1
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Li F, Bai W, Zhang Y, Zhang Z, Zhang D, Shen N, Yuan J, Zhao G, Wang X. Construction of an economical xylose-utilizing Saccharomyces cerevisiae and its ethanol fermentation. FEMS Yeast Res 2024; 24:foae001. [PMID: 38268490 PMCID: PMC10855017 DOI: 10.1093/femsyr/foae001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 01/03/2024] [Accepted: 01/23/2024] [Indexed: 01/26/2024] Open
Abstract
Traditional industrial Saccharomyces cerevisiae could not metabolize xylose due to the lack of a specific enzyme system for the reaction from xylose to xylulose. This study aims to metabolically remould industrial S. cerevisiae for the purpose of utilizing both glucose and xylose with high efficiency. Heterologous gene xylA from Piromyces and homologous genes related to xylose utilization were selected to construct expression cassettes and integrated into genome. The engineered strain was domesticated with industrial material under optimizing conditions subsequently to further improve xylose utilization rates. The resulting S. cerevisiae strain ABX0928-0630 exhibits a rapid growth rate and possesses near 100% xylose utilization efficiency to produce ethanol with industrial material. Pilot-scale fermentation indicated the predominant feature of ABX0928-0630 for industrial application, with ethanol yield of 0.48 g/g sugars after 48 hours and volumetric xylose consumption rate of 0.87 g/l/h during the first 24 hours. Transcriptome analysis during the modification and domestication process revealed a significant increase in the expression level of pathways associated with sugar metabolism and sugar sensing. Meanwhile, genes related to glycerol lipid metabolism exhibited a pattern of initial increase followed by a subsequent decrease, providing a valuable reference for the construction of efficient xylose-fermenting strains.
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Affiliation(s)
- Fan Li
- Nutrition and Health Research Institute, COFCO Corporation, No. 4 Road, South District, Beiqijia Town, Changping District, Beijing 102209, China
- COFCO Biochemical and Bioenergy (Zhaodong) Co., Ltd., No. 24, Zhaolan Road, Zhaodong City, Suihua, Heilongjiang 151100, China
- COFCO Corporation, COFCO Fortune Plaza, No.8, Chao Yang Men South St., Chao Yang District, Beijing 100020, China
| | - Wenxin Bai
- Nutrition and Health Research Institute, COFCO Corporation, No. 4 Road, South District, Beiqijia Town, Changping District, Beijing 102209, China
| | - Yuan Zhang
- Nutrition and Health Research Institute, COFCO Corporation, No. 4 Road, South District, Beiqijia Town, Changping District, Beijing 102209, China
- COFCO Corporation, COFCO Fortune Plaza, No.8, Chao Yang Men South St., Chao Yang District, Beijing 100020, China
| | - Zijian Zhang
- Nutrition and Health Research Institute, COFCO Corporation, No. 4 Road, South District, Beiqijia Town, Changping District, Beijing 102209, China
| | - Deguo Zhang
- COFCO Corporation, COFCO Fortune Plaza, No.8, Chao Yang Men South St., Chao Yang District, Beijing 100020, China
- COFCO Biotechnology Co., Ltd., No. 1, Zhongliang Avenue, Yuhui District, Bengbu, Anhui 233010, China
| | - Naidong Shen
- Nutrition and Health Research Institute, COFCO Corporation, No. 4 Road, South District, Beiqijia Town, Changping District, Beijing 102209, China
- COFCO Corporation, COFCO Fortune Plaza, No.8, Chao Yang Men South St., Chao Yang District, Beijing 100020, China
| | - Jingwei Yuan
- COFCO Biochemical and Bioenergy (Zhaodong) Co., Ltd., No. 24, Zhaolan Road, Zhaodong City, Suihua, Heilongjiang 151100, China
- COFCO Corporation, COFCO Fortune Plaza, No.8, Chao Yang Men South St., Chao Yang District, Beijing 100020, China
| | - Guomiao Zhao
- Nutrition and Health Research Institute, COFCO Corporation, No. 4 Road, South District, Beiqijia Town, Changping District, Beijing 102209, China
- COFCO Corporation, COFCO Fortune Plaza, No.8, Chao Yang Men South St., Chao Yang District, Beijing 100020, China
| | - Xiaoyan Wang
- Nutrition and Health Research Institute, COFCO Corporation, No. 4 Road, South District, Beiqijia Town, Changping District, Beijing 102209, China
- COFCO Corporation, COFCO Fortune Plaza, No.8, Chao Yang Men South St., Chao Yang District, Beijing 100020, China
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2
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Zhang Y, Gao J, Ma L, Tu L, Hu T, Wu X, Su P, Zhao Y, Liu Y, Li D, Zhou J, Yin Y, Tong Y, Zhao H, Lu Y, Wang J, Gao W, Huang L. Tandemly duplicated CYP82Ds catalyze 14-hydroxylation in triptolide biosynthesis and precursor production in Saccharomyces cerevisiae. Nat Commun 2023; 14:875. [PMID: 36797237 PMCID: PMC9936527 DOI: 10.1038/s41467-023-36353-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 01/27/2023] [Indexed: 02/18/2023] Open
Abstract
Triptolide is a valuable multipotent antitumor diterpenoid in Tripterygium wilfordii, and its C-14 hydroxyl group is often selected for modification to enhance both the bioavailability and antitumor efficacy. However, the mechanism for 14-hydroxylation formation remains unknown. Here, we discover 133 kb of tandem duplicated CYP82Ds encoding 11 genes on chromosome 12 and characterize CYP82D274 and CYP82D263 as 14-hydroxylases that catalyze the metabolic grid in triptolide biosynthesis. The two CYP82Ds catalyze the aromatization of miltiradiene, which has been repeatedly reported to be a spontaneous process. In vivo assays and evaluations of the kinetic parameters of CYP82Ds indicate the most significant affinity to dehydroabietic acid among multiple intermediates. The precursor 14-hydroxy-dehydroabietic acid is successfully produced by engineered Saccharomyces cerevisiae. Our study provides genetic elements for further elucidation of the downstream biosynthetic pathways and heterologous production of triptolide and of the currently intractable biosynthesis of other 14-hydroxyl labdane-type secondary metabolites.
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Affiliation(s)
- Yifeng Zhang
- State Key Laboratory of Dao-di Herbs, National Resource Center for Chinese Materia Medica, Chinese Academy of Chinese Medical Sciences, Beijing, China.,School of Traditional Chinese Medicine, Capital Medical University, Beijing, China.,Beijing Shijitan Hospital, Capital Medical University, Beijing, China
| | - Jie Gao
- State Key Laboratory of Dao-di Herbs, National Resource Center for Chinese Materia Medica, Chinese Academy of Chinese Medical Sciences, Beijing, China.,School of Traditional Chinese Medicine, Capital Medical University, Beijing, China
| | - Lin Ma
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, China
| | - Lichan Tu
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of Medicine, Zhejiang University City College, Hangzhou, China
| | - Tianyuan Hu
- School of Pharmacy, Hangzhou Normal University, Hangzhou, China
| | - Xiaoyi Wu
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, China
| | - Ping Su
- State Key Laboratory of Dao-di Herbs, National Resource Center for Chinese Materia Medica, Chinese Academy of Chinese Medical Sciences, Beijing, China
| | - Yujun Zhao
- State Key Laboratory of Dao-di Herbs, National Resource Center for Chinese Materia Medica, Chinese Academy of Chinese Medical Sciences, Beijing, China
| | - Yuan Liu
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, China
| | - Dan Li
- School of Pharmaceutical Sciences, Capital Medical University, Beijing, China
| | - Jiawei Zhou
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Yan Yin
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, China
| | - Yuru Tong
- School of Pharmaceutical Sciences, Capital Medical University, Beijing, China
| | - Huan Zhao
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, China
| | - Yun Lu
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, China
| | - Jiadian Wang
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, China
| | - Wei Gao
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, China. .,Beijing Shijitan Hospital, Capital Medical University, Beijing, China.
| | - Luqi Huang
- State Key Laboratory of Dao-di Herbs, National Resource Center for Chinese Materia Medica, Chinese Academy of Chinese Medical Sciences, Beijing, China.
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3
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Huang R, Zhang F, Zhou H, Yu H, Shen L, Jiang J, Qin Y, Liu Y, Song Y. Characterization of Trichoderma reesei endoglucanase displayed on the Saccharomyces cerevisiae cell surface and its effect on wine flavor in combination with β-glucosidase. Process Biochem 2022. [DOI: 10.1016/j.procbio.2022.11.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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4
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Son J, Joo JC, Baritugo KA, Jeong S, Lee JY, Lim HJ, Lim SH, Yoo JI, Park SJ. Consolidated microbial production of four-, five-, and six-carbon organic acids from crop residues: Current status and perspectives. BIORESOURCE TECHNOLOGY 2022; 351:127001. [PMID: 35292386 DOI: 10.1016/j.biortech.2022.127001] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 03/08/2022] [Accepted: 03/09/2022] [Indexed: 06/14/2023]
Abstract
The production of platform organic acids has been heavily dependent on petroleum-based industries. However, petrochemical-based industries that cannot guarantee a virtuous cycle of carbons released during various processes are now facing obsolescence because of the depletion of finite fossil fuel reserves and associated environmental pollutions. Thus, the transition into a circular economy in terms of the carbon footprint has been evaluated with the development of efficient microbial cell factories using renewable feedstocks. Herein, the recent progress on bio-based production of organic acids with four-, five-, and six-carbon backbones, including butyric acid and 3-hydroxybutyric acid (C4), 5-aminolevulinic acid and citramalic acid (C5), and hexanoic acid (C6), is discussed. Then, the current research on the production of C4-C6 organic acids is illustrated to suggest future directions for developing crop-residue based consolidated bioprocessing of C4-C6 organic acids using host strains with tailor-made capabilities.
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Affiliation(s)
- Jina Son
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Jeong Chan Joo
- Department of Biotechnology, The Catholic University of Korea, Bucheon-si, Gyeonggi-do 14662, Republic of Korea
| | - Kei-Anne Baritugo
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Seona Jeong
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Ji Yeon Lee
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Hye Jin Lim
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Seo Hyun Lim
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Jee In Yoo
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Si Jae Park
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea.
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5
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den Haan R, Rose SH, Cripwell RA, Trollope KM, Myburgh MW, Viljoen-Bloom M, van Zyl WH. Heterologous production of cellulose- and starch-degrading hydrolases to expand Saccharomyces cerevisiae substrate utilization: Lessons learnt. Biotechnol Adv 2021; 53:107859. [PMID: 34678441 DOI: 10.1016/j.biotechadv.2021.107859] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 10/14/2021] [Accepted: 10/15/2021] [Indexed: 12/28/2022]
Abstract
Selected strains of Saccharomyces cerevisiae are used for commercial bioethanol production from cellulose and starch, but the high cost of exogenous enzymes for substrate hydrolysis remains a challenge. This can be addressed through consolidated bioprocessing (CBP) where S. cerevisiae strains are engineered to express recombinant glycoside hydrolases during fermentation. Looking back at numerous strategies undertaken over the past four decades to improve recombinant protein production in S. cerevisiae, it is evident that various steps in the protein production "pipeline" can be manipulated depending on the protein of interest and its anticipated application. In this review, we briefly introduce some of the strategies and highlight lessons learned with regards to improved transcription, translation, post-translational modification and protein secretion of heterologous hydrolases. We examine how host strain selection and modification, as well as enzyme compatibility, are crucial determinants for overall success. Finally, we discuss how lessons from heterologous hydrolase expression can inform modern synthetic biology and genome editing tools to provide process-ready yeast strains in future. However, it is clear that the successful expression of any particular enzyme is still unpredictable and requires a trial-and-error approach.
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Affiliation(s)
- Riaan den Haan
- Department of Biotechnology, University of the Western Cape, Bellville, South Africa
| | - Shaunita H Rose
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | - Rosemary A Cripwell
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | - Kim M Trollope
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | - Marthinus W Myburgh
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | | | - Willem H van Zyl
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa.
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6
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Somasundaram S, Jeong J, Kumaravel A, Hong SH. Whole-Cell display of Pyrococcus horikoshii glutamate decarboxylase in Escherichia coli for high-titer extracellular gamma-aminobutyric acid production. J Ind Microbiol Biotechnol 2021; 48:6310578. [PMID: 34180519 PMCID: PMC8788790 DOI: 10.1093/jimb/kuab039] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 06/25/2021] [Indexed: 11/12/2022]
Abstract
We investigated the effect of cell-surface display of glutamate decarboxylase (GadB) on gamma-aminobutyric acid (GABA) production in recombinant Escherichia coli. We integrated GadB from the hyperthermophilic, anaerobic archaeon Pyrococcus horikoshii to the C-terminus of the E. coli outer membrane protein C (OmpC). After 12 hr of culturing GadB-displaying cells, the GABA concentration in the extracellular medium increased to 3.2 g/l, which is eight times that obtained with cells expressing GadB in the cytosol. To further enhance GABA production, we increased the temperatures of the culture. At 60°C, the obtained GABA concentration was 4.62 g/l after 12 hr of culture, and 5.35 g/l after 24 hr, which corresponds to a yield of 87.7%.
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Affiliation(s)
- Sivachandiran Somasundaram
- Department of Chemical Engineering, University of Ulsan, 93 Daehak-ro, Nam-gu, Ulsan 44610, Republic of Korea
| | - Jaehoon Jeong
- Department of Chemical Engineering, University of Ulsan, 93 Daehak-ro, Nam-gu, Ulsan 44610, Republic of Korea
| | - Ashokkumar Kumaravel
- Department of Chemical Engineering, University of Ulsan, 93 Daehak-ro, Nam-gu, Ulsan 44610, Republic of Korea
| | - Soon Ho Hong
- Department of Chemical Engineering, University of Ulsan, 93 Daehak-ro, Nam-gu, Ulsan 44610, Republic of Korea
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7
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Xie CY, Yang BX, Song QR, Xia ZY, Gou M, Tang YQ. Different transcriptional responses of haploid and diploid S. cerevisiae strains to changes in cofactor preference of XR. Microb Cell Fact 2020; 19:211. [PMID: 33187525 PMCID: PMC7666519 DOI: 10.1186/s12934-020-01474-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 11/07/2020] [Indexed: 01/27/2023] Open
Abstract
Background Xylitol accumulation is a major barrier for efficient ethanol production through heterologous xylose reductase-xylitol dehydrogenase (XR-XDH) pathway in recombinant Saccharomyces cerevisiae. Mutated NADH-preferring XR is usually employed to alleviate xylitol accumulation. However, it remains unclear how mutated XR affects the metabolic network for xylose metabolism. In this study, haploid and diploid strains were employed to investigate the transcriptional responses to changes in cofactor preference of XR through RNA-seq analysis during xylose fermentation. Results For the haploid strains, genes involved in xylose-assimilation (XYL1, XYL2, XKS1), glycolysis, and alcohol fermentation had higher transcript levels in response to mutated XR, which was consistent with the improved xylose consumption rate and ethanol yield. For the diploid strains, genes related to protein biosynthesis were upregulated while genes involved in glyoxylate shunt were downregulated in response to mutated XR, which might contribute to the improved yields of biomass and ethanol. When comparing the diploids with the haploids, genes involved in glycolysis and MAPK signaling pathway were significantly downregulated, while oxidative stress related transcription factors (TFs) were significantly upregulated, irrespective of the cofactor preference of XR. Conclusions Our results not only revealed the differences in transcriptional responses of the diploid and haploid strains to mutated XR, but also provided underlying basis for better understanding the differences in xylose metabolism between the diploid and haploid strains.
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Affiliation(s)
- Cai-Yun Xie
- College of Architecture and Environment, Sichuan University, No. 24, South Section 1, First Ring Road, Chengdu, 610065, Sichuan, China
| | - Bai-Xue Yang
- College of Architecture and Environment, Sichuan University, No. 24, South Section 1, First Ring Road, Chengdu, 610065, Sichuan, China
| | - Qing-Ran Song
- College of Architecture and Environment, Sichuan University, No. 24, South Section 1, First Ring Road, Chengdu, 610065, Sichuan, China
| | - Zi-Yuan Xia
- College of Architecture and Environment, Sichuan University, No. 24, South Section 1, First Ring Road, Chengdu, 610065, Sichuan, China
| | - Min Gou
- College of Architecture and Environment, Sichuan University, No. 24, South Section 1, First Ring Road, Chengdu, 610065, Sichuan, China.
| | - Yue-Qin Tang
- College of Architecture and Environment, Sichuan University, No. 24, South Section 1, First Ring Road, Chengdu, 610065, Sichuan, China.
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8
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Yukawa T, Bamba T, Guirimand G, Matsuda M, Hasunuma T, Kondo A. Optimization of 1,2,4-butanetriol production from xylose in Saccharomyces cerevisiae by metabolic engineering of NADH/NADPH balance. Biotechnol Bioeng 2020; 118:175-185. [PMID: 32902873 DOI: 10.1002/bit.27560] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 08/09/2020] [Accepted: 08/27/2020] [Indexed: 01/02/2023]
Abstract
1,2,4-Butanetriol (BT) is used as a precursor for the synthesis of various pharmaceuticals and the energetic plasticizer 1,2,4-butanetriol trinitrate. In Saccharomyces cerevisiae, BT is biosynthesized from xylose via heterologous four enzymatic reactions catalyzed by xylose dehydrogenase, xylonate dehydratase, 2-ketoacid decarboxylase, and alcohol dehydrogenase. We here aimed to improve the BT yield in S. cerevisiae by genetic engineering. First, the amount of the key intermediate 2-keto-3-deoxy-xylonate as described previously was successfully reduced in 41% by multiple integrations of Lactococcus lactis 2-ketoacid decarboxylase gene kdcA into the yeast genome. Since the heterologous BT synthetic pathway is independent of yeast native metabolism, this manipulation has led to NADH/NADPH imbalance and deficiency during BT production. Overexpression of the NADH kinase POS5Δ17 lacking the mitochondrial targeting sequence to relieve NADH/NADPH imbalance resulted in the BT titer of 2.2 g/L (31% molar yield). Feeding low concentrations of glucose and xylose to support the supply of NADH resulted in BT titer of 6.6 g/L with (57% molar yield). Collectively, improving the NADH/NADPH ratio and supply from glucose are essential for the construction of a xylose pathway, such as the BT synthetic pathway, independent of native yeast metabolism.
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Affiliation(s)
- Takahiro Yukawa
- Graduate School of Science, Technology and Innovation, Kobe University, Kobe, Japan
| | - Takahiro Bamba
- Graduate School of Science, Technology and Innovation, Kobe University, Kobe, Japan
| | - Gregory Guirimand
- Graduate School of Science, Technology and Innovation, Kobe University, Kobe, Japan.,Biomolécules et Biotechnologies Végétales, EA 2106, Département of Agronomie, productions animale et végétale et agro-alimentaire, Université de Tours, Tours, France.,LE STUDIUM, Loire Valley Institute for Advanced Studies, Orléans, France
| | - Mami Matsuda
- Graduate School of Science, Technology and Innovation, Kobe University, Kobe, Japan.,Engineering Biology Research Center, Kobe University, Kobe, Japan
| | - Tomohisa Hasunuma
- Graduate School of Science, Technology and Innovation, Kobe University, Kobe, Japan.,Engineering Biology Research Center, Kobe University, Kobe, Japan
| | - Akihiko Kondo
- Graduate School of Science, Technology and Innovation, Kobe University, Kobe, Japan.,Engineering Biology Research Center, Kobe University, Kobe, Japan.,Biomass Engineering Program, RIKEN, Yokohama, Kanagawa, Japan
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9
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Sun H, Yang J, Lin X, Li C, He Y, Cai Z, Zhang G, Song H. De Novo High-Titer Production of Delta-Tocotrienol in Recombinant Saccharomyces cerevisiae. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:7710-7717. [PMID: 32580548 DOI: 10.1021/acs.jafc.0c00294] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Delta-tocotrienol as a vitamin E isomer has received much attention because of its diverse biomedical applications. Microbial biosynthesis of delta-tocotrienol is a promising strategy for its economic and environmental advantages. Here, we accomplished complete biosynthesis of delta-tocotrienol in Saccharomyces cerevisiae from glucose. We first constructed and incorporated a heterologous pathway into the genome of S. cerevisiae by incorporating the genes hpd (from Pseudomonas putida KT2440), hpt (from Synechocystis sp. PCC 6803), and vte1 (from Arabidopsis thaliana) for the biosynthesis of delta-tocotrienol. We further enhanced the biosynthesis of the precursor geranylgeranyl diphosphate by overexpressing the thmg1 and ggppssa (from Sulfolobus acidocaldarius) genes, leading to a production titer of delta-tocotrienol of 1.39 ± 0.01 mg/L. Finally, we optimized the fermentation medium using the response surface methodology, enabling a high-titer production of delta-tocotrienol (3.56 ± 0.25 mg/L), ∼2.6-fold of that of the initial culture medium. Fed-batch fermentation in a 2 L fermenter was further used to enhance the production titer of delta-tocotrienol (4.10 ± 0.10 mg/L). To the best of our knowledge, this is the first report on the de novo biosynthesis of delta-tocotrienol in S. cerevisiae, and the highest titer obtained for microbial production of delta-tocotrienol.
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Affiliation(s)
- Hong Sun
- Frontier Science Center for Synthetic Biology, Key Laboratory of Systems Bioengineering (MOE), Collaborative Innovation Centre of Chemical Science and Engineering (Tianjin), and School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, P. R. China
| | - Jingli Yang
- Frontier Science Center for Synthetic Biology, Key Laboratory of Systems Bioengineering (MOE), Collaborative Innovation Centre of Chemical Science and Engineering (Tianjin), and School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, P. R. China
| | - Xue Lin
- College of Food Science and Technology, Hainan University, Haikou 570228, P. R. China
| | - Congfa Li
- College of Food Science and Technology, Hainan University, Haikou 570228, P. R. China
| | - Yongjin He
- Chifeng Pharmaceutical Company Limited, Chifeng, Inner Mongolia 024000, P. R. China
| | - Zhigang Cai
- Chifeng Pharmaceutical Company Limited, Chifeng, Inner Mongolia 024000, P. R. China
| | - Guoyin Zhang
- Chifeng Pharmaceutical Company Limited, Chifeng, Inner Mongolia 024000, P. R. China
| | - Hao Song
- Frontier Science Center for Synthetic Biology, Key Laboratory of Systems Bioengineering (MOE), Collaborative Innovation Centre of Chemical Science and Engineering (Tianjin), and School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, P. R. China
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10
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Cripwell RA, Favaro L, Viljoen-Bloom M, van Zyl WH. Consolidated bioprocessing of raw starch to ethanol by Saccharomyces cerevisiae: Achievements and challenges. Biotechnol Adv 2020; 42:107579. [PMID: 32593775 DOI: 10.1016/j.biotechadv.2020.107579] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 06/05/2020] [Accepted: 06/14/2020] [Indexed: 12/30/2022]
Abstract
Recent advances in amylolytic strain engineering for starch-to-ethanol conversion have provided a platform for the development of raw starch consolidated bioprocessing (CBP) technologies. Several proof-of-concept studies identified improved enzyme combinations, alternative feedstocks and novel host strains for evaluation and application under fermentation conditions. However, further research efforts are required before this technology can be scaled up to an industrial level. In this review, different CBP approaches are defined and discussed, also highlighting the role of auxiliary enzymes for a supplemented CBP process. Various achievements in the development of amylolytic Saccharomyces cerevisiae strains for CBP of raw starch and the remaining challenges that need to be tackled/pursued to bring yeast raw starch CBP to industrial realization, are described. Looking towards the future, it provides potential solutions to develop more cost-effective processes that include cheaper substrates, integration of the 1G and 2G economies and implementing a biorefinery concept where high-value products are also derived from starchy substrates.
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Affiliation(s)
- Rosemary A Cripwell
- Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
| | - Lorenzo Favaro
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Università di Padova, Agripolis, Viale dell'Università 16, 35020, Legnaro, Padova, Italy
| | - Marinda Viljoen-Bloom
- Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
| | - Willem H van Zyl
- Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa.
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11
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Myburgh MW, Cripwell RA, Favaro L, van Zyl WH. Application of industrial amylolytic yeast strains for the production of bioethanol from broken rice. BIORESOURCE TECHNOLOGY 2019; 294:122222. [PMID: 31683453 DOI: 10.1016/j.biortech.2019.122222] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 09/27/2019] [Accepted: 09/28/2019] [Indexed: 06/10/2023]
Abstract
Amylolytic Saccharomyces cerevisiae derivatives of Ethanol Red™ Version 1 (ER T12) and M2n (M2n T1) were assessed through enzyme assays, hydrolysis trials, electron microscopy and fermentation studies using broken rice. The heterologous enzymes hydrolysed broken rice at a similar rate compared to commercial granular starch-hydrolysing enzyme cocktail. During the fermentation of 20% dw/v broken rice, the amylolytic strains converted rice starch to ethanol in a single step and yielded high ethanol titers. The best-performing strain (ER T12) produced 93% of the theoretical ethanol yield after 96 h of consolidated bioprocessing (CBP) fermentation at 32 °C. Furthermore, the addition of commercial enzyme cocktail (10% of the recommended dosage) in combination with ER T12 did not significantly improve the maximum ethanol concentration, confirming the superior ability of ER T12 to hydrolyse raw starch. The ER T12 strain was therefore identified as an ideal candidate for the CBP of starch-rich waste streams.
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Affiliation(s)
- Marthinus W Myburgh
- Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
| | - Rosemary A Cripwell
- Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
| | - Lorenzo Favaro
- Department of Agronomy Food Natural Resources Animals and Environment (DAFNAE), Padova University, Agripolis, Viale dell'Università 16, 35020 Legnaro, Padova, Italy.
| | - Willem H van Zyl
- Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
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12
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Ellis GA, Klein WP, Lasarte-Aragonés G, Thakur M, Walper SA, Medintz IL. Artificial Multienzyme Scaffolds: Pursuing in Vitro Substrate Channeling with an Overview of Current Progress. ACS Catal 2019. [DOI: 10.1021/acscatal.9b02413] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Gregory A. Ellis
- Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
| | - William P. Klein
- Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
- National Research Council, Washington, D.C. 20001, United States
| | - Guillermo Lasarte-Aragonés
- Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
- College of Science, George Mason University, Fairfax, Virginia 22030, United States
| | - Meghna Thakur
- Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
- College of Science, George Mason University, Fairfax, Virginia 22030, United States
| | - Scott A. Walper
- Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
| | - Igor L. Medintz
- Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
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13
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Bamba T, Yukawa T, Guirimand G, Inokuma K, Sasaki K, Hasunuma T, Kondo A. Production of 1,2,4-butanetriol from xylose by Saccharomyces cerevisiae through Fe metabolic engineering. Metab Eng 2019; 56:17-27. [PMID: 31434008 DOI: 10.1016/j.ymben.2019.08.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 07/24/2019] [Accepted: 08/17/2019] [Indexed: 11/29/2022]
Abstract
1,2,4-Butanetriol can be used to produce energetic plasticizer as well as several pharmaceutical compounds. Although Saccharomyces cerevisiae has some attractive characters such as high robustness for industrial production of useful chemicals by fermentation, 1,2,4-butanetriol production by S. cerevisiae has not been reported. 1,2,4-butanteriotl is produced by an oxidative xylose metabolic pathway completely different from the xylose reductase-xylitol dehydrogenase and the xylose isomerase pathways conventionally used for xylose assimilation in S. cerevisiae. In the present study, S. cerevisiae was engineered to produce 1,2,4-butanetriol by overexpression of xylose dehydrogenase (XylB), xylonate dehydratase (XylD), and 2-ketoacid decarboxylase. Further improvement of the recombinant strain was performed by the screening of optimal 2-ketoacid decarboxylase suitable for 1,2,4-butanetriol production and the enhancement of Fe uptake ability to improve the XylD enzymatic activity. Eventually, 1.7 g/L of 1,2,4-butanetriol was produced from 10 g/L xylose with a molar yield of 24.5%. Furthermore, 1.1 g/L of 1,2,4-butanetriol was successfully produced by direct fermentation of rice straw hydrolysate.
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Affiliation(s)
- Takahiro Bamba
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
| | - Takahiro Yukawa
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
| | - Gregory Guirimand
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan; Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
| | - Kentaro Inokuma
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
| | - Kengo Sasaki
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan; Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
| | - Tomohisa Hasunuma
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan; Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
| | - Akihiko Kondo
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan; Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan; Biomass Engineering Program, RIKEN, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan.
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14
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Bioethanol production from microalgae polysaccharides. Folia Microbiol (Praha) 2019; 64:627-644. [PMID: 31352666 DOI: 10.1007/s12223-019-00732-0] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 07/15/2019] [Indexed: 12/19/2022]
Abstract
The worldwide growing demand for energy permanently increases the pressure on industrial and scientific community to introduce new alternative biofuels on the global energy market. Besides the leading role of biodiesel and biogas, bioethanol receives more and more attention as first- and second-generation biofuel in the sustainable energy industry. Lately, microalgae (green algae and cyanobacteria) biomass has also remarkable potential as a feedstock for the third-generation biofuel production due to their high lipid and carbohydrate content. The third-generation bioethanol production technology can be divided into three major processing ways: (i) fermentation of pre-treated microalgae biomass, (ii) dark fermentation of reserved carbohydrates and (iii) direct "photo-fermentation" from carbon dioxide to bioethanol using light energy. All three technologies provide possible solutions, but from a practical point of view, traditional fermentation technology from microalgae biomass receives currently the most attention. This study mainly focusses on the latest advances in traditional fermentation processes including the steps of enhanced carbohydrate accumulation, biomass pre-treatment, starch and glycogen downstream processing and various fermentation approaches.
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15
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Global Warming Potential of Biomass-to-Ethanol: Review and Sensitivity Analysis through a Case Study. ENERGIES 2019. [DOI: 10.3390/en12132535] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In Europe, ethanol is blended with gasoline fuel in 5 or 10% volume (E5 or E10). In USA the blend is 15% in volume (E15) and there are also pumps that provide E85. In Brazil, the conventional gasoline is E27 and there are pumps that offer E100, due to the growing market of flex fuel vehicles. Bioethanol production is usually by means of biological conversion of several biomass feedstocks (first generation sugar cane in Brazil, corn in the USA, sugar beet in Europe, or second-generation bagasse of sugarcane or lignocellulosic materials from crop wastes). The environmental sustainability of the bioethanol is usually measured by the global warming potential metric (GWP in CO2eq), 100 years time horizon. Reviewed values could range from 0.31 to 5.55 gCO2eq/LETOH. A biomass-to-ethanol industrial scenario was used to evaluate the impact of methodological choices on CO2eq: conventional versus dynamic Life Cycle Assessment; different impact assessment methods (TRACI, IPCC, ILCD, IMPACT, EDIP, and CML); electricity mix of the geographical region/country for different factory locations; differences in CO2eq factor for CH4 and N2O due to updates in Intergovernmental Panel on Climate Change (IPCC) reports (5 reports so far), different factory operational lifetimes and future improved productivities. Results showed that the electricity mix (factory location) and land use are the factors that have the greatest effect (up to 800% deviation). The use of the CO2 equivalency factors stated in different IPCC reports has the least influence (less than 3%). The consideration of the biogenic emissions (uptake at agricultural stage and release at the fermentation stage) and different allocation methods is also influential, and each can make values vary by 250%.
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Yamada R, Yamauchi A, Ando Y, Kumata Y, Ogino H. Modulation of gene expression by cocktail δ-integration to improve carotenoid production in Saccharomyces cerevisiae. BIORESOURCE TECHNOLOGY 2018; 268:616-621. [PMID: 30138874 DOI: 10.1016/j.biortech.2018.08.044] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 08/12/2018] [Accepted: 08/13/2018] [Indexed: 06/08/2023]
Abstract
Carotenoids, including β-carotene, are commercially valuable compounds, and their production by engineered Saccharomyces cerevisiae is a promising strategy for their industrial production. Here, to improve β-carotene productivity in engineered S. cerevisiae, a cocktail δ-integration strategy, which involves simultaneous integration of various multi-copy genes, followed by selection of desirable transformants, was applied for modulation of β-carotene production-related genes expression. The engineered strain, YPH499/Mo3Crt79, was constructed by three repeated rounds of cocktail δ-integration using CrtE, CrtYB, and CrtI derived from the yeast, Xanthophyllomyces dendrorhous. The recombinant strain produced 7.3 mg/L of carotenoids in 48 h and 52.3 mg/L of β-carotene in 96 h, which were greater values than those achieved by CrtE, CrtYB, and CrtI co-overexpressing strains. Therefore, repeated cocktail δ-integration was effective in improving carotenoid productivity in S. cerevisiae and could be a promising technique for constructing metabolically engineered S. cerevisiae capable of producing bio-based chemicals.
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Affiliation(s)
- Ryosuke Yamada
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
| | - Azusa Yamauchi
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Yorichika Ando
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Yuki Kumata
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Hiroyasu Ogino
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
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17
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Sasaki Y, Mitsui R, Yamada R, Ogino H. Secretory overexpression of the endoglucanase by Saccharomyces cerevisiae via CRISPR-δ-integration and multiple promoter shuffling. Enzyme Microb Technol 2018; 121:17-22. [PMID: 30554640 DOI: 10.1016/j.enzmictec.2018.10.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 10/19/2018] [Accepted: 10/29/2018] [Indexed: 12/21/2022]
Abstract
Various recombinant proteins can be produced by the yeast Saccharomyces cerevisiae cell factories; therefore, efficient recombinant protein production techniques are desirable. In this study, to establish an efficient recombinant protein production technique in S. cerevisiae, the secretory production of recombinant protein endoglucanase II (TrEG) was tested. We developed 2 novel methods for TrEG production via clustered regularly interspaced short palindromic repeat (CRISPR) -δ-integration as well as multiple promoter shuffling, which involved the pre-breakdown of the δ-sequence by the CRISPR system and subsequent δ-integration as well as the conjugation of TrEG with various promoters and subsequent δ-integration, respectively. Moreover, simultaneous use of the CRISPR-δ-integration and multiple promoter shuffling methods was also examined. The CRISPR-δ-integration method was effective for improvement of the integrated TrEG copy number and its activity, and the multiple promoter shuffling method was also beneficial for enhancing the transcriptional level of TrEG and its activity. Furthermore, simultaneous use of CRISPR-δ-integration and multiple promoter shuffling methods was the most useful. The carboxymethyl cellulase activity of the TrEG expressing transformant YPH499/24CP constructed by the method reached 559 U/L, and it was 17.3-fold higher than that of the transformant constructed by the conventional YEp type vector. Overall, the simultaneous use of CRISPR-δ-integration and multiple promoter shuffling can be useful and easily applied for recombinant protein production.
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Affiliation(s)
- Yuka Sasaki
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan
| | - Ryosuke Mitsui
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan
| | - Ryosuke Yamada
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan.
| | - Hiroyasu Ogino
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan
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18
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The Role of Yeast-Surface-Display Techniques in Creating Biocatalysts for Consolidated BioProcessing. Catalysts 2018. [DOI: 10.3390/catal8030094] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Climate change is directly linked to the rapid depletion of our non-renewable fossil resources and has posed concerns on sustainability. Thus, imploring the need for us to shift from our fossil based economy to a sustainable bioeconomy centered on biomass utilization. The efficient bioconversion of lignocellulosic biomass (an ideal feedstock) to a platform chemical, such as bioethanol, can be achieved via the consolidated bioprocessing technology, termed yeast surface engineering, to produce yeasts that are capable of this feat. This approach has various strategies that involve the display of enzymes on the surface of yeast to degrade the lignocellulosic biomass, then metabolically convert the degraded sugars directly into ethanol, thus elevating the status of yeast from an immobilization material to a whole-cell biocatalyst. The performance of the engineered strains developed from these strategies are presented, visualized, and compared in this article to highlight the role of this technology in moving forward to our quest against climate change. Furthermore, the qualitative assessment synthesized in this work can serve as a reference material on addressing the areas of improvement of the field and on assessing the capability and potential of the different yeast surface display strategies on the efficient degradation, utilization, and ethanol production from lignocellulosic biomass.
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19
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Yamada R, Wakita K, Mitsui R, Nishikawa R, Ogino H. Efficient production of 2,3-butanediol by recombinant Saccharomyces cerevisiae through modulation of gene expression by cocktail δ-integration. BIORESOURCE TECHNOLOGY 2017; 245:1558-1566. [PMID: 28522198 DOI: 10.1016/j.biortech.2017.05.034] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 05/05/2017] [Accepted: 05/06/2017] [Indexed: 06/07/2023]
Abstract
In this study, the expression of 4 genes encoding α-acetolactate synthase, α-acetolactate decarboxylase, 2,3-butanediol dehydrogenase, and NADH oxidase was modulated using a previously developed cocktail δ-integration strategy. The resultant strain, YPH499/dPdAdG/BD6-10, was used in a fed-batch cultivation for the production of 2,3-butanediol. The concentration, production rate, and yield obtained were 80.0g/L, 4.00g/L/h, and 41.7%, respectively. The production rate and yield of the compound obtained are higher for this strain compared to reports published for Saccharomyces cerevisiae so far. The cocktail δ-integration strategy allows for modulation of multiple gene expression, without the exact knowledge of rate-limiting steps, and therefore, could be used as a promising strategy for the production of bio-based chemicals in recombinant S. cerevisiae.
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Affiliation(s)
- Ryosuke Yamada
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
| | - Kazuki Wakita
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
| | - Ryosuke Mitsui
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
| | - Riru Nishikawa
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
| | - Hiroyasu Ogino
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
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20
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Yamada R, Wakita K, Mitsui R, Ogino H. Enhanced d
-lactic acid production by recombinant Saccharomyces cerevisiae
following optimization of the global metabolic pathway. Biotechnol Bioeng 2017; 114:2075-2084. [DOI: 10.1002/bit.26330] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 04/14/2017] [Accepted: 04/30/2017] [Indexed: 11/07/2022]
Affiliation(s)
- Ryosuke Yamada
- Department of Chemical Engineering; Osaka Prefecture University; 1-1 Gakuen-cho, Naka-ku Sakai Osaka 599-8531 Japan
| | - Kazuki Wakita
- Department of Chemical Engineering; Osaka Prefecture University; 1-1 Gakuen-cho, Naka-ku Sakai Osaka 599-8531 Japan
| | - Ryosuke Mitsui
- Department of Chemical Engineering; Osaka Prefecture University; 1-1 Gakuen-cho, Naka-ku Sakai Osaka 599-8531 Japan
| | - Hiroyasu Ogino
- Department of Chemical Engineering; Osaka Prefecture University; 1-1 Gakuen-cho, Naka-ku Sakai Osaka 599-8531 Japan
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Yamada R, Wakita K, Ogino H. Global Metabolic Engineering of Glycolytic Pathway via Multicopy Integration in Saccharomyces cerevisiae. ACS Synth Biol 2017; 6:659-666. [PMID: 28080037 DOI: 10.1021/acssynbio.6b00281] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The use of renewable feedstocks for producing biofuels and biobased chemicals by engineering metabolic pathways of yeast Saccharomyces cerevisiae has recently become an attractive option. Many researchers attempted to increase glucose consumption rate by overexpressing some glycolytic enzymes because most target biobased chemicals are derived through glycolysis. However, these attempts have met with little success. In this study, to create a S. cerevisiae strain with high glucose consumption rate, we used multicopy integration to develop a global metabolic engineering strategy. Among approximately 350 metabolically engineered strains, YPH499/dPdA3-34 exhibited the highest glucose consumption rate. This strain showed 1.3-fold higher cell growth rate and glucose consumption rate than the control strain. Real-time PCR analysis revealed that transcription levels of glycolysis-related genes such as HXK2, PFK1, PFK2, PYK2, PGI1, and PGK1 in YPH499/dPdA3-34 were increased. Our strategy is thus a promising approach to optimize global metabolic pathways in S. cerevisiae.
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Affiliation(s)
- Ryosuke Yamada
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Kazuki Wakita
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Hiroyasu Ogino
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
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22
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Zhang K, Fang YH, Gao KH, Sui Y, Zheng DQ, Wu XC. Effects of genome duplication on phenotypes and industrial applications of Saccharomyces cerevisiae strains. Appl Microbiol Biotechnol 2017; 101:5405-5414. [PMID: 28429058 DOI: 10.1007/s00253-017-8284-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 03/27/2017] [Accepted: 03/30/2017] [Indexed: 01/21/2023]
Abstract
Polyploidy is common in Saccharomyces cerevisiae strains, but the physiological and phenotypic effects of ploidy changes have not been fully clarified. Here, isogenic diploid, triploid, and tetraploid S. cerevisiae strains were constructed from a haploid strain, CEN.PK2-1C. Stress tolerance and ethanol fermentation performance of the four euploid strains were compared. Each euploid strain had strengths and weaknesses in tolerance to certain stressors, and no single strain was tolerant of all stressors. The diploid had higher ethanol production than the other strains in normal fermentation medium, while the triploid strain showed the fastest fermentation rate in the presence of inhibitors found in lignocellulosic hydrolysate. Physiological determination revealed diverse physiological attributes, such as trehalose, ergosterol, glutathione, and anti-oxidative enzymes among the strains. Our analyses suggest that both ploidy parity and number of chromosome sets contribute to changes in physiological status. Using qRT-PCR, different expression patterns of genes involved in the regulation of cell morphology and the biosynthesis of key physiological attributes among strains were determined. Our data provide novel insights into the multiple effects of genome duplication on yeast cells and are a useful reference for breeding excellent strains used in specific industrial applications.
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Affiliation(s)
- Ke Zhang
- College of Life Science, Zhejiang University, Hangzhou, Zhejiang Province, 310058, China.,Ocean College, Zhejiang University, Zhoushan, Zhejiang Province, 316021, China
| | - Ya-Hong Fang
- College of Life Science, Zhejiang University, Hangzhou, Zhejiang Province, 310058, China
| | - Ke-Hui Gao
- College of Life Science, Zhejiang University, Hangzhou, Zhejiang Province, 310058, China
| | - Yang Sui
- Ocean College, Zhejiang University, Zhoushan, Zhejiang Province, 316021, China
| | - Dao-Qiong Zheng
- Ocean College, Zhejiang University, Zhoushan, Zhejiang Province, 316021, China.
| | - Xue-Chang Wu
- College of Life Science, Zhejiang University, Hangzhou, Zhejiang Province, 310058, China.
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23
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Hasunuma T, Kondo A. Production of Fuels and Chemicals from Biomass by Integrated Bioprocesses. Ind Biotechnol (New Rochelle N Y) 2016. [DOI: 10.1002/9783527807833.ch5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Tomohisa Hasunuma
- Kobe University; Graduate School of Science, Technology and Innovation; 1-1 Rokkodai Nada Kobe 657-8501 Japan
| | - Akihiko Kondo
- RIKEN; Biomass Engineering Program; 1-7-22 Suehiro-cho, Tsurumi Yokohama 230-0045 Japan
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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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25
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Huang M, Gao Y, Zhou X, Zhang Y, Cai M. Regulating unfolded protein response activator HAC1p for production of thermostable raw-starch hydrolyzing α-amylase in Pichia pastoris. Bioprocess Biosyst Eng 2016; 40:341-350. [DOI: 10.1007/s00449-016-1701-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Accepted: 10/21/2016] [Indexed: 11/27/2022]
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Wang J, Ma Y, Zhang K, Yang H, Liu C, Zou S, Hong J, Zhang M. Mating type and ploidy effect on the β-glucosidase activity and ethanol-producing performance of Saccharomyces cerevisiae with multiple δ-integrated bgl 1 gene. J Biotechnol 2016; 231:24-31. [DOI: 10.1016/j.jbiotec.2016.05.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 05/20/2016] [Accepted: 05/20/2016] [Indexed: 11/15/2022]
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Ethanol production from acid- and alkali-pretreated corncob by endoglucanase and β-glucosidase co-expressing Saccharomyces cerevisiae subject to the expression of heterologous genes and nutrition added. World J Microbiol Biotechnol 2016; 32:86. [DOI: 10.1007/s11274-016-2043-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 03/01/2016] [Indexed: 10/22/2022]
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Bamba T, Hasunuma T, Kondo A. Disruption of PHO13 improves ethanol production via the xylose isomerase pathway. AMB Express 2016; 6:4. [PMID: 26769491 PMCID: PMC4713403 DOI: 10.1186/s13568-015-0175-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 12/11/2015] [Indexed: 01/08/2023] Open
Abstract
Xylose is the second most abundant sugar in lignocellulosic materials and can be converted to ethanol by recombinant Saccharomyces cerevisiae yeast strains expressing heterologous genes involved in xylose assimilation pathways. Recent research demonstrated that disruption of the alkaline phosphatase gene, PHO13, enhances ethanol production from xylose by a strain expressing the xylose reductase (XR) and xylitol dehydrogenase (XDH) genes; however, the yield of ethanol is poor. In this study, PHO13 was disrupted in a recombinant strain harboring multiple copies of the xylose isomerase (XI) gene derived from Orpinomyces sp., coupled with overexpression of the endogenous xylulokinase (XK) gene and disruption of GRE3, which encodes aldose reductase. The resulting YΔGP/XK/XI strain consumed 2.08 g/L/h of xylose and produced 0.88 g/L/h of volumetric ethanol, for an 86.8 % theoretical ethanol yield, and only YΔGP/XK/XI demonstrated increase in cell concentration. Transcriptome analysis indicated that expression of genes involved in the pentose phosphate pathway (GND1, SOL3, TAL1, RKI1, and TKL1) and TCA cycle and respiratory chain (NDE1, ACO1, ACO2, SDH2, IDH1, IDH2, ATP7, ATP19, SDH4, SDH3, CMC2, and ATP15) was upregulated in the YΔGP/XK/XI strain. And the expression levels of 125 cell cycle genes were changed by deletion of PHO13.
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Favaro L, Viktor MJ, Rose SH, Viljoen-Bloom M, van Zyl WH, Basaglia M, Cagnin L, Casella S. Consolidated bioprocessing of starchy substrates into ethanol by industrial Saccharomyces cerevisiae strains secreting fungal amylases. Biotechnol Bioeng 2015; 112:1751-60. [PMID: 25786804 DOI: 10.1002/bit.25591] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 02/03/2015] [Accepted: 03/09/2015] [Indexed: 01/16/2023]
Abstract
The development of a yeast strain that converts raw starch to ethanol in one step (called Consolidated Bioprocessing, CBP) could significantly reduce the commercial costs of starch-based bioethanol. An efficient amylolytic Saccharomyces cerevisiae strain suitable for industrial bioethanol production was developed in this study. Codon-optimized variants of the Thermomyces lanuginosus glucoamylase (TLG1) and Saccharomycopsis fibuligera α-amylase (SFA1) genes were δ-integrated into two S. cerevisiae yeast with promising industrial traits, i.e., strains M2n and MEL2. The recombinant M2n[TLG1-SFA1] and MEL2[TLG1-SFA1] yeast displayed high enzyme activities on soluble and raw starch (up to 8118 and 4461 nkat/g dry cell weight, respectively) and produced about 64 g/L ethanol from 200 g/L raw corn starch in a bioreactor, corresponding to 55% of the theoretical maximum ethanol yield (g of ethanol/g of available glucose equivalent). Their starch-to-ethanol conversion efficiencies were even higher on natural sorghum and triticale substrates (62 and 73% of the theoretical yield, respectively). This is the first report of direct ethanol production from natural starchy substrates (without any pre-treatment or commercial enzyme addition) using industrial yeast strains co-secreting both a glucoamylase and α-amylase.
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Affiliation(s)
- Lorenzo Favaro
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Università di Padova, Agripolis, Viale dell'Università 16, 35020, Legnaro (PD), Italy
| | - Marko J Viktor
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | - Shaunita H Rose
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | | | - Willem H van Zyl
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | - Marina Basaglia
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Università di Padova, Agripolis, Viale dell'Università 16, 35020, Legnaro (PD), Italy.
| | - Lorenzo Cagnin
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Università di Padova, Agripolis, Viale dell'Università 16, 35020, Legnaro (PD), Italy
| | - Sergio Casella
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Università di Padova, Agripolis, Viale dell'Università 16, 35020, Legnaro (PD), Italy
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Noda S, Shirai T, Mochida K, Matsuda F, Oyama S, Okamoto M, Kondo A. Evaluation of Brachypodium distachyon L-Tyrosine Decarboxylase Using L-Tyrosine Over-Producing Saccharomyces cerevisiae. PLoS One 2015; 10:e0125488. [PMID: 25996877 PMCID: PMC4440718 DOI: 10.1371/journal.pone.0125488] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 03/14/2015] [Indexed: 11/18/2022] Open
Abstract
To demonstrate that herbaceous biomass is a versatile gene resource, we focused on the model plant Brachypodium distachyon, and screened the B. distachyon for homologs of tyrosine decarboxylase (TDC), which is involved in the modification of aromatic compounds. A total of 5 candidate genes were identified in cDNA libraries of B. distachyon and were introduced into Saccharomyces cerevisiae to evaluate TDC expression and tyramine production. It is suggested that two TDCs encoded in the transcripts Bradi2g51120.1 and Bradi2g51170.1 have L-tyrosine decarboxylation activity. Bradi2g51170.1 was introduced into the L-tyrosine over-producing strain of S. cerevisiae that was constructed by the introduction of mutant genes that promote deregulated feedback inhibition. The amount of tyramine produced by the resulting transformant was 6.6-fold higher (approximately 200 mg/L) than the control strain, indicating that B. distachyon TDC effectively converts L-tyrosine to tyramine. Our results suggest that B. distachyon possesses enzymes that are capable of modifying aromatic residues, and that S. cerevisiae is a suitable host for the production of L-tyrosine derivatives.
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Affiliation(s)
- Shuhei Noda
- Biomass Engineering Program, RIKEN, Yokohama, Kanagawa, Japan
| | - Tomokazu Shirai
- Biomass Engineering Program, RIKEN, Yokohama, Kanagawa, Japan
| | - Keiichi Mochida
- Biomass Engineering Program, RIKEN, Yokohama, Kanagawa, Japan
| | - Fumio Matsuda
- Biomass Engineering Program, RIKEN, Yokohama, Kanagawa, Japan; Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, Suita, Osaka, Japan
| | - Sachiko Oyama
- Biomass Engineering Program, RIKEN, Yokohama, Kanagawa, Japan
| | - Mami Okamoto
- Biomass Engineering Program, RIKEN, Yokohama, Kanagawa, Japan
| | - Akihiko Kondo
- Biomass Engineering Program, RIKEN, Yokohama, Kanagawa, Japan; Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, Kobe, Japan
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Efficient co-displaying and artificial ratio control of α-amylase and glucoamylase on the yeast cell surface by using combinations of different anchoring domains. Appl Microbiol Biotechnol 2014; 99:1655-63. [PMID: 25432675 DOI: 10.1007/s00253-014-6250-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 11/16/2014] [Accepted: 11/18/2014] [Indexed: 10/24/2022]
Abstract
Recombinant yeast strains that display heterologous amylolytic enzymes on their cell surface via the glycosylphosphatidylinositol (GPI)-anchoring system are considered as promising biocatalysts for direct ethanol production from starchy materials. For the effective hydrolysis of these materials, the ratio optimization of multienzyme activity displayed on the cell surface is important. In this study, we have presented a ratio control system of multienzymes displayed on the yeast cell surface by using different GPI-anchoring domains. The novel gene cassettes for the cell-surface display of Streptococcus bovis α-amylase and Rhizopus oryzae glucoamylase were constructed using the Saccharomyces cerevisiae SED1 promoter and two different GPI-anchoring regions derived from Saccharomyces cerevisiae SED1 or SAG1. These gene cassettes were integrated into the Saccharomyces cerevisiae genome in different combinations. Then, the cell-surface α-amylase and glucoamylase activities and ethanol productivity of these recombinant strains were evaluated. The combinations of the gene cassettes of these enzymes affected the ratio of cell-surface α-amylase and glucoamylase activities and ethanol productivity of the recombinant strains. The highest ethanol productivity from raw starch was achieved by the strain harboring one α-amylase gene cassette carrying the SED1-anchoring region and two glucoamylase gene cassettes carrying the SED1-anchoring region (BY-AASS/GASS/GASS). This strain yielded 22.5 ± 0.6 g/L of ethanol from 100 g/L of raw starch in 120 h of fermentation.
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32
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Hong J, Yang H, Zhang K, Liu C, Zou S, Zhang M. Development of a cellulolytic Saccharomyces cerevisiae strain with enhanced cellobiohydrolase activity. World J Microbiol Biotechnol 2014; 30:2985-93. [PMID: 25164958 DOI: 10.1007/s11274-014-1726-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 08/20/2014] [Indexed: 11/27/2022]
Abstract
Consolidated bioprocessing (CBP) is a promising technology for lignocellulosic ethanol production, and the key is the engineering of a microorganism that can efficiently utilize cellulose. Development of Saccharomyces cerevisiae for CBP requires high level expression of cellulases, particularly cellobiohydrolases (CBH). In this study, to construct a CBP-enabling yeast with enhanced CBH activity, three cassettes containing constitutively expressed CBH-encoding genes (cbh1 from Aspergillus aculeatus, cbh1 and cbh2 from Trichoderma reesei) were constructed. T. reesei eg2, A. aculeatus bgl1, and the three CBH-encoding genes were then sequentially integrated into the S. cerevisiae W303-1A chromosome via δ-sequence-mediated integration. The resultant strains W1, W2, and W3, expressing uni-, bi-, and trifunctional cellulases, respectively, exhibited corresponding cellulase activities. Furthermore, both the activities and glucose producing activity ascended. The growth test on cellulose containing plates indicated that CBH was a necessary component for successful utilization of crystalline cellulose. The three recombinant strains and the control strains W303-1A and AADY were evaluated in acid- and alkali-pretreated corncob containing media with 5 FPU exogenous cellulase/g biomass loading. The highest ethanol titer (g/l) within 7 days was 5.92 ± 0.51, 18.60 ± 0.81, 28.20 ± 0.84, 1.40 ± 0.12, and 2.12 ± 0.35, respectively. Compared with the control strains, W3 efficiently fermented pretreated corncob to ethanol. To our knowledge, this is the first study aimed at creating cellulolytic yeast with enhanced CBH activity by integrating three types of CBH-encoding gene with a strong constitutive promoter Ptpi.
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Affiliation(s)
- Jiefang Hong
- Tianjin R&D Center for Petrochemical Technology, Tianjin University, Tianjin, 300072, China
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Görgens JF, Bressler DC, van Rensburg E. EngineeringSaccharomyces cerevisiaefor direct conversion of raw, uncooked or granular starch to ethanol. Crit Rev Biotechnol 2014; 35:369-91. [DOI: 10.3109/07388551.2014.888048] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Wang R, Wang D, Gao X, Hong J. Direct fermentation of raw starch using aKluyveromyces marxianusstrain that expresses glucoamylase and Alpha-amylase to produce ethanol. Biotechnol Prog 2014; 30:338-47. [DOI: 10.1002/btpr.1877] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2013] [Revised: 01/26/2014] [Accepted: 01/26/2014] [Indexed: 11/09/2022]
Affiliation(s)
- Rongliang Wang
- School of Life Science, University of Science and Technology of China; Hefei Anhui 230026, P. R., China
- Hefei National Laboratory for Physical Science at the Microscale; Hefei Anhui 230026 P.R. China
| | - Dongmei Wang
- School of Life Science, University of Science and Technology of China; Hefei Anhui 230026, P. R., China
- Hefei National Laboratory for Physical Science at the Microscale; Hefei Anhui 230026 P.R. China
| | - Xiaolian Gao
- School of Life Science, University of Science and Technology of China; Hefei Anhui 230026, P. R. China
- Hefei National Laboratory for Physical Science at the Microscale; Hefei Anhui 230026 P.R. China
- Dept. of Biology and Biochemistry; University of Houston; Houston TX 77004-5001
| | - Jiong Hong
- School of Life Science; University of Science and Technology of China; Hefei Anhui 230026, P. R. China
- Hefei National Laboratory for Physical Science at the Microscale; Hefei Anhui 230026 P.R. China
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Viktor MJ, Rose SH, van Zyl WH, Viljoen-Bloom M. Raw starch conversion by Saccharomyces cerevisiae expressing Aspergillus tubingensis amylases. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:167. [PMID: 24286270 PMCID: PMC4176734 DOI: 10.1186/1754-6834-6-167] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 10/09/2013] [Indexed: 05/03/2023]
Abstract
BACKGROUND Starch is one of the most abundant organic polysaccharides available for the production of bio-ethanol as an alternative transport fuel. Cost-effective utilisation of starch requires consolidated bioprocessing (CBP) where a single microorganism can produce the enzymes required for hydrolysis of starch, and also convert the glucose monomers to ethanol. RESULTS The Aspergillus tubingensis T8.4 α-amylase (amyA) and glucoamylase (glaA) genes were cloned and expressed in the laboratory strain Saccharomyces cerevisiae Y294 and the semi-industrial strain, S. cerevisiae Mnuα1. The recombinant AmyA and GlaA displayed protein sizes of 110-150 kDa and 90 kDa, respectively, suggesting significant glycosylation in S. cerevisiae. The Mnuα1[AmyA-GlaA] and Y294[AmyA-GlaA] strains were able to utilise 20 g l-1 raw corn starch as sole carbohydrate source, with ethanol titers of 9.03 and 6.67 g l-1 (0.038 and 0.028 g l-1 h-1), respectively, after 10 days. With a substrate load of 200 g l-1 raw corn starch, Mnuα1[AmyA-GlaA] yielded 70.07 g l-1 ethanol (0.58 g l-1 h-1) after 120 h of fermentation, whereas Y294[AmyA-GlaA] was less efficient at 43.33 g l-1 ethanol (0.36 g l-1 h-1). CONCLUSIONS In a semi-industrial amylolytic S. cerevisiae strain expressing the A. tubingensis α-amylase and glucoamylase genes, 200 g l-1 raw starch was completely hydrolysed (saccharified) in 120 hours with 74% converted to released sugars plus fermentation products and the remainder presumably to biomass. The single-step conversion of raw starch represents significant progress towards the realisation of CBP without the need for any heat pretreatment. Furthermore, the amylases were produced and secreted by the host strain, thus circumventing the need for exogenous amylases.
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Affiliation(s)
- Marko J Viktor
- Department of Microbiology, Stellenbosch University, Private Bag ×1, Stellenbosch, Matieland 7602, South Africa
| | - Shaunita H Rose
- Department of Microbiology, Stellenbosch University, Private Bag ×1, Stellenbosch, Matieland 7602, South Africa
| | - Willem H van Zyl
- Department of Microbiology, Stellenbosch University, Private Bag ×1, Stellenbosch, Matieland 7602, South Africa
| | - Marinda Viljoen-Bloom
- Department of Microbiology, Stellenbosch University, Private Bag ×1, Stellenbosch, Matieland 7602, South Africa
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Dikicioglu D, Pir P, Oliver SG. Predicting complex phenotype-genotype interactions to enable yeast engineering: Saccharomyces cerevisiae as a model organism and a cell factory. Biotechnol J 2013; 8:1017-34. [PMID: 24031036 PMCID: PMC3910164 DOI: 10.1002/biot.201300138] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 07/15/2013] [Accepted: 08/07/2013] [Indexed: 11/08/2022]
Abstract
There is an increasing use of systems biology approaches in both "red" and "white" biotechnology in order to enable medical, medicinal, and industrial applications. The intricate links between genotype and phenotype may be explained through the use of the tools developed in systems biology, synthetic biology, and evolutionary engineering. Biomedical and biotechnological research are among the fields that could benefit most from the elucidation of this complex relationship. Researchers have studied fitness extensively to explain the phenotypic impacts of genetic variations. This elaborate network of dependencies and relationships so revealed are further complicated by the influence of environmental effects that present major challenges to our achieving an understanding of the cellular mechanisms leading to healthy or diseased phenotypes or optimized production yields. An improved comprehension of complex genotype-phenotype interactions and their accurate prediction should enable us to more effectively engineer yeast as a cell factory and to use it as a living model of human or pathogen cells in intelligent screens for new drugs. This review presents different methods and approaches undertaken toward improving our understanding and prediction of the growth phenotype of the yeast Saccharomyces cerevisiae as both a model and a production organism.
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Affiliation(s)
- Duygu Dikicioglu
- Cambridge Systems Biology Centre and Department of Biochemistry, University of Cambridge, CB2 1GA, Cambridge, UK
| | - Pınar Pir
- Babraham Institute, Babraham Research Campus, CB22 3AT, Cambridge, UK
| | - Stephen G Oliver
- Cambridge Systems Biology Centre and Department of Biochemistry, University of Cambridge, CB2 1GA, Cambridge, UK
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Nakatani Y, Yamada R, Ogino C, Kondo A. Synergetic effect of yeast cell-surface expression of cellulase and expansin-like protein on direct ethanol production from cellulose. Microb Cell Fact 2013; 12:66. [PMID: 23835302 PMCID: PMC3716962 DOI: 10.1186/1475-2859-12-66] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2013] [Accepted: 07/02/2013] [Indexed: 12/02/2022] Open
Abstract
Background Numerous studies have examined the direct fermentation of cellulosic materials by cellulase-expressing yeast; however, ethanol productivity in these systems has not yet reached an industrial level. Certain microorganisms, such as the cellulolytic fungus Trichoderma reesei, produce expansin-like proteins, which have a cellulose-loosening effect that may increase the breakdown of cellulose. Here, to improve the direct conversion of cellulose to ethanol, yeast Saccharomyces cerevisiae co-displaying cellulase and expansin-like protein on the cell surface were constructed and examined for direct ethanol fermentation performance. Results The cellulase and expansin-like protein co-expressing strain showed 246 mU/g-wet cell of phosphoric acid swollen cellulose (PASC) degradation activity, which corresponded to 2.9-fold higher activity than that of a cellulase-expressing strain. This result clearly demonstrated that yeast cell-surface expressed cellulase and expansin-like protein act synergistically to breakdown cellulose. In fermentation experiments examining direct ethanol production from PASC, the cellulase and expansin-like protein co-expressing strain produced 3.4 g/L ethanol after 96 h of fermentation, a concentration that was 1.4-fold higher than that achieved by the cellulase-expressing strain (2.5 g/L). Conclusions The PASC degradation and fermentation ability of an engineered yeast strain was markedly improved by co-expressing cellulase and expansin-like protein on the cell surface. To our knowledge, this is the first report to demonstrate the synergetic effect of co-expressing cellulase and expansin-like protein on a yeast cell surface, which may be a promising strategy for constructing direct ethanol fermenting yeast from cellulose.
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Yamada R, Nakatani Y, Ogino C, Kondo A. Efficient direct ethanol production from cellulose by cellulase- and cellodextrin transporter-co-expressing Saccharomyces cerevisiae. AMB Express 2013; 3:34. [PMID: 23800294 PMCID: PMC3699431 DOI: 10.1186/2191-0855-3-34] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 06/18/2013] [Indexed: 11/10/2022] Open
Abstract
Efficient degradation of cellulosic biomass requires the synergistic action of the cellulolytic enzymes endoglucanase, cellobiohydrolase, and β-glucosidase. Although there are many reports describing consolidation of hydrolysis and fermentation steps using recombinant Saccharomyces cerevisiae that express cellulolytic enzymes, the efficiency of cellulose degradation has not been sufficiently improved. Although the yeast S. cerevisiae cannot take up cellooligosaccharide, some fungi can take up and assimilate cellooligosaccharide through a cellodextrin transporter. In this study, a S. cerevisiae strain co-expressing genes for several cell surface display cellulases and the cellodextrin transporter was constructed for the purpose of improving the efficiency of direct ethanol fermentation from phosphoric acid swollen cellulose (PASC). The cellulase/cellodextrin transporter-coexpressing strain produced 1.7-fold more ethanol (4.3 g/L) from PASC during a 72-h fermentation than did a strain expressing cellulase only (2.5 g/L). Direct ethanol production from PASC by the recombinant S. cerevisiae strain was improved by co-expression of cellulase display and cellodextrin transporter genes. These results suggest that cellulase- and cellodextrin transporter-co-expressing S. cerevisiae could be a promising technology for efficient direct ethanol production from cellulose.
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Yamamoto K, Matsumoto T, Shimada S, Tanaka T, Kondo A. Starchy biomass-powered enzymatic biofuel cell based on amylases and glucose oxidase multi-immobilized bioanode. N Biotechnol 2013; 30:531-5. [DOI: 10.1016/j.nbt.2013.04.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 04/04/2013] [Accepted: 04/16/2013] [Indexed: 11/26/2022]
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40
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Matano Y, Hasunuma T, Kondo A. Cell recycle batch fermentation of high-solid lignocellulose using a recombinant cellulase-displaying yeast strain for high yield ethanol production in consolidated bioprocessing. BIORESOURCE TECHNOLOGY 2013; 135:403-9. [PMID: 22954707 DOI: 10.1016/j.biortech.2012.07.025] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Revised: 07/02/2012] [Accepted: 07/05/2012] [Indexed: 05/26/2023]
Abstract
The aim of this study is to develop a scheme of cell recycle batch fermentation (CRBF) of high-solid lignocellulosic materials. Two-phase separation consisting of rough removal of lignocellulosic residues by low-speed centrifugation and solid-liquid separation enabled effective collection of Saccharomyces cerevisiae cells with decreased lignin and ash. Five consecutive batch fermentation of 200 g/L rice straw hydrothermally pretreated led to an average ethanol titer of 34.5 g/L. Moreover, the display of cellulases on the recombinant yeast cell surface increased ethanol titer to 42.2 g/L. After, five-cycle fermentation, only 3.3 g/L sugar was retained in the fermentation medium, because cellulase displayed on the cell surface hydrolyzed cellulose that was not hydrolyzed by commercial cellulases or free secreted cellulases. Fermentation ability of the recombinant strain was successfully kept during a five-cycle repeated batch fermentation with 86.3% of theoretical yield based on starting biomass.
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Affiliation(s)
- Yuki Matano
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
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Yamada R, Hasunuma T, Kondo A. Endowing non-cellulolytic microorganisms with cellulolytic activity aiming for consolidated bioprocessing. Biotechnol Adv 2013; 31:754-63. [PMID: 23473971 DOI: 10.1016/j.biotechadv.2013.02.007] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 02/19/2013] [Accepted: 02/24/2013] [Indexed: 11/17/2022]
Abstract
With the exhaustion of fossil fuels and with the environmental issues they pose, utilization of abundant lignocellulosic biomass as a feedstock for biofuels and bio-based chemicals has recently become an attractive option. Lignocellulosic biomass is primarily composed of cellulose, hemicellulose, and lignin and has a very rigid and complex structure. It is accordingly much more expensive to process than starchy grains because of the need for extensive pretreatment and relatively large amounts of cellulases for efficient hydrolysis. Efficient and cost-effective methods for the production of biofuels and chemicals from lignocellulose are required. A consolidated bioprocess (CBP), which integrates all biological steps consisting of enzyme production, saccharification, and fermentation, is considered a promising strategy for reducing production costs. Establishing an efficient CBP using lignocellulosic biomass requires both lignocellulose degradation into glucose and efficient production of biofuels or chemicals from glucose. With this aim, many researchers are attempting to endow selected microorganisms with lignocellulose-assimilating ability. In this review, we focus on studies aimed at conferring lignocellulose-assimilating ability not only to yeast strains but also to bacterial strains by recombinant technology. Recent developments in improvement of enzyme productivity by microorganisms and in improvement of the specific activity of cellulase are emphasized.
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Affiliation(s)
- Ryosuke Yamada
- Organization of Advanced Science and Technology, Kobe University, 1-1 Rokkodaicho, Nada, Kobe 657-8501, Japan
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42
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Cell aggregations in yeasts and their applications. Appl Microbiol Biotechnol 2013; 97:2305-18. [PMID: 23397484 DOI: 10.1007/s00253-013-4735-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 01/19/2013] [Accepted: 01/21/2013] [Indexed: 12/23/2022]
Abstract
Yeasts can display four types of cellular aggregation: sexual, flocculation, biofilm formation, and filamentous growth. These cell aggregations arise, in some yeast strains, as a response to environmental or physiological changes. Sexual aggregation is part of the yeast mating process, representing the first step of meiotic recombination. The flocculation phenomenon is a calcium-dependent asexual reversible cellular aggregation that allows the yeast to withstand adverse conditions. Biofilm formation consists of multicellular aggregates that adhere to solid surfaces and are embedded in a protein matrix; this gives the yeast strain either the ability to colonize new environments or to survive harsh environmental conditions. Finally, the filamentous growth is the ability of some yeast strains to grow in filament forms. Filamentous growth can be attained by two different means, with the formation of either hyphae or pseudohyphae. Both hyphae and pseudohyphae arise when the yeast strain is under nutrient starvation conditions and they represent a means for the microbial strain to spread over a wide area to survey for food sources, without increasing its biomass. Additionally, this filamentous growth is also responsible for the invasive growth of some yeast.
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Adachi D, Koda R, Hama S, Yamada R, Nakashima K, Ogino C, Kondo A. An integrative process model of enzymatic biodiesel production through ethanol fermentation of brown rice followed by lipase-catalyzed ethanolysis in a water-containing system. Enzyme Microb Technol 2013; 52:118-22. [DOI: 10.1016/j.enzmictec.2012.11.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Revised: 11/14/2012] [Accepted: 11/15/2012] [Indexed: 10/27/2022]
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van Zyl WH, Bloom M, Viktor MJ. Engineering yeasts for raw starch conversion. Appl Microbiol Biotechnol 2012; 95:1377-88. [PMID: 22797599 DOI: 10.1007/s00253-012-4248-0] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 06/12/2012] [Accepted: 06/14/2012] [Indexed: 11/29/2022]
Abstract
Next to cellulose, starch is the most abundant hexose polymer in plants, an import food and feed source and a preferred substrate for the production of many industrial products. Efficient starch hydrolysis requires the activities of both α-1,4 and α-1,6-debranching hydrolases, such as endo-amylases, exo-amylases, debranching enzymes, and transferases. Although amylases are widely distributed in nature, only about 10 % of amylolytic enzymes are able to hydrolyse raw or unmodified starch, with a combination of α-amylases and glucoamylases as minimum requirement for the complete hydrolysis of raw starch. The cost-effective conversion of raw starch for the production of biofuels and other important by-products requires the expression of starch-hydrolysing enzymes in a fermenting yeast strain to achieve liquefaction, hydrolysis, and fermentation (Consolidated Bioprocessing, CBP) by a single organism. The status of engineering amylolytic activities into Saccharomyces cerevisiae as fermentative host is highlighted and progress as well as challenges towards a true CBP organism for raw starch is discussed. Conversion of raw starch by yeast secreting or displaying α-amylases and glucoamylases on their surface has been demonstrated, although not at high starch loading or conversion rates that will be economically viable on industrial scale. Once efficient conversion of raw starch can be demonstrated at commercial level, engineering of yeast to utilize alternative substrates and produce alternative chemicals as part of a sustainable biorefinery can be pursued to ensure the rightful place of starch converting yeasts in the envisaged bio-economy of the future.
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Affiliation(s)
- W H van Zyl
- Department of Microbiology, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa.
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Repeated fermentation from raw starch using Saccharomyces cerevisiae displaying both glucoamylase and α-amylase. Enzyme Microb Technol 2012; 50:343-7. [DOI: 10.1016/j.enzmictec.2012.03.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Revised: 03/12/2012] [Accepted: 03/12/2012] [Indexed: 11/21/2022]
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Kato H, Suyama H, Yamada R, Hasunuma T, Kondo A. Improvements in ethanol production from xylose by mating recombinant xylose-fermenting Saccharomyces cerevisiae strains. Appl Microbiol Biotechnol 2012; 94:1585-92. [PMID: 22406859 DOI: 10.1007/s00253-012-3914-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 01/13/2012] [Accepted: 01/19/2012] [Indexed: 11/30/2022]
Abstract
To improve the ability of recombinant Saccharomyces cerevisiae strains to utilize the hemicellulose components of lignocellulosic feedstocks, the efficiency of xylose conversion to ethanol needs to be increased. In the present study, xylose-fermenting, haploid, yeast cells of the opposite mating type were hybridized to produce a diploid strain harboring two sets of xylose-assimilating genes encoding xylose reductase, xylitol dehydrogenase, and xylulokinase. The hybrid strain MN8140XX showed a 1.3- and 1.9-fold improvement in ethanol production compared to its parent strains MT8-1X405 and NBRC1440X, respectively. The rate of xylose consumption and ethanol production was also improved by the hybridization. This study revealed that the resulting improvements in fermentation ability arose due to chromosome doubling as well as the increase in the copy number of xylose assimilation genes. Moreover, compared to the parent strain, the MN8140XX strain exhibited higher ethanol production under elevated temperatures (38 °C) and acidic conditions (pH 3.8). Thus, the simple hybridization technique facilitated an increase in the xylose fermentation activity.
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Affiliation(s)
- Hiroko Kato
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodaicho, Nada, Kobe 657-8501, Japan
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Matano Y, Hasunuma T, Kondo A. Display of cellulases on the cell surface of Saccharomyces cerevisiae for high yield ethanol production from high-solid lignocellulosic biomass. BIORESOURCE TECHNOLOGY 2012; 108:128-33. [PMID: 22265982 DOI: 10.1016/j.biortech.2011.12.144] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Revised: 12/28/2011] [Accepted: 12/30/2011] [Indexed: 05/04/2023]
Abstract
Economically feasible processes for industrial cellulosic ethanol production requires increasing the final ethanol titer during fermentation due to the high energy demands of the subsequent ethanol distillation. In the present study, high-yield ethanol production was achieved by short-term liquefaction and fermentation of lignocellulose biomass in a novel drum-type rotary fermentation system using a yeast strain developed for cell-surface display of fungal endoglucanase, cellobiohydrolase, and β-glucosidase. In the presence of 10 FPU/g-biomass cellulase added, the recombinant cellulolytic strain produced 1.4-fold higher ethanol (89% of theoretical yield) from high-solid (200 g-dry weight/L) rice straw within 72 h of fermentation than wild type strain. Cell-surface engineering successfully reduced the amount of commercial enzyme required for the fermentation of cellulose. This study demonstrates that cellulases displayed on the yeast cell surface are capable of hydrolyzing cellulose that was not hydrolyzed by commercial cellulases, leading to increased sugar utilization for improved ethanol production.
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Affiliation(s)
- Yuki Matano
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
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Direct ethanol production from hemicellulosic materials of rice straw by use of an engineered yeast strain codisplaying three types of hemicellulolytic enzymes on the surface of xylose-utilizing Saccharomyces cerevisiae cells. J Biotechnol 2011; 158:203-10. [PMID: 21741417 DOI: 10.1016/j.jbiotec.2011.06.025] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Revised: 06/16/2011] [Accepted: 06/22/2011] [Indexed: 11/21/2022]
Abstract
The cost of the lignocellulose-hydrolyzing enzymes used in the saccharification process of ethanol production from biomass accounts for a relatively high proportion of total processing costs. Cell surface engineering technology has facilitated a reduction in these costs by integrating saccharification and fermentation processes into a recombinant microbe strain expressing heterologous enzymes on the cell surface. We constructed a recombinant Saccharomyces cerevisiae that not only hydrolyzed hemicelluloses by codisplaying endoxylanase from Trichoderma reesei, β-xylosidase from Aspergillus oryzae, and β-glucosidase from Aspergillus aculeatus but that also assimilated xylose through the expression of xylose reductase and xylitol dehydrogenase from Pichia stipitis and xylulokinase from S. cerevisiae. The recombinant strain successfully produced ethanol from rice straw hydrolysate consisting of hemicellulosic material containing xylan, xylooligosaccharides, and cellooligosaccharides without requiring the addition of sugar-hydrolyzing enzymes or detoxication. The ethanol titer of the strain was 8.2g/l after 72h fermentation, which was approximately 2.5-fold higher than that of the control strain. The yield (grams of ethanol per gram of total sugars in rice straw hydrolysate consumed) was 0.41g/g, which corresponded to 82% of the theoretical yield. The cell surface-engineered strain was thus highly effective for consolidating the process of ethanol production from hemicellulosic materials.
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Yamada R, Taniguchi N, Tanaka T, Ogino C, Fukuda H, Kondo A. Direct ethanol production from cellulosic materials using a diploid strain of Saccharomyces cerevisiae with optimized cellulase expression. BIOTECHNOLOGY FOR BIOFUELS 2011; 4:8. [PMID: 21496218 PMCID: PMC3095537 DOI: 10.1186/1754-6834-4-8] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 04/15/2011] [Indexed: 05/10/2023]
Abstract
BACKGROUND Hydrolysis of cellulose requires the action of the cellulolytic enzymes endoglucanase, cellobiohydrolase and β-glucosidase. The expression ratios and synergetic effects of these enzymes significantly influence the extent and specific rate of cellulose degradation. In this study, using our previously developed method to optimize cellulase-expression levels in yeast, we constructed a diploid Saccharomyces cerevisiae strain optimized for expression of cellulolytic enzymes, and attempted to improve the cellulose-degradation activity and enable direct ethanol production from rice straw, one of the most abundant sources of lignocellulosic biomass. RESULTS The engineered diploid strain, which contained multiple copies of three cellulase genes integrated into its genome, was precultured in molasses medium (381.4 mU/g wet cell), and displayed approximately six-fold higher phosphoric acid swollen cellulose (PASC) degradation activity than the parent haploid strain (63.5 mU/g wet cell). When used to ferment PASC, the diploid strain produced 7.6 g/l ethanol in 72 hours, with an ethanol yield that achieved 75% of the theoretical value, and also produced 7.5 g/l ethanol from pretreated rice straw in 72 hours. CONCLUSIONS We have developed diploid yeast strain optimized for expression of cellulolytic enzymes, which is capable of directly fermenting from cellulosic materials. Although this is a proof-of-concept study, it is to our knowledge, the first report of ethanol production from agricultural waste biomass using cellulolytic enzyme-expressing yeast without the addition of exogenous enzymes. Our results suggest that combining multigene expression optimization and diploidization in yeast is a promising approach for enhancing ethanol production from various types of lignocellulosic biomass.
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Affiliation(s)
- Ryosuke Yamada
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 657-8501, Japan
| | - Naho Taniguchi
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 657-8501, Japan
| | - Tsutomu Tanaka
- Organization of Advanced Science and Technology, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 657-8501, Japan
| | - Chiaki Ogino
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 657-8501, Japan
| | - Hideki Fukuda
- Organization of Advanced Science and Technology, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 657-8501, Japan
| | - Akihiko Kondo
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 657-8501, Japan
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Raw starch fermentation to ethanol by an industrial distiller’s yeast strain of Saccharomyces cerevisiae expressing glucoamylase and α-amylase genes. Biotechnol Lett 2011; 33:1643-8. [DOI: 10.1007/s10529-011-0613-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Accepted: 03/29/2011] [Indexed: 10/18/2022]
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