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Liu J, Ni Z, Jiao B, Hu Y, Sun Z, Wu D, Yuan Q, Han Y, Wang L. Comprehensive Transcriptomic Analysis of the Isolated Candida tropicalis with Enhanced Tolerance of Furfural Inhibitor. Int J Mol Sci 2025; 26:2999. [PMID: 40243641 PMCID: PMC11988566 DOI: 10.3390/ijms26072999] [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: 01/20/2025] [Revised: 03/15/2025] [Accepted: 03/22/2025] [Indexed: 04/18/2025] Open
Abstract
The Candida tropicalis (C. tropicalis) named YB-3 was isolated by the Atmospheric and room temperature plasma mutagenesis from 6.5 g/L furfural tolerance. The comprehensive transcriptomic analysis of YB-3 was performed. During the stress of furfural treatment, C. tropicalis YB-3 protected cells from oxidative stress damage by increasing the accumulation of the glutathione reductase gene and the expression of antioxidant enzymes, with the enhancement of the inositol phosphate synthase to maintain the structural integrity and transport function of the inner membrane system, thereby affecting the cells' tolerance. Through the gene knockout and exogenous verification, it was further confirmed that the pathways involved in the three genes of sulfate adenosine transferase gene, glutathione reductase gene, and inositol phosphate synthase gene had significant effects on improving the tolerance of the strain to furfural. The deep excavation of furfural-tolerant gene components and directional modification of C. tropicalis to enhance tolerance are key steps for improving the utilization rate of biomass.
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Affiliation(s)
- Jianguang Liu
- School of Biological Engineering, Institute of Biomass Science and Engineering, Henan University of Technology, Zhengzhou 450001, China
| | - Zifu Ni
- School of Biological Engineering, Institute of Biomass Science and Engineering, Henan University of Technology, Zhengzhou 450001, China
| | - Bingyu Jiao
- School of Biological Engineering, Institute of Biomass Science and Engineering, Henan University of Technology, Zhengzhou 450001, China
| | - Yuansen Hu
- School of Biological Engineering, Institute of Biomass Science and Engineering, Henan University of Technology, Zhengzhou 450001, China
| | - Zhongke Sun
- School of Biological Engineering, Institute of Biomass Science and Engineering, Henan University of Technology, Zhengzhou 450001, China
| | - Dapeng Wu
- School of Environment, Henan Normal University, Xinxiang 453001, China
| | - Qipeng Yuan
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Yuhuan Han
- School of Biological Engineering, Institute of Biomass Science and Engineering, Henan University of Technology, Zhengzhou 450001, China
| | - Le Wang
- School of Biological Engineering, Institute of Biomass Science and Engineering, Henan University of Technology, Zhengzhou 450001, China
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Tian L, Qi T, Zhang F, Tran VG, Yuan J, Wang Y, He N, Cao M. Synthetic biology approaches to improve tolerance of inhibitors in lignocellulosic hydrolysates. Biotechnol Adv 2025; 78:108477. [PMID: 39551454 DOI: 10.1016/j.biotechadv.2024.108477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2024] [Revised: 10/01/2024] [Accepted: 11/12/2024] [Indexed: 11/19/2024]
Abstract
Increasing attention is being focused on using lignocellulose for valuable products. Microbial decomposition can convert lignocellulose into renewable biofuels and other high-value bioproducts, contributing to sustainable development. However, the presence of inhibitors in lignocellulosic hydrolysates can negatively affect microorganisms during fermentation. Improving microbial tolerance to these hydrolysates is a major focus in metabolic engineering. Traditional detoxification methods increase costs, so there is a need for cheap and efficient cell-based detoxification strategies. Synthetic biology approaches offer several strategies for improving microbial tolerance, including redox balancing, membrane engineering, omics-guided technologies, expression of protectants and transcription factors, irrational engineering, cell flocculation, and other novel technologies. Advances in molecular biology, high-throughput sequencing, and artificial intelligence (AI) allow for precise strain modification and efficient industrial production. Developing AI-based computational models to guide synthetic biology efforts and creating large-scale heterologous libraries with automation and high-throughput technologies will be important for future research.
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Affiliation(s)
- Linyue Tian
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005, China; Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen 361005, China
| | - Tianqi Qi
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005, China
| | - Fenghui Zhang
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005, China
| | - Vinh G Tran
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Jifeng Yuan
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, Fujian 361102, China
| | - Yuanpeng Wang
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005, China
| | - Ning He
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005, China.
| | - Mingfeng Cao
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005, China; Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen 361005, China.
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Ren J, Zhang M, Guo X, Zhou X, Ding N, Lei C, Jia C, Wang Y, Zhao J, Dong Z, Lu D. Furfural tolerance of mutant Saccharomyces cerevisiae selected via ionizing radiation combined with adaptive laboratory evolution. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:117. [PMID: 39175057 PMCID: PMC11342514 DOI: 10.1186/s13068-024-02562-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 08/09/2024] [Indexed: 08/24/2024]
Abstract
BACKGROUND Lignocellulose is a renewable and sustainable resource used to produce second-generation biofuel ethanol to cope with the resource and energy crisis. Furfural is the most toxic inhibitor of Saccharomyces cerevisiae cells produced during lignocellulose treatment, and can reduce the ability of S. cerevisiae to utilize lignocellulose, resulting in low bioethanol yield. In this study, multiple rounds of progressive ionizing radiation was combined with adaptive laboratory evolution to improve the furfural tolerance of S. cerevisiae and increase the yield of ethanol. RESULTS In this study, the strategy of multiple rounds of progressive X-ray radiation combined with adaptive laboratory evolution significantly improved the furfural tolerance of brewing yeast. After four rounds of experiments, four mutant strains resistant to high concentrations of furfural were obtained (SCF-R1, SCF-R2, SCF-R3, and SCF-R4), with furfural tolerance concentrations of 4.0, 4.2, 4.4, and 4.5 g/L, respectively. Among them, the mutant strain SCF-R4 obtained in the fourth round of radiation had a cellular malondialdehyde content of 49.11 nmol/mg after 3 h of furfural stress, a weakening trend in mitochondrial membrane potential collapse, a decrease in accumulated reactive oxygen species, and a cell death rate of 12.60%, showing better cell membrane integrity, stable mitochondrial function, and an improved ability to limit reactive oxygen species production compared to the other mutant strains and the wild-type strain. In a fermentation medium containing 3.5 g/L furfural, the growth lag phase of the SCF-R4 mutant strain was shortened, and its growth ability significantly improved. After 96 h of fermentation, the ethanol production of the mutant strain SCF-R4 was 1.86 times that of the wild-type, indicating that with an increase in the number of irradiation rounds, the furfural tolerance of the mutant strain SCF-R4 was effectively enhanced. In addition, through genome-transcriptome analysis, potential sites related to furfural detoxification were identified, including GAL7, MAE1, PDC6, HXT1, AUS1, and TPK3. CONCLUSIONS These results indicate that multiple rounds of progressive X-ray radiation combined with adaptive laboratory evolution is an effective mutagenic strategy for obtaining furfural-tolerant mutants and that it has the potential to tap genes related to the furfural detoxification mechanism.
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Affiliation(s)
- Junle Ren
- Institute of Modern Physics, Chinese Academy of Sciences, No. 509 Nanchang Road, Lanzhou, 730000, Gansu, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Miaomiao Zhang
- Institute of Modern Physics, Chinese Academy of Sciences, No. 509 Nanchang Road, Lanzhou, 730000, Gansu, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaopeng Guo
- School of Life Science and Engineering, Lanzhou University of Technology, No. 36 Peng Jiaping, Lanzhou, 730050, Gansu, China.
| | - Xiang Zhou
- Institute of Modern Physics, Chinese Academy of Sciences, No. 509 Nanchang Road, Lanzhou, 730000, Gansu, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Nan Ding
- Institute of Modern Physics, Chinese Academy of Sciences, No. 509 Nanchang Road, Lanzhou, 730000, Gansu, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Cairong Lei
- Institute of Modern Physics, Chinese Academy of Sciences, No. 509 Nanchang Road, Lanzhou, 730000, Gansu, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chenglin Jia
- Institute of Modern Physics, Chinese Academy of Sciences, No. 509 Nanchang Road, Lanzhou, 730000, Gansu, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yajuan Wang
- Institute of Modern Physics, Chinese Academy of Sciences, No. 509 Nanchang Road, Lanzhou, 730000, Gansu, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jingru Zhao
- Institute of Modern Physics, Chinese Academy of Sciences, No. 509 Nanchang Road, Lanzhou, 730000, Gansu, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ziyi Dong
- Institute of Modern Physics, Chinese Academy of Sciences, No. 509 Nanchang Road, Lanzhou, 730000, Gansu, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Dong Lu
- Institute of Modern Physics, Chinese Academy of Sciences, No. 509 Nanchang Road, Lanzhou, 730000, Gansu, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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Yi X, Yang D, Xu X, Wang Y, Guo Y, Zhang M, Wang Y, He Y, Zhu J. Cold plasma pretreatment reinforces the lignocellulose-derived aldehyde inhibitors tolerance and bioethanol fermentability for Zymomonas mobilis. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:102. [PMID: 37322470 DOI: 10.1186/s13068-023-02354-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 05/29/2023] [Indexed: 06/17/2023]
Abstract
BACKGROUND Lignocellulose-derived aldehyde inhibitors seriously blocked the biorefinery of biofuels and biochemicals. To date, the economic production of lignocellulose-based products heavily relied on high productivities of fermenting strains. However, it was expensive and time-consuming for the achievable rational modification to strengthen stress tolerance robustness of aldehyde inhibitors. Here, it aimed to improve aldehyde inhibitors tolerance and cellulosic bioethanol fermentability for the chassis Zymomonas mobilis ZM4 pretreated using energy-efficient and eco-friendly cold plasma. RESULTS It was found that bioethanol fermentability was weaker in CSH (corn stover hydrolysates) than that in synthetic medium for Z. mobilis, and thus was attributed to the inhibition of the lignocellulose-derived aldehyde inhibitors in CSH. Convincingly, it further confirmed that the mixed aldehydes severely decreased bioethanol accumulation through additional aldehydes supplementary assays in synthetic medium. After assayed under different processing time (10-30 s), discharge power (80-160 W), and working pressure (120-180 Pa) using cold atmosphere plasma (CAP), it achieved the increased bioethanol fermentability for Z. mobilis after pretreated at the optimized parameters (20 s, 140 W and 165 Pa). It showed that cold plasma brought about three mutation sites including ZMO0694 (E220V), ZMO0843 (L471L) and ZMO0843 (P505H) via Genome resequencing-based SNPs (single nucleotide polymorphisms). A serial of differentially expressed genes (DEGs) were further identified as the potential contributors for stress tolerance via RNA-Seq sequencing, including ZMO0253 and ZMO_RS09265 (type I secretion outer membrane protein), ZMO1941 (Type IV secretory pathway protease TraF-like protein), ZMOr003 and ZMOr006 (16S ribosomal RNA), ZMO0375 and ZMO0374 (levansucrase) and ZMO1705 (thioredoxins). It enriched cellular process, followed by metabolic process and single-organism process for biological process. For KEGG analysis, the mutant was also referred to starch and sucrose metabolism, galactose metabolism and two-component system. Finally, but interestingly, it simultaneously achieved the enhanced stress tolerance capacity of aldehyde inhibitors and bioethanol fermentability in CSH for the mutant Z. mobilis. CONCLUSIONS Of several candidate genetic changes, the mutant Z. mobilis treated with cold plasma was conferred upon the facilitated aldehyde inhibitors tolerance and bioethanol production. This work would provide a strain biocatalyst for the efficient production of lignocellulosic biofuels and biochemicals.
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Affiliation(s)
- Xia Yi
- National-Local Joint Engineering Research Center for Biomass Refining and High-Quality Utilization, Changzhou University, Changzhou, 213164, China.
- Institute of Urban and Rural Mining, Changzhou University, Changzhou, 213164, China.
- Changzhou Key Laboratory of Biomass Green, Safe & High Value Utilization Technology, Changzhou University, Changzhou, 213164, Jiangsu, China.
| | - Dong Yang
- School of Pharmacy, Changzhou University, Changzhou, 213164, Jiangsu, China
| | - Xiaoyan Xu
- School of Pharmacy, Changzhou University, Changzhou, 213164, Jiangsu, China
| | - Youjun Wang
- School of Pharmacy, Changzhou University, Changzhou, 213164, Jiangsu, China
| | - Yan Guo
- School of Pharmacy, Changzhou University, Changzhou, 213164, Jiangsu, China
| | - Meng Zhang
- School of Pharmacy, Changzhou University, Changzhou, 213164, Jiangsu, China
| | - Yilong Wang
- School of Pharmacy, Changzhou University, Changzhou, 213164, Jiangsu, China
| | - Yucai He
- National-Local Joint Engineering Research Center for Biomass Refining and High-Quality Utilization, Changzhou University, Changzhou, 213164, China.
- School of Pharmacy, Changzhou University, Changzhou, 213164, Jiangsu, China.
| | - Jie Zhu
- National-Local Joint Engineering Research Center for Biomass Refining and High-Quality Utilization, Changzhou University, Changzhou, 213164, China.
- Institute of Urban and Rural Mining, Changzhou University, Changzhou, 213164, China.
- Changzhou Key Laboratory of Biomass Green, Safe & High Value Utilization Technology, Changzhou University, Changzhou, 213164, Jiangsu, China.
- School of Pharmacy, Changzhou University, Changzhou, 213164, Jiangsu, China.
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5
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Cao LY, Liu CG, Yang SH, Bai FW. Regulation of biofilm formation in Zymomonas mobilis to enhance stress tolerance by heterologous expression of pfs and luxS. Front Bioeng Biotechnol 2023; 11:1130405. [PMID: 36845188 PMCID: PMC9945106 DOI: 10.3389/fbioe.2023.1130405] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 01/27/2023] [Indexed: 02/11/2023] Open
Abstract
Zymomonas mobilis is a potential alternative of Saccharomyces cerevisiae to produce cellulosic ethanol with strengths in cofactor balance, but its lower tolerance to inhibitors in the lignocellulosic hydrolysate restricts the application. Although biofilm can improve bacteria stress tolerance, regulating biofilm formation in Z. mobilis is still a challenge. In this work, we constructed a pathway by heterologous expressing pfs and luxS from Escherichia coli in Z. mobilis to produce AI-2 (autoinducer 2), a universal quorum-sensing signal molecule, to control cell morphology for enhancing stress tolerance. Unexpectedly, the results suggested that neither endogenous AI-2 nor exogenous AI-2 promoted biofilm formation, while heterologous expression of pfs can significantly raise biofilm. Therefore, we proposed that the main factor in assisting biofilm formation was the product accumulated due to heterologous expression of pfs, like methylated DNA. Consequently, ZM4::pfs produced more biofilm, which presented an enhanced tolerance to acetic acid. All these findings provide a novel strategy to improve the stress tolerance of Z. mobilis by enhancing biofilm formation for efficient production of lignocellulosic ethanol and other value-added chemical products.
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Affiliation(s)
- Lian-Ying Cao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Science, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Chen-Guang Liu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Science, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China,*Correspondence: Chen-Guang Liu,
| | - Shi-Hui Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, China
| | - Feng-Wu Bai
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Science, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
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Yan X, Wang X, Yang Y, Wang Z, Zhang H, Li Y, He Q, Li M, Yang S. Cysteine supplementation enhanced inhibitor tolerance of Zymomonas mobilis for economic lignocellulosic bioethanol production. BIORESOURCE TECHNOLOGY 2022; 349:126878. [PMID: 35189331 DOI: 10.1016/j.biortech.2022.126878] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 02/15/2022] [Accepted: 02/16/2022] [Indexed: 05/26/2023]
Abstract
Inhibitors in lignocellulosic hydrolysates are toxic to Zymomonas mobilis and reduce its bioethanol production. This study revealed cysteine supplementation enhanced furfural tolerance in Z. mobilis with a 2-fold biomass increase. Transcriptomic study illustrated that cysteine biosynthesis pathway was down-regulated while cysteine catabolism was up-regulated with cysteine supplementation. Mutants for genes involved in cysteine metabolism were constructed, and metabolites in cysteine metabolic pathway including methionine, glutathione, NaHS, glutamate, and pyruvate were supplemented into media. Cysteine supplementation boosted glutathione synthesis or H2S release effectively in Z. mobilis leading to the reduced accumulation of reactive oxygen species (ROS) induced by furfural, while pyruvate and glutamate produced in the H2S generation pathway promoted cell growth by serving as the carbon or nitrogen source. Finally, cysteine supplementation was confirmed to enhance Z. mobilis tolerance against ethanol, acetate, and corncob hydrolysate with an enhanced ethanol productivity from 0.38 to 0.55 g-1∙L-1∙h-1.
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Affiliation(s)
- Xiongying Yan
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, and School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Xia Wang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, and School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Yongfu Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, and School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Zhen Wang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, and School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Haoyu Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, and School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Yang Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, and School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Qiaoning He
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, and School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Mian Li
- Zhejiang Huakang Pharmaceutical Co., Ltd., Kaihua County, Zhejiang, China
| | - Shihui Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, and School of Life Sciences, Hubei University, Wuhan 430062, China.
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Hu D, Wang Z, He M, Ma Y. Functional Gene Identification and Corresponding Tolerant Mechanism of High Furfural-Tolerant Zymomonas mobilis Strain F211. Front Microbiol 2021; 12:736583. [PMID: 34858360 PMCID: PMC8631904 DOI: 10.3389/fmicb.2021.736583] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 10/15/2021] [Indexed: 12/21/2022] Open
Abstract
Furfural is a major inhibitor in lignocellulose hydrolysate for Zymomonas mobilis. A mutant F211 strain with high furfural tolerance was obtained from our previous study. Thus, its key tolerance mechanism was studied in the present study. The function of mutated genes in F211 was identified by functional complementation experiments, revealing that the improved furfural tolerance was resulted from the C493T mutation of the ZCP4_0270 gene promoting cell flocculation and the mutation (G1075A)/downregulation of ZCP4_0970. Comparative transcriptome analysis revealed 139 differentially expressed genes between F211 and the control, CP4, in response to furfural stress. In addition, the reliability of the RNA-Seq data was also confirmed. The potential tolerance mechanism was further demonstrated by functional identification of tolerance genes as follows: (I) some upregulated or downregulated genes increase the levels of NAD(P)H, which is involved in the reduction of furfural to less toxic furfuryl alcohol, thus accelerating the detoxification of furfural; (II) the mutated ZCP4_0270 and upregulated cellulose synthetase gene (ZCP4_0241 and ZCP4_0242) increased flocculation to resist furfural stress; (III) upregulated molecular chaperone genes promote protein synthesis and repair stress-damaged proteins; and (IV) transporter genes ZCP4_1623–1,625 and ZCP4_1702–1703 were downregulated, saving energy for cell growth. The furfural-tolerant mechanism and corresponding functional genes were revealed, which provides a theoretical basis for developing robust chassis strains for synthetic biology efforts.
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Affiliation(s)
- Dongsheng Hu
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Zhiquan Wang
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,School of Marine Science and Technology, Tianjin University, Tianjin, China
| | - Mingxiong He
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs), Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu, China
| | - Yuanyuan Ma
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,School of Marine Science and Technology, Tianjin University, Tianjin, China
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Munro LJ, Kell DB. Intelligent host engineering for metabolic flux optimisation in biotechnology. Biochem J 2021; 478:3685-3721. [PMID: 34673920 PMCID: PMC8589332 DOI: 10.1042/bcj20210535] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 09/22/2021] [Accepted: 09/24/2021] [Indexed: 12/13/2022]
Abstract
Optimising the function of a protein of length N amino acids by directed evolution involves navigating a 'search space' of possible sequences of some 20N. Optimising the expression levels of P proteins that materially affect host performance, each of which might also take 20 (logarithmically spaced) values, implies a similar search space of 20P. In this combinatorial sense, then, the problems of directed protein evolution and of host engineering are broadly equivalent. In practice, however, they have different means for avoiding the inevitable difficulties of implementation. The spare capacity exhibited in metabolic networks implies that host engineering may admit substantial increases in flux to targets of interest. Thus, we rehearse the relevant issues for those wishing to understand and exploit those modern genome-wide host engineering tools and thinking that have been designed and developed to optimise fluxes towards desirable products in biotechnological processes, with a focus on microbial systems. The aim throughput is 'making such biology predictable'. Strategies have been aimed at both transcription and translation, especially for regulatory processes that can affect multiple targets. However, because there is a limit on how much protein a cell can produce, increasing kcat in selected targets may be a better strategy than increasing protein expression levels for optimal host engineering.
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Affiliation(s)
- Lachlan J. Munro
- Novo Nordisk Foundation Centre for Biosustainability, Technical University of Denmark, Building 220, Kemitorvet, 2800 Kgs. Lyngby, Denmark
| | - Douglas B. Kell
- Novo Nordisk Foundation Centre for Biosustainability, Technical University of Denmark, Building 220, Kemitorvet, 2800 Kgs. Lyngby, Denmark
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown St, Liverpool L69 7ZB, U.K
- Mellizyme Biotechnology Ltd, IC1, Liverpool Science Park, 131 Mount Pleasant, Liverpool L3 5TF, U.K
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9
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Nouri H, Moghimi H, Marashi SA, Elahi E. Impact of hfq and sigE on the tolerance of Zymomonas mobilis ZM4 to furfural and acetic acid stresses. PLoS One 2020; 15:e0240330. [PMID: 33035245 PMCID: