V as additionally dominant for reducing glucose inhibition. The resulting transporter shows substantially improved xylose transport rates in the presence of high quantities of glucose including up to 70 g/L glucose. Moreover, the resulting transporter enables co-utilization of glucose and xylose with glucose rates on par with a wild-type transporter and xylose rates exceeding that of glucose. These results demonstrate that major facilitator superfamily hexose transporters can be rewired into glucose-xylose co-transporters without functional inhibition by either substrate. These results enhance the potential of using lignocellulosic biomass as a feedstock for yeast.
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62
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Novy V, Brunner B, Müller G, Nidetzky B. Toward "homolactic" fermentation of glucose and xylose by engineered Saccharomyces cerevisiae harboring a kinetically efficient l-lactate dehydrogenase within pdc1-pdc5 deletion background. Biotechnol Bioeng 2016; 114:163-171. [PMID: 27426989 DOI: 10.1002/bit.26048] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 06/20/2016] [Accepted: 07/14/2016] [Indexed: 10/21/2022]
Abstract
l-Lactic acid is an important platform chemical and its production from the lignocellulosic sugars glucose and xylose is, therefore, of high interest. Tolerance to low pH and a generally high robustness make Saccharomyces cerevisiae a promising host for l-lactic acid fermentation but strain development for effective utilization of both sugars is an unsolved problem. The herein used S. cerevisiae strain IBB10B05 incorporates a NADH-dependent pathway for oxidoreductive xylose assimilation within CEN.PK113-7D background and was additionally evolved for accelerated xylose-to-ethanol fermentation. Selecting the Plasmodium falciparum l-lactate dehydrogenase (pfLDH) for its high kinetic efficiency, strain IBB14LA1 was derived from IBB10B05 by placing the pfldh gene at the pdc1 locus under control of the pdc1 promotor. Strain IBB14LA1_5 additionally had the pdc5 gene disrupted. With both strains, continued l-lactic acid formation from glucose or xylose, each at 50 g/L, necessitated stabilization of pH. Using calcium carbonate (11 g/L), anaerobic shaken bottle fermentations at pH ≥ 5 resulted in l-lactic acid yields (YLA ) of 0.67 g/g glucose and 0.80 g/g xylose for strain IBB14LA1_5. Only little xylitol was formed (≤0.08 g/g) and no ethanol. In pH stabilized aerobic conversions of glucose, strain IBB14LA1_5 further showed excellent l-lactic acid productivities (1.8 g/L/h) without losses in YLA (0.69 g/g glucose). In strain IBB14LA1, the YLA was lower (≤0.18 g/g glucose; ≤0.27 g/g xylose) due to ethanol as well as xylitol formation. Therefore, this study shows that a S. cerevisiae strain originally optimized for xylose-to-ethanol fermentation was useful to implement l-lactic acid production from glucose and xylose; and with the metabolic engineering strategy applied, advance toward homolactic fermentation of both sugars was made. Biotechnol. Bioeng. 2017;114: 163-171. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Vera Novy
- Graz University of Technology, Institute of Biotechnology and Biochemical Engineering, NAWI Graz, Petersgasse 12/I, 8010 Graz, Austria
| | - Bernd Brunner
- Graz University of Technology, Institute of Biotechnology and Biochemical Engineering, NAWI Graz, Petersgasse 12/I, 8010 Graz, Austria
| | - Gerdt Müller
- Graz University of Technology, Institute of Biotechnology and Biochemical Engineering, NAWI Graz, Petersgasse 12/I, 8010 Graz, Austria
| | - Bernd Nidetzky
- Graz University of Technology, Institute of Biotechnology and Biochemical Engineering, NAWI Graz, Petersgasse 12/I, 8010 Graz, Austria.,Austrian Centre of Industrial Biotechnology, Graz, Austria
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63
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Li H, Alper HS. Enabling xylose utilization in Yarrowia lipolytica for lipid production. Biotechnol J 2016; 11:1230-40. [PMID: 27367454 DOI: 10.1002/biot.201600210] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 06/09/2016] [Accepted: 01/14/2016] [Indexed: 11/11/2022]
Abstract
The conversion of lignocellulosic sugars, in particular xylose, is important for sustainable fuels and chemicals production. While the oleaginous yeast Yarrowia lipolytica is a strong candidate for lipid production, it is currently unable to effectively utilize xylose. By introducing a heterologous oxidoreductase pathway and enabling starvation adaptation, we obtained a Y. lipolytica strain, E26 XUS, that can use xylose as a sole carbon source and produce over 15 g/L of lipid in bioreactor fermentations (29.3% of theoretical yield) with a maximal lipid productivity of 0.19 g/L/h. Genomic sequencing and genetic analysis pointed toward increases in genomic copy number of the pathway and resulting elevated expression levels as the causative mutations underlying this improved phenotype. More broadly, many regions of the genome were duplicated during starvation of Yarrowia. This strain can form the basis for further engineering to enhance xylose catabolic rates and conversion. Finally, this study also reveals the flexibility and dynamic nature of the Y. lipolytica genome, and the means at which starvation can be used to induce genomic duplications.
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Affiliation(s)
- Haibo Li
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, USA
| | - Hal S Alper
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, USA. .,McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA.
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64
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Agu CV, Ujor V, Gopalan V, Ezeji TC. Use of Cupriavidus basilensis-aided bioabatement to enhance fermentation of acid-pretreated biomass hydrolysates by Clostridium beijerinckii. J Ind Microbiol Biotechnol 2016; 43:1215-26. [PMID: 27400988 DOI: 10.1007/s10295-016-1798-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 06/16/2016] [Indexed: 10/21/2022]
Abstract
Lignocellulose-derived microbial inhibitors (LDMICs) prevent efficient fermentation of Miscanthus giganteus (MG) hydrolysates to fuels and chemicals. To address this problem, we explored detoxification of pretreated MG biomass by Cupriavidus basilensis ATCC(®)BAA-699 prior to enzymatic saccharification. We document three key findings from our test of this strategy to alleviate LDMIC-mediated toxicity on Clostridium beijerinckii NCIMB 8052 during fermentation of MG hydrolysates. First, we demonstrate that growth of C. basilensis is possible on furfural, 5-hydroxymethyfurfural, cinnamaldehyde, 4-hydroxybenzaldehyde, syringaldehyde, vanillin, and ferulic, p-coumaric, syringic and vanillic acid, as sole carbon sources. Second, we report that C. basilensis detoxified and metabolized ~98 % LDMICs present in dilute acid-pretreated MG hydrolysates. Last, this bioabatement resulted in significant payoffs during acetone-butanol-ethanol (ABE) fermentation by C. beijerinckii: 70, 50 and 73 % improvement in ABE concentration, yield and productivity, respectively. Together, our results show that biological detoxification of acid-pretreated MG hydrolysates prior to fermentation is feasible and beneficial.
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Affiliation(s)
- Chidozie Victor Agu
- Department of Animal Sciences, Ohio State Agricultural Research and Development Center (OARDC), The Ohio State University, 305 Gerlaugh Hall, 1680 Madison Avenue, Wooster, OH, 44691, USA
| | - Victor Ujor
- Renewable Energy Program, Agricultural Technical Institute, The Ohio State University, 1328 Dover Road, Wooster, OH, 44691, USA
| | - Venkat Gopalan
- Department of Chemistry and Biochemistry, Center for RNA Biology, The Ohio State University, 484 West 12th Avenue, Columbus, OH, 43210, USA
| | - Thaddeus Chukwuemeka Ezeji
- Department of Animal Sciences, Ohio State Agricultural Research and Development Center (OARDC), The Ohio State University, 305 Gerlaugh Hall, 1680 Madison Avenue, Wooster, OH, 44691, USA.
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65
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Ledesma-Amaro R, Lazar Z, Rakicka M, Guo Z, Fouchard F, Coq AMCL, Nicaud JM. Metabolic engineering of Yarrowia lipolytica to produce chemicals and fuels from xylose. Metab Eng 2016; 38:115-124. [PMID: 27396355 DOI: 10.1016/j.ymben.2016.07.001] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Revised: 06/17/2016] [Accepted: 07/05/2016] [Indexed: 11/29/2022]
Abstract
Yarrowia lipolytica is a biotechnological chassis for the production of a range of products, such as microbial oils and organic acids. However, it is unable to consume xylose, the major pentose in lignocellulosic hydrolysates, which are considered a preferred carbon source for bioprocesses due to their low cost, wide abundance and high sugar content. Here, we engineered Y. lipolytica to metabolize xylose to produce lipids or citric acid. The overexpression of xylose reductase and xylitol dehydrogenase from Scheffersomyces stipitis were necessary but not sufficient to permit growth. The additional overexpression of the endogenous xylulokinase enabled identical growth as the wild type strain in glucose. This mutant was able to produce up to 80g/L of citric acid from xylose. Transferring these modifications to a lipid-overproducing strain boosted the production of lipids from xylose. This is the first step towards a consolidated bioprocess to produce chemicals and fuels from lignocellulosic materials.
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Affiliation(s)
- Rodrigo Ledesma-Amaro
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France.
| | - Zbigniew Lazar
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France; Department of Biotechnology and Food Microbiology, Wrocław University of Environmental and Life Sciences, Chełmońskiego Str. 37/41, 51-630 Wrocław, Poland
| | - Magdalena Rakicka
- Department of Biotechnology and Food Microbiology, Wrocław University of Environmental and Life Sciences, Chełmońskiego Str. 37/41, 51-630 Wrocław, Poland
| | - Zhongpeng Guo
- LISBP-Biocatalysis Group, INSA/INRA, Université de Toulouse, 135 Avenue de Rangueil, 31077 Toulouse, France; INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, 31400 Toulouse, France; CNRS, UMR5504, 31400 Toulouse, France
| | - Florian Fouchard
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Anne-Marie Crutz-Le Coq
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France.
| | - Jean-Marc Nicaud
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
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66
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Ko JK, Um Y, Woo HM, Kim KH, Lee SM. Ethanol production from lignocellulosic hydrolysates using engineered Saccharomyces cerevisiae harboring xylose isomerase-based pathway. BIORESOURCE TECHNOLOGY 2016; 209:290-6. [PMID: 26990396 DOI: 10.1016/j.biortech.2016.02.124] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 02/25/2016] [Accepted: 02/26/2016] [Indexed: 05/12/2023]
Abstract
The efficient co-fermentation of glucose and xylose is necessary for the economically feasible bioethanol production from lignocellulosic biomass. Even with xylose utilizing Saccharomyces cerevisiae, the efficiency of the lignocellulosic ethanol production remains suboptimal mainly due to the low conversion yield of xylose to ethanol. In this study, we evaluated the co-fermentation performances of SXA-R2P-E, a recently engineered isomerase-based xylose utilizing strain, in mixed sugars and in lignocellulosic hydrolysates. In a high-sugar fermentation with 70g/L of glucose and 40g/L of xylose, SXA-R2P-E produced 50g/L of ethanol with an yield of 0.43gethanol/gsugars at 72h. From dilute acid-pretreated hydrolysates of rice straw and hardwood (oak), the strain produced 18-21g/L of ethanol with among the highest yield of 0.43-0.46gethanol/gsugars ever reported. This study shows a highly promising potential of a xylose isomerase-expressing strain as an industrially relevant ethanol producer from lignocellulosic hydrolysates.
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Affiliation(s)
- Ja Kyong Ko
- Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Youngsoon Um
- Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Han Min Woo
- Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Kyoung Heon Kim
- Department of Biotechnology, Graduate School, Korea University, Seoul 02841, Republic of Korea
| | - Sun-Mi Lee
- Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea.
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67
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Behera S, Sharma NK, Arora R, Kumar S. Effect of Evolutionary Adaption on Xylosidase Activity in Thermotolerant Yeast Isolates Kluyveromyces marxianus NIRE-K1 and NIRE-K3. Appl Biochem Biotechnol 2016; 179:1143-54. [DOI: 10.1007/s12010-016-2055-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 03/15/2016] [Indexed: 02/02/2023]
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68
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Yang L, Lübeck M, Souroullas K, Lübeck PS. Co-consumption of glucose and xylose for organic acid production by Aspergillus carbonarius cultivated in wheat straw hydrolysate. World J Microbiol Biotechnol 2016; 32:57. [PMID: 26925619 DOI: 10.1007/s11274-016-2025-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 02/04/2016] [Indexed: 12/01/2022]
Abstract
Aspergillus carbonarius exhibits excellent abilities to utilize a wide range of carbon sources and to produce various organic acids. In this study, wheat straw hydrolysate containing high concentrations of glucose and xylose was used for organic acid production by A. carbonarius. The results indicated that A. carbonarius efficiently co-consumed glucose and xylose and produced various types of organic acids in hydrolysate adjusted to pH 7. The inhibitor tolerance of A. carbonarius to the hydrolysate at different pH values was investigated and compared using spores and recycled mycelia. This comparison showed a slight difference in the inhibitor tolerance of the spores and the recycled mycelia based on their growth patterns. Moreover, the wild-type and a glucose oxidase deficient (Δgox) mutant were compared for their abilities to produce organic acids using the hydrolysate and a defined medium. The two strains showed a different pattern of organic acid production in the hydrolysate where the Δgox mutant produced more oxalic acid but less citric acid than the wild-type, which was different from the results obtained in the defined medium This study demonstrates the feasibility of using lignocellulosic biomass for the organic acid production by A. carbonarius.
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Affiliation(s)
- Lei Yang
- Section for Sustainable Biotechnology, Department of Chemistry and Bioscience, Aalborg University Copenhagen, A. C. Meyers Vaenge 15, 2450, Copenhagen SV, Denmark
| | - Mette Lübeck
- Section for Sustainable Biotechnology, Department of Chemistry and Bioscience, Aalborg University Copenhagen, A. C. Meyers Vaenge 15, 2450, Copenhagen SV, Denmark
| | - Konstantinos Souroullas
- Section for Sustainable Biotechnology, Department of Chemistry and Bioscience, Aalborg University Copenhagen, A. C. Meyers Vaenge 15, 2450, Copenhagen SV, Denmark.,MEDOCHEMIE LTD, 1-10 Constantinoupoleos St., 3011, Limassol, Cyprus
| | - Peter S Lübeck
- Section for Sustainable Biotechnology, Department of Chemistry and Bioscience, Aalborg University Copenhagen, A. C. Meyers Vaenge 15, 2450, Copenhagen SV, Denmark.
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69
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Moysés DN, Reis VCB, de Almeida JRM, de Moraes LMP, Torres FAG. Xylose Fermentation by Saccharomyces cerevisiae: Challenges and Prospects. Int J Mol Sci 2016; 17:207. [PMID: 26927067 PMCID: PMC4813126 DOI: 10.3390/ijms17030207] [Citation(s) in RCA: 138] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 01/23/2016] [Accepted: 01/27/2016] [Indexed: 12/17/2022] Open
Abstract
Many years have passed since the first genetically modified Saccharomyces cerevisiae strains capable of fermenting xylose were obtained with the promise of an environmentally sustainable solution for the conversion of the abundant lignocellulosic biomass to ethanol. Several challenges emerged from these first experiences, most of them related to solving redox imbalances, discovering new pathways for xylose utilization, modulation of the expression of genes of the non-oxidative pentose phosphate pathway, and reduction of xylitol formation. Strategies on evolutionary engineering were used to improve fermentation kinetics, but the resulting strains were still far from industrial application. Lignocellulosic hydrolysates proved to have different inhibitors derived from lignin and sugar degradation, along with significant amounts of acetic acid, intrinsically related with biomass deconstruction. This, associated with pH, temperature, high ethanol, and other stress fluctuations presented on large scale fermentations led the search for yeasts with more robust backgrounds, like industrial strains, as engineering targets. Some promising yeasts were obtained both from studies of stress tolerance genes and adaptation on hydrolysates. Since fermentation times on mixed-substrate hydrolysates were still not cost-effective, the more selective search for new or engineered sugar transporters for xylose are still the focus of many recent studies. These challenges, as well as under-appreciated process strategies, will be discussed in this review.
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Affiliation(s)
- Danuza Nogueira Moysés
- Departamento de Biologia Celular, Universidade de Brasília, Brasília, DF 70910-900, Brazil.
- Petrobras Research and Development Center, Biotechnology Management, Rio de Janeiro, RJ 21941-915, Brazil.
| | | | - João Ricardo Moreira de Almeida
- Embrapa Agroenergia, Laboratório de Genética e Biotecnologia, Parque Estação Biológica s/n, Av. W3 Norte, Brasília, DF 70770-901, Brazil.
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70
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Evolved hexose transporter enhances xylose uptake and glucose/xylose co-utilization in Saccharomyces cerevisiae. Sci Rep 2016; 6:19512. [PMID: 26781725 PMCID: PMC4726032 DOI: 10.1038/srep19512] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 12/09/2015] [Indexed: 12/24/2022] Open
Abstract
Enhancing xylose utilization has been a major focus in Saccharomyces cerevisiae strain-engineering efforts. The incentive for these studies arises from the need to use all sugars in the typical carbon mixtures that comprise standard renewable plant-biomass-based carbon sources. While major advances have been made in developing utilization pathways, the efficient import of five carbon sugars into the cell remains an important bottleneck in this endeavor. Here we use an engineered S. cerevisiae BY4742 strain, containing an established heterologous xylose utilization pathway, and imposed a laboratory evolution regime with xylose as the sole carbon source. We obtained several evolved strains with improved growth phenotypes and evaluated the best candidate using genome resequencing. We observed remarkably few single nucleotide polymorphisms in the evolved strain, among which we confirmed a single amino acid change in the hexose transporter HXT7 coding sequence to be responsible for the evolved phenotype. The mutant HXT7(F79S) shows improved xylose uptake rates (Vmax = 186.4 ± 20.1 nmol•min−1•mg−1) that allows the S. cerevisiae strain to show significant growth with xylose as the sole carbon source, as well as partial co-utilization of glucose and xylose in a mixed sugar cultivation.
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71
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Kim SK, Chung D, Himmel ME, Bomble YJ, Westpheling J. Heterologous expression of family 10 xylanases from Acidothermus cellulolyticus enhances the exoproteome of Caldicellulosiruptor bescii and growth on xylan substrates. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:176. [PMID: 27555882 PMCID: PMC4994175 DOI: 10.1186/s13068-016-0588-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 08/15/2016] [Indexed: 05/20/2023]
Abstract
BACKGROUND The ability to deconstruct plant biomass without conventional pretreatment has made members of the genus Caldicellulosiruptor the target of investigation for the consolidated processing of lignocellulosic biomass to biofuels and bioproducts. These Gram-positive bacteria are hyperthermophilic anaerobes and the most thermophilic cellulolytic organisms so far described. They use both C5 and C6 sugars simultaneously and have the ability to grow well on xylan, a major component of plant cell walls. This is an important advantage for their use to efficiently convert biomass at yields sufficient for an industrial process. For commodity chemicals, yield from substrate is perhaps the most important economic factor. In an attempt to improve even further the ability of C. bescii to use xylan, we introduced two xylanases from Acidothermus cellulolyticus. Acel_0180 includes tandem carbohydrate-binding modules (CBM2 and CBM3) located at the C-terminus, one of which, CBM2, is not present in C. bescii. Also, the sequences of Xyn10A and Acel_0180 have very little homology with the GH10 domains present in C. bescii. For these reasons, we selected these xylanases as potential candidates for synergistic interaction with those in the C. bescii exoproteome. RESULTS Heterologous expression of two xylanases from Acidothermus cellulolyticus in Caldicellulosiruptor bescii resulted in a modest, but significant increase in the activity of the exoproteome of C. bescii on xylan substrates. Even though the increase in extracellular activity was modest, the ability of C. bescii to grow on these substrates was dramatically improved suggesting that the xylan substrate/microbe interaction substantially increased deconstruction over the secreted free enzymes alone. CONCLUSIONS We anticipate that the ability to efficiently use xylan, a major component of plant cell walls for conversion of plant biomass to products of interest, will allow the conversion of renewable, sustainable, and inexpensive plant feedstocks to products at high yields.
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Affiliation(s)
- Sun-Ki Kim
- Department of Genetics, University of Georgia, Athens, GA USA
- The BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Daehwan Chung
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO USA
- The BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Michael E. Himmel
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO USA
- The BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Yannick J. Bomble
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO USA
- The BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Janet Westpheling
- Department of Genetics, University of Georgia, Athens, GA USA
- The BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN USA
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72
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The Renaissance of Neurospora crassa: How a Classical Model System is Used for Applied Research. Fungal Biol 2016. [DOI: 10.1007/978-3-319-27951-0_3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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73
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Amore A, Ciesielski PN, Lin CY, Salvachúa D, Sànchez i Nogué V. Development of Lignocellulosic Biorefinery Technologies: Recent Advances and Current Challenges. Aust J Chem 2016. [DOI: 10.1071/ch16022] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Recent developments of the biorefinery concept are described within this review, which focuses on the efforts required to make the lignocellulosic biorefinery a sustainable and economically viable reality. Despite the major research and development endeavours directed towards this goal over the past several decades, the integrated production of biofuel and other bio-based products still needs to be optimized from both technical and economical perspectives. This review will highlight recent progress towards the optimization of the major biorefinery processes, including biomass pretreatment and fractionation, saccharification of sugars, and conversion of sugars and lignin into fuels and chemical precursors. In addition, advances in genetic modification of biomass structure and composition for the purpose of enhancing the efficacy of conversion processes, which is emerging as a powerful tool for tailoring biomass fated for the biorefinery, will be overviewed. The continual improvement of these processes and their integration in the format of a modern biorefinery is paving the way for a sustainable bio-economy which will displace large portions of petroleum-derived fuels and chemicals with renewable substitutes.
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74
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Combining C6 and C5 sugar metabolism for enhancing microbial bioconversion. Curr Opin Chem Biol 2015; 29:49-57. [DOI: 10.1016/j.cbpa.2015.09.008] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 09/09/2015] [Accepted: 09/15/2015] [Indexed: 11/18/2022]
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75
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Xylose-induced dynamic effects on metabolism and gene expression in engineered Saccharomyces cerevisiae in anaerobic glucose-xylose cultures. Appl Microbiol Biotechnol 2015; 100:969-85. [DOI: 10.1007/s00253-015-7038-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2015] [Revised: 09/14/2015] [Accepted: 09/22/2015] [Indexed: 12/27/2022]
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76
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Knoshaug EP, Vidgren V, Magalhães F, Jarvis EE, Franden MA, Zhang M, Singh A. Novel transporters from
Kluyveromyces marxianus
and
Pichia guilliermondii
expressed in
Saccharomyces cerevisiae
enable growth on
l
‐arabinose and
d
‐xylose. Yeast 2015; 32:615-28. [DOI: 10.1002/yea.3084] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 05/11/2015] [Accepted: 06/23/2015] [Indexed: 11/08/2022] Open
Affiliation(s)
- Eric P. Knoshaug
- National Renewable Energy Laboratory National Bioenergy Centre Golden CO USA
| | - Virve Vidgren
- VTT Technical Research Centre of Finland PO Box 1000 FI‐02044 VTT Finland
| | | | - Eric E. Jarvis
- National Renewable Energy Laboratory National Bioenergy Centre Golden CO USA
| | - Mary Ann Franden
- National Renewable Energy Laboratory National Bioenergy Centre Golden CO USA
| | - Min Zhang
- National Renewable Energy Laboratory National Bioenergy Centre Golden CO USA
| | - Arjun Singh
- National Renewable Energy Laboratory National Bioenergy Centre Golden CO USA
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Reznicek O, Facey S, de Waal P, Teunissen A, de Bont J, Nijland J, Driessen A, Hauer B. Improved xylose uptake in Saccharomyces cerevisiae
due to directed evolution of galactose permease Gal2 for sugar co-consumption. J Appl Microbiol 2015; 119:99-111. [DOI: 10.1111/jam.12825] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 04/01/2015] [Accepted: 04/08/2015] [Indexed: 12/19/2022]
Affiliation(s)
- O. Reznicek
- Institute of Technical Biochemistry; University of Stuttgart; Stuttgart Germany
| | - S.J. Facey
- Institute of Technical Biochemistry; University of Stuttgart; Stuttgart Germany
| | | | | | | | - J.G. Nijland
- Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology; Zernike Institute for Advanced Materials and Kluyver Centre for Genomics of Industrial Fermentation; University of Groningen; Groningen The Netherlands
| | - A.J.M. Driessen
- Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology; Zernike Institute for Advanced Materials and Kluyver Centre for Genomics of Industrial Fermentation; University of Groningen; Groningen The Netherlands
| | - B. Hauer
- Institute of Technical Biochemistry; University of Stuttgart; Stuttgart Germany
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78
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Chen Y, Huang W, Fu G, Guo J, Liu M, Guo X, Xiao DG. A genetic transformation protocol for the xylose-fermenting yeastSpathaspora passalidarum. Eng Life Sci 2015. [DOI: 10.1002/elsc.201400232] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Affiliation(s)
- Yefu Chen
- College of Biotechnology; Tianjin University of Science and Technology; Tianjin China
| | - Wenlian Huang
- College of Biotechnology; Tianjin University of Science and Technology; Tianjin China
| | - Gengxin Fu
- College of Biotechnology; Tianjin University of Science and Technology; Tianjin China
| | - Jian Guo
- College of Biotechnology; Tianjin University of Science and Technology; Tianjin China
| | - Mingming Liu
- College of Biotechnology; Tianjin University of Science and Technology; Tianjin China
| | - Xuewu Guo
- College of Biotechnology; Tianjin University of Science and Technology; Tianjin China
| | - Dong-Guang Xiao
- College of Biotechnology; Tianjin University of Science and Technology; Tianjin China
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79
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Functional Analysis of Two l-Arabinose Transporters from Filamentous Fungi Reveals Promising Characteristics for Improved Pentose Utilization in Saccharomyces cerevisiae. Appl Environ Microbiol 2015; 81:4062-70. [PMID: 25841015 DOI: 10.1128/aem.00165-15] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 03/31/2015] [Indexed: 11/20/2022] Open
Abstract
Limited uptake is one of the bottlenecks for l-arabinose fermentation from lignocellulosic hydrolysates in engineered Saccharomyces cerevisiae. This study characterized two novel l-arabinose transporters, LAT-1 from Neurospora crassa and MtLAT-1 from Myceliophthora thermophila. Although the two proteins share high identity (about 83%), they display different substrate specificities. Sugar transport assays using the S. cerevisiae strain EBY.VW4000 indicated that LAT-1 accepts a broad substrate spectrum. In contrast, MtLAT-1 appeared much more specific for l-arabinose. Determination of the kinetic properties of both transporters revealed that the Km values of LAT-1 and MtLAT-1 for l-arabinose were 58.12 ± 4.06 mM and 29.39 ± 3.60 mM, respectively, with corresponding Vmax values of 116.7 ± 3.0 mmol/h/g dry cell weight (DCW) and 10.29 ± 0.35 mmol/h/g DCW, respectively. In addition, both transporters were found to use a proton-coupled symport mechanism and showed only partial inhibition by d-glucose during l-arabinose uptake. Moreover, LAT-1 and MtLAT-1 were expressed in the S. cerevisiae strain BSW2AP containing an l-arabinose metabolic pathway. Both recombinant strains exhibited much faster l-arabinose utilization, greater biomass accumulation, and higher ethanol production than the control strain. In conclusion, because of higher maximum velocities and reduced inhibition by d-glucose, the genes for the two characterized transporters are promising targets for improved l-arabinose utilization and fermentation in S. cerevisiae.
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80
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Challenges for the production of bioethanol from biomass using recombinant yeasts. ADVANCES IN APPLIED MICROBIOLOGY 2015; 92:89-125. [PMID: 26003934 DOI: 10.1016/bs.aambs.2015.02.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Lignocellulose biomass, one of the most abundant renewable resources on the planet, is an alternative sustainable energy source for the production of second-generation biofuels. Energy in the form of simple or complex carbohydrates can be extracted from lignocellulose biomass and fermented by microorganisms to produce bioethanol. Despite 40 years of active and cutting-edge research invested into the development of technologies to produce bioethanol from lignocellulosic biomass, the process remains commercially unviable. This review describes the achievements that have been made in generating microorganisms capable of utilizing both simple and complex sugars from lignocellulose biomass and the fermentation of these sugars into ethanol. We also provide a discussion on the current "roadblocks" standing in the way of making second-generation bioethanol a commercially viable alternative to fossil fuels.
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81
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Vilela LDF, de Araujo VPG, Paredes RDS, Bon EPDS, Torres FAG, Neves BC, Eleutherio ECA. Enhanced xylose fermentation and ethanol production by engineered Saccharomyces cerevisiae strain. AMB Express 2015; 5:16. [PMID: 25852993 PMCID: PMC4385029 DOI: 10.1186/s13568-015-0102-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 02/09/2015] [Indexed: 11/10/2022] Open
Abstract
We have recently demonstrated that heterologous expression of a bacterial xylose isomerase gene (xylA) of Burkholderia cenocepacia enabled a laboratorial Saccharomyces cerevisiae strain to ferment xylose anaerobically, without xylitol accumulation. However, the recombinant yeast fermented xylose slowly. In this study, an evolutionary engineering strategy was applied to improve xylose fermentation by the xylA-expressing yeast strain, which involved sequential batch cultivation on xylose. The resulting yeast strain co-fermented glucose and xylose rapidly and almost simultaneously, exhibiting improved ethanol production and productivity. It was also observed that when cells were grown in a medium containing higher glucose concentrations before being transferred to fermentation medium, higher rates of xylose consumption and ethanol production were obtained, demonstrating that xylose utilization was not regulated by catabolic repression. Results obtained by qPCR demonstrate that the efficiency in xylose fermentation showed by the evolved strain is associated, to the increase in the expression of genes HXT2 and TAL1, which code for a low-affinity hexose transporter and transaldolase, respectively. The ethanol productivity obtained after the introduction of only one genetic modification and the submission to a one-stage process of evolutionary engineering was equivalent to those of strains submitted to extensive metabolic and evolutionary engineering, providing solid basis for future applications of this strategy in industrial strains.
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82
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Kim TY, Oh EJ, Jin YS, Oh MK. Improved resistance against oxidative stress of engineered cellobiose-fermenting Saccharomyces cerevisiae revealed by metabolite profiling. BIOTECHNOL BIOPROC E 2015. [DOI: 10.1007/s12257-014-0301-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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83
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Shin HY, Nijland JG, de Waal PP, de Jong RM, Klaassen P, Driessen AJM. An engineered cryptic Hxt11 sugar transporter facilitates glucose-xylose co-consumption in Saccharomyces cerevisiae. BIOTECHNOLOGY FOR BIOFUELS 2015; 8:176. [PMID: 26535057 PMCID: PMC4630928 DOI: 10.1186/s13068-015-0360-6] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 10/22/2015] [Indexed: 05/15/2023]
Abstract
BACKGROUND The yeast Saccharomyces cerevisiae is unable to ferment pentose sugars like d-xylose. Through the introduction of the respective metabolic pathway, S. cerevisiae is able to ferment xylose but first utilizes d-glucose before the d-xylose can be transported and metabolized. Low affinity d-xylose uptake occurs through the endogenous hexose (Hxt) transporters. For a more robust sugar fermentation, co-consumption of d-glucose and d-xylose is desired as d-xylose fermentation is in particular prone to inhibition by compounds present in pretreated lignocellulosic feedstocks. RESULTS Evolutionary engineering of a d-xylose-fermenting S. cerevisiae strain lacking the major transporter HXT1-7 and GAL2 genes yielded a derivative that shows improved growth on xylose because of the expression of a normally cryptic HXT11 gene. Hxt11 also supported improved growth on d-xylose by the wild-type strain. Further selection for glucose-insensitive growth on d-xylose employing a quadruple hexokinase deletion yielded mutations at N366 of Hxt11 that reversed the transporter specificity for d-glucose into d-xylose while maintaining high d-xylose transport rates. The Hxt11 mutant enabled the efficient co-fermentation of xylose and glucose at industrially relevant sugar concentrations when expressed in a strain lacking the HXT1-7 and GAL2 genes. CONCLUSIONS Hxt11 is a cryptic sugar transporter of S. cerevisiae that previously has not been associated with effective d-xylose transport. Mutagenesis of Hxt11 yielded transporters that show a better affinity for d-xylose as compared to d-glucose while maintaining high transport rates. d-glucose and d-xylose co-consumption is due to a redistribution of the sugar transport flux while maintaining the total sugar conversion rate into ethanol. This method provides a single transporter solution for effective fermentation on lignocellulosic feedstocks.
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Affiliation(s)
- Hyun Yong Shin
- />Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology, University of Groningen, Zernike Institute for Advanced Materials and Kluyver Centre for Genomics of Industrial Fermentation, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Jeroen G. Nijland
- />Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology, University of Groningen, Zernike Institute for Advanced Materials and Kluyver Centre for Genomics of Industrial Fermentation, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Paul P. de Waal
- />DSM Biotechnology Center, Alexander Fleminglaan 1, 2613 AX Delft, The Netherlands
| | - René M. de Jong
- />DSM Biotechnology Center, Alexander Fleminglaan 1, 2613 AX Delft, The Netherlands
| | - Paul Klaassen
- />DSM Biotechnology Center, Alexander Fleminglaan 1, 2613 AX Delft, The Netherlands
| | - Arnold J. M. Driessen
- />Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology, University of Groningen, Zernike Institute for Advanced Materials and Kluyver Centre for Genomics of Industrial Fermentation, Nijenborgh 7, 9747 AG Groningen, The Netherlands
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84
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Shen MH, Song H, Li BZ, Yuan YJ. Deletion of D-ribulose-5-phosphate 3-epimerase (RPE1) induces simultaneous utilization of xylose and glucose in xylose-utilizing Saccharomyces cerevisiae. Biotechnol Lett 2014; 37:1031-6. [PMID: 25548118 DOI: 10.1007/s10529-014-1759-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 12/15/2014] [Indexed: 11/30/2022]
Abstract
Simultaneous co-utilization of xylose and glucose is a key issue in engineering microbes for cellulosic ethanol production. We coupled xylose utilization with glucose metabolism by deletion of D-ribulose-5-phosphate 3-epimerase (RPE1) through pentose phosphate pathway flux. Simultaneous utilization of xylose and glucose then occurred in the engineered Saccharomyces cerevisiae strain with the xylose utilization pathway. Xylose consumption occurred at the beginning of glucose consumption by the engineered yeast without RPE1 in a mixed sugar fermentation. About 3.2 g xylose l(-1) was utilized simultaneously with consumption of 40.2 g glucose l(-1) under O2-limited conditions. In addition, an approximate ratio (~1:10) for xylose and glucose consumption was observed in the fermentation with different sugar concentration by the engineered strain without RPE1. Simultaneous utilization of xylose is realized by the coupling of glucose metabolism and xylose utilization through RPE1 deletion in xylose-utilizing S. cerevisiae.
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Affiliation(s)
- Ming-Hua Shen
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, People's Republic of China,
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85
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Sànchez Nogué V, Karhumaa K. Xylose fermentation as a challenge for commercialization of lignocellulosic fuels and chemicals. Biotechnol Lett 2014; 37:761-72. [DOI: 10.1007/s10529-014-1756-2] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 12/11/2014] [Indexed: 10/24/2022]
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86
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Stambuk BU. Biotechnology strategies with industrial fuel ethanol Saccharomyces cerevisiae strains for efficient 1st and 2nd generation bioethanol production from sugarcane. BMC Proc 2014. [PMCID: PMC4204079 DOI: 10.1186/1753-6561-8-s4-o36] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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87
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Zhu JQ, Qin L, Li BZ, Yuan YJ. Simultaneous saccharification and co-fermentation of aqueous ammonia pretreated corn stover with an engineered Saccharomyces cerevisiae SyBE005. BIORESOURCE TECHNOLOGY 2014; 169:9-18. [PMID: 25016219 DOI: 10.1016/j.biortech.2014.06.085] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 06/23/2014] [Accepted: 06/24/2014] [Indexed: 06/03/2023]
Abstract
Co-fermentation of glucose and xylose from lignocelluloses is an efficient approach to increasing ethanol production. Simultaneous saccharification and co-fermentation (SSCF) of corn stover pretreated with aqueous ammonia was performed using engineered yeast with xylose utilization pathway. Thus far, the effect of the several key factors on SSCF was investigated, including temperature, inoculation size, pre-hydrolysis and pH. Ethanol concentration was achieved to 36.5 g/L during SSCF process with 6% glucan loading. The addition of Tween 20 reduced enzyme loading, i.e., from 15 to 7.5 FPU/gglucan with the same final ethanol concentration. The ethanol concentration was achieved to 70.1g/L at 12% glucan loading. Yeast feeding, combined with substrate and enzyme feeding, was proved to be an efficient approach for SSCF with high solid loading.
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Affiliation(s)
- Jia-Qing Zhu
- Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin University, Tianjin 300072, PR China; Center of Synthetic Biology, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China
| | - Lei Qin
- Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin University, Tianjin 300072, PR China; Center of Synthetic Biology, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China
| | - Bing-Zhi Li
- Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin University, Tianjin 300072, PR China; Center of Synthetic Biology, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China.
| | - Ying-Jin Yuan
- Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin University, Tianjin 300072, PR China; Center of Synthetic Biology, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China
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88
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Single cell and in vivo analyses elucidate the effect of xylC lactonase during production of D-xylonate in Saccharomyces cerevisiae. Metab Eng 2014; 25:238-47. [DOI: 10.1016/j.ymben.2014.07.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 06/15/2014] [Accepted: 07/17/2014] [Indexed: 11/21/2022]
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89
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Xylose and xylose/glucose co-fermentation by recombinant Saccharomyces cerevisiae strains expressing individual hexose transporters. Enzyme Microb Technol 2014; 63:13-20. [DOI: 10.1016/j.enzmictec.2014.05.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 05/08/2014] [Accepted: 05/09/2014] [Indexed: 01/16/2023]
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90
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Wallace-Salinas V, Signori L, Li YY, Ask M, Bettiga M, Porro D, Thevelein JM, Branduardi P, Foulquié-Moreno MR, Gorwa-Grauslund M. Re-assessment of YAP1 and MCR1 contributions to inhibitor tolerance in robust engineered Saccharomyces cerevisiae fermenting undetoxified lignocellulosic hydrolysate. AMB Express 2014; 4:56. [PMID: 25147754 PMCID: PMC4105880 DOI: 10.1186/s13568-014-0056-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 06/19/2014] [Indexed: 11/10/2022] Open
Abstract
Development of robust yeast strains that can efficiently ferment lignocellulose-based feedstocks is one of the requirements for achieving economically feasible bioethanol production processes. With this goal, several genes have been identified as promising candidates to confer improved tolerance to S. cerevisiae. In most of the cases, however, the evaluation of the genetic modification was performed only in laboratory strains, that is, in strains that are known to be quite sensitive to various types of stresses. In the present study, we evaluated the effects of overexpressing genes encoding the transcription factor (YAP1) and the mitochondrial NADH-cytochrome b5 reductase (MCR1), either alone or in combination, in an already robust and xylose-consuming industrial strain of S. cerevisiae and evaluated the effect during the fermentation of undiluted and undetoxified spruce hydrolysate. Overexpression of either gene resulted in faster hexose catabolism, but no cumulative effect was observed with the simultaneous overexpression. The improved phenotype of MCR1 overexpression appeared to be related, at least in part, to a faster furaldehyde reduction capacity, indicating that this reductase may have a wider substrate range than previously reported. Unexpectedly a decreased xylose fermentation rate was also observed in YAP1 overexpressing strains and possible reasons behind this phenotype are discussed.
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91
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Zhou H, Lan T, Dien BS, Hector RE, Zhu JY. Comparisons of fiveSaccharomyces cerevisiaestrains for ethanol production from SPORL-pretreated lodgepole pine. Biotechnol Prog 2014; 30:1076-83. [DOI: 10.1002/btpr.1937] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 05/08/2014] [Indexed: 12/30/2022]
Affiliation(s)
- Haifeng Zhou
- School of Chemistry Chemical Eng.; South China University Technol.; Guangzhou China
- USDA Forest Service, Forest Products Laboratory; Madison WI
| | - Tianqing Lan
- School of Light Industry and Food Sciences; Kunming Polytechnic University; Kunming China
- USDA Forest Service, Forest Products Laboratory; Madison WI
| | - Bruce S. Dien
- USDA Agricultural Research Service; National Center for Agricultural Utilization Research; Peoria IL
| | - Ronald E. Hector
- USDA Agricultural Research Service; National Center for Agricultural Utilization Research; Peoria IL
| | - J. Y. Zhu
- USDA Forest Service, Forest Products Laboratory; Madison WI
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92
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Farwick A, Bruder S, Schadeweg V, Oreb M, Boles E. Engineering of yeast hexose transporters to transport D-xylose without inhibition by D-glucose. Proc Natl Acad Sci U S A 2014; 111:5159-64. [PMID: 24706835 PMCID: PMC3986176 DOI: 10.1073/pnas.1323464111] [Citation(s) in RCA: 204] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
All known D-xylose transporters are competitively inhibited by D-glucose, which is one of the major reasons hampering simultaneous fermentation of D-glucose and D-xylose, two primary sugars present in lignocellulosic biomass. We have set up a yeast growth-based screening system for mutant D-xylose transporters that are insensitive to the presence of D-glucose. All of the identified variants had a mutation at either a conserved asparagine residue in transmembrane helix 8 or a threonine residue in transmembrane helix 5. According to a homology model of the yeast hexose transporter Gal2 deduced from the crystal structure of the D-xylose transporter XylE from Escherichia coli, both residues are found in the same region of the protein and are positioned slightly to the extracellular side of the central sugar-binding pocket. Therefore, it is likely that alterations sterically prevent D-glucose but not D-xylose from entering the pocket. In contrast, changing amino acids that are supposed to directly interact with the C6 hydroxymethyl group of D-glucose negatively affected transport of both D-glucose and D-xylose. Determination of kinetic properties of the mutant transporters revealed that Gal2-N376F had the highest affinity for D-xylose, along with a moderate transport velocity, and had completely lost the ability to transport hexoses. These transporter versions should prove valuable for glucose-xylose cofermentation in lignocellulosic hydrolysates by Saccharomyces cerevisiae and other biotechnologically relevant organisms. Moreover, our data contribute to the mechanistic understanding of sugar transport because the decisive role of the conserved asparagine residue for determining sugar specificity has not been recognized before.
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Affiliation(s)
- Alexander Farwick
- Institute of Molecular Biosciences, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
| | - Stefan Bruder
- Institute of Molecular Biosciences, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
| | - Virginia Schadeweg
- Institute of Molecular Biosciences, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
| | - Mislav Oreb
- Institute of Molecular Biosciences, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
| | - Eckhard Boles
- Institute of Molecular Biosciences, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
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93
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Li J, Lin L, Li H, Tian C, Ma Y. Transcriptional comparison of the filamentous fungus Neurospora crassa growing on three major monosaccharides D-glucose, D-xylose and L-arabinose. BIOTECHNOLOGY FOR BIOFUELS 2014; 7:31. [PMID: 24581151 PMCID: PMC4015282 DOI: 10.1186/1754-6834-7-31] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 02/14/2014] [Indexed: 05/09/2023]
Abstract
BACKGROUND D-glucose, D-xylose and L-arabinose are the three major monosaccharides in plant cell walls. Complete utilization of all three sugars is still a bottleneck for second-generation cellulolytic bioethanol production, especially for L-arabinose. However, little is known about gene expression profiles during L-arabinose utilization in fungi and a comparison of the genome-wide fungal response to these three major monosaccharides has not yet been reported. RESULTS Using next-generation sequencing technology, we have analyzed the transcriptome of N. crassa grown on L-arabinose versus D-xylose, with D-glucose as the reference. We found that the gene expression profiles on L-arabinose were dramatically different from those on D-xylose. It appears that L-arabinose can rewire the fungal cell metabolic pathway widely and provoke the expression of many kinds of sugar transporters, hemicellulase genes and transcription factors. In contrast, many fewer genes, mainly related to the pentose metabolic pathway, were upregulated on D-xylose. The rewired metabolic response to L-arabinose was significantly different and wider than that under no carbon conditions, although the carbon starvation response was initiated on L-arabinose. Three novel sugar transporters were identified and characterized for their substrates here, including one glucose transporter GLT-1 (NCU01633) and two novel pentose transporters, XAT-1 (NCU01132), XYT-1 (NCU05627). One transcription factor associated with the regulation of hemicellulase genes, HCR-1 (NCU05064) was also characterized in the present study. CONCLUSIONS We conducted the first transcriptome analysis of Neurospora crassa grown on L-arabinose and performed a comparative analysis with cells grown on D-xylose and D-glucose, which deepens the understanding of the utilization of L-arabinose and D-xylose in filamentous fungi. The dataset generated by this research will be useful for mining target genes for D-xylose and L-arabinose utilization engineering and the novel sugar transportes identified are good targets for pentose untilization and biofuels production. Moreover, hemicellulase production by fungi could be improved by modifying the hemicellulase regulator discovered here.
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Affiliation(s)
- Jingen Li
- 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
| | - Liangcai Lin
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Huiyan Li
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Chaoguang Tian
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Yanhe Ma
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
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94
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Nijland JG, Shin HY, de Jong RM, de Waal PP, Klaassen P, Driessen AJM. Engineering of an endogenous hexose transporter into a specific D-xylose transporter facilitates glucose-xylose co-consumption in Saccharomyces cerevisiae. BIOTECHNOLOGY FOR BIOFUELS 2014; 7:168. [PMID: 25505932 PMCID: PMC4263072 DOI: 10.1186/s13068-014-0168-9] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 11/13/2014] [Indexed: 05/12/2023]
Abstract
BACKGROUND Engineering of Saccharomyces cerevisiae for the simultaneous utilization of hexose and pentose sugars is vital for cost-efficient cellulosic bioethanol production. This yeast lacks specific pentose transporters and depends on endogenous hexose transporters for low affinity pentose uptake. Consequently, engineered xylose-fermenting yeast strains first utilize D-glucose before D-xylose can be transported and metabolized. RESULTS We have used an evolutionary engineering approach that depends on a quadruple hexokinase deletion xylose-fermenting S. cerevisiae strain to select for growth on D-xylose in the presence of high D-glucose concentrations. This resulted in D-glucose-tolerant growth of the yeast of D-xylose. This could be attributed to mutations at N367 in the endogenous chimeric Hxt36 transporter, causing a defect in D-glucose transport while still allowing specific uptake of D-xylose. The Hxt36-N367A variant transports D-xylose with a high rate and improved affinity, enabling the efficient co-consumption of D-glucose and D-xylose. CONCLUSIONS Engineering of yeast endogenous hexose transporters provides an effective strategy to construct glucose-insensitive xylose transporters that are well integrated in the carbon metabolism regulatory network, and that can be used for efficient lignocellulosic bioethanol production.
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Affiliation(s)
- Jeroen G Nijland
- />Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology, University of Groningen, Zernike Institute for Advanced Materials and Kluyver Centre for Genomics of Industrial Fermentation, Groningen, The Netherlands
| | - Hyun Yong Shin
- />Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology, University of Groningen, Zernike Institute for Advanced Materials and Kluyver Centre for Genomics of Industrial Fermentation, Groningen, The Netherlands
| | - René M de Jong
- />DSM Biotechnology Center, Alexander Fleminglaan 1, 2613 AX Delft, The Netherlands
| | - Paul P de Waal
- />DSM Biotechnology Center, Alexander Fleminglaan 1, 2613 AX Delft, The Netherlands
| | - Paul Klaassen
- />DSM Biotechnology Center, Alexander Fleminglaan 1, 2613 AX Delft, The Netherlands
| | - Arnold JM Driessen
- />Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology, University of Groningen, Zernike Institute for Advanced Materials and Kluyver Centre for Genomics of Industrial Fermentation, Groningen, The Netherlands
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95
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Rewiring yeast sugar transporter preference through modifying a conserved protein motif. Proc Natl Acad Sci U S A 2013; 111:131-6. [PMID: 24344268 DOI: 10.1073/pnas.1311970111] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Utilization of exogenous sugars found in lignocellulosic biomass hydrolysates, such as xylose, must be improved before yeast can serve as an efficient biofuel and biochemical production platform. In particular, the first step in this process, the molecular transport of xylose into the cell, can serve as a significant flux bottleneck and is highly inhibited by other sugars. Here we demonstrate that sugar transport preference and kinetics can be rewired through the programming of a sequence motif of the general form G-G/F-XXX-G found in the first transmembrane span. By evaluating 46 different heterologously expressed transporters, we find that this motif is conserved among functional transporters and highly enriched in transporters that confer growth on xylose. Through saturation mutagenesis and subsequent rational mutagenesis, four transporter mutants unable to confer growth on glucose but able to sustain growth on xylose were engineered. Specifically, Candida intermedia gxs1 Phe(38)Ile(39)Met(40), Scheffersomyces stipitis rgt2 Phe(38) and Met(40), and Saccharomyces cerevisiae hxt7 Ile(39)Met(40)Met(340) all exhibit this phenotype. In these cases, primary hexose transporters were rewired into xylose transporters. These xylose transporters nevertheless remained inhibited by glucose. Furthermore, in the course of identifying this motif, novel wild-type transporters with superior monosaccharide growth profiles were discovered, namely S. stipitis RGT2 and Debaryomyces hansenii 2D01474. These findings build toward the engineering of efficient pentose utilization in yeast and provide a blueprint for reprogramming transporter properties.
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96
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Kim SR, Park YC, Jin YS, Seo JH. Strain engineering of Saccharomyces cerevisiae for enhanced xylose metabolism. Biotechnol Adv 2013; 31:851-61. [DOI: 10.1016/j.biotechadv.2013.03.004] [Citation(s) in RCA: 140] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 02/23/2013] [Accepted: 03/04/2013] [Indexed: 12/27/2022]
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97
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An assay for functional xylose transporters in Saccharomyces cerevisiae. Anal Biochem 2013; 442:241-8. [DOI: 10.1016/j.ab.2013.07.041] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2013] [Revised: 07/27/2013] [Accepted: 07/29/2013] [Indexed: 11/18/2022]
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98
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Zha J, Li BZ, Shen MH, Hu ML, Song H, Yuan YJ. Optimization of CDT-1 and XYL1 expression for balanced co-production of ethanol and xylitol from cellobiose and xylose by engineered Saccharomyces cerevisiae. PLoS One 2013; 8:e68317. [PMID: 23844185 PMCID: PMC3699558 DOI: 10.1371/journal.pone.0068317] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 05/28/2013] [Indexed: 11/19/2022] Open
Abstract
Production of ethanol and xylitol from lignocellulosic hydrolysates is an alternative to the traditional production of ethanol in utilizing biomass. However, the conversion efficiency of xylose to xylitol is restricted by glucose repression, causing a low xylitol titer. To this end, we cloned genes CDT-1 (encoding a cellodextrin transporter) and gh1-1 (encoding an intracellular β-glucosidase) from Neurospora crassa and XYL1 (encoding a xylose reductase that converts xylose into xylitol) from Scheffersomyces stipitis into Saccharomyces cerevisiae, enabling simultaneous production of ethanol and xylitol from a mixture of cellobiose and xylose (main components of lignocellulosic hydrolysates). We further optimized the expression levels of CDT-1 and XYL1 by manipulating their promoters and copy-numbers, and constructed an engineered S. cerevisiae strain (carrying one copy of PGK1p-CDT1 and two copies of TDH3p-XYL1), which showed an 85.7% increase in xylitol production from the mixture of cellobiose and xylose than that from the mixture of glucose and xylose. Thus, we achieved a balanced co-fermentation of cellobiose (0.165 g/L/h) and xylose (0.162 g/L/h) at similar rates to co-produce ethanol (0.36 g/g) and xylitol (1.00 g/g).
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Affiliation(s)
- Jian Zha
- Key Laboratory of Systems Bioengineering (Tianjin University), Ministry of Education, Department of Pharmaceutical Engineering, School of Chemical Engineering & Technology, Tianjin University, Tianjin, P. R. China
| | - Bing-Zhi Li
- Key Laboratory of Systems Bioengineering (Tianjin University), Ministry of Education, Department of Pharmaceutical Engineering, School of Chemical Engineering & Technology, Tianjin University, Tianjin, P. R. China
| | - Ming-Hua Shen
- Key Laboratory of Systems Bioengineering (Tianjin University), Ministry of Education, Department of Pharmaceutical Engineering, School of Chemical Engineering & Technology, Tianjin University, Tianjin, P. R. China
| | - Meng-Long Hu
- Key Laboratory of Systems Bioengineering (Tianjin University), Ministry of Education, Department of Pharmaceutical Engineering, School of Chemical Engineering & Technology, Tianjin University, Tianjin, P. R. China
| | - Hao Song
- Key Laboratory of Systems Bioengineering (Tianjin University), Ministry of Education, Department of Pharmaceutical Engineering, School of Chemical Engineering & Technology, Tianjin University, Tianjin, P. R. China
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore
| | - Ying-Jin Yuan
- Key Laboratory of Systems Bioengineering (Tianjin University), Ministry of Education, Department of Pharmaceutical Engineering, School of Chemical Engineering & Technology, Tianjin University, Tianjin, P. R. China
- * E-mail:
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Demeke MM, Dietz H, Li Y, Foulquié-Moreno MR, Mutturi S, Deprez S, Den Abt T, Bonini BM, Liden G, Dumortier F, Verplaetse A, Boles E, Thevelein JM. Development of a D-xylose fermenting and inhibitor tolerant industrial Saccharomyces cerevisiae strain with high performance in lignocellulose hydrolysates using metabolic and evolutionary engineering. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:89. [PMID: 23800147 PMCID: PMC3698012 DOI: 10.1186/1754-6834-6-89] [Citation(s) in RCA: 189] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 06/12/2013] [Indexed: 05/04/2023]
Abstract
BACKGROUND The production of bioethanol from lignocellulose hydrolysates requires a robust, D-xylose-fermenting and inhibitor-tolerant microorganism as catalyst. The purpose of the present work was to develop such a strain from a prime industrial yeast strain, Ethanol Red, used for bioethanol production. RESULTS An expression cassette containing 13 genes including Clostridium phytofermentans XylA, encoding D-xylose isomerase (XI), and enzymes of the pentose phosphate pathway was inserted in two copies in the genome of Ethanol Red. Subsequent EMS mutagenesis, genome shuffling and selection in D-xylose-enriched lignocellulose hydrolysate, followed by multiple rounds of evolutionary engineering in complex medium with D-xylose, gradually established efficient D-xylose fermentation. The best-performing strain, GS1.11-26, showed a maximum specific D-xylose consumption rate of 1.1 g/g DW/h in synthetic medium, with complete attenuation of 35 g/L D-xylose in about 17 h. In separate hydrolysis and fermentation of lignocellulose hydrolysates of Arundo donax (giant reed), spruce and a wheat straw/hay mixture, the maximum specific D-xylose consumption rate was 0.36, 0.23 and 1.1 g/g DW inoculum/h, and the final ethanol titer was 4.2, 3.9 and 5.8% (v/v), respectively. In simultaneous saccharification and fermentation of Arundo hydrolysate, GS1.11-26 produced 32% more ethanol than the parent strain Ethanol Red, due to efficient D-xylose utilization. The high D-xylose fermentation capacity was stable after extended growth in glucose. Cell extracts of strain GS1.11-26 displayed 17-fold higher XI activity compared to the parent strain, but overexpression of XI alone was not enough to establish D-xylose fermentation. The high D-xylose consumption rate was due to synergistic interaction between the high XI activity and one or more mutations in the genome. The GS1.11-26 had a partial respiratory defect causing a reduced aerobic growth rate. CONCLUSIONS An industrial yeast strain for bioethanol production with lignocellulose hydrolysates has been developed in the genetic background of a strain widely used for commercial bioethanol production. The strain uses glucose and D-xylose with high consumption rates and partial cofermentation in various lignocellulose hydrolysates with very high ethanol yield. The GS1.11-26 strain shows highly promising potential for further development of an all-round robust yeast strain for efficient fermentation of various lignocellulose hydrolysates.
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Affiliation(s)
- Mekonnen M Demeke
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Belgium
- Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven, Heverlee, Flanders, Belgium
| | - Heiko Dietz
- Institute of Molecular Biosciences, Goethe-University Frankfurt, Max-von-Laue-Str. 9, D-60438 Frankfurt am Main, Germany
| | - Yingying Li
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Belgium
- Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven, Heverlee, Flanders, Belgium
| | - María R Foulquié-Moreno
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Belgium
- Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven, Heverlee, Flanders, Belgium
| | - Sarma Mutturi
- Department of Chemical Engineering, Lund University, P.O. Box 124, 22100 Lund, Sweden
| | - Sylvie Deprez
- Laboratory of Enzyme, Fermentation and Brewing Technology, KAHO Sint-Lieven University College, KU Leuven Association, Gebroeders De Smetstraat 1, 9000, Ghent, Flanders, Belgium
| | - Tom Den Abt
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Belgium
- Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven, Heverlee, Flanders, Belgium
| | - Beatriz M Bonini
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Belgium
- Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven, Heverlee, Flanders, Belgium
| | - Gunnar Liden
- Department of Chemical Engineering, Lund University, P.O. Box 124, 22100 Lund, Sweden
| | - Françoise Dumortier
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Belgium
- Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven, Heverlee, Flanders, Belgium
| | - Alex Verplaetse
- Laboratory of Enzyme, Fermentation and Brewing Technology, KAHO Sint-Lieven University College, KU Leuven Association, Gebroeders De Smetstraat 1, 9000, Ghent, Flanders, Belgium
| | - Eckhard Boles
- Institute of Molecular Biosciences, Goethe-University Frankfurt, Max-von-Laue-Str. 9, D-60438 Frankfurt am Main, Germany
| | - Johan M Thevelein
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Belgium
- Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven, Heverlee, Flanders, Belgium
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Nielsen J, Larsson C, van Maris A, Pronk J. Metabolic engineering of yeast for production of fuels and chemicals. Curr Opin Biotechnol 2013; 24:398-404. [DOI: 10.1016/j.copbio.2013.03.023] [Citation(s) in RCA: 235] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 03/18/2013] [Accepted: 03/27/2013] [Indexed: 01/01/2023]
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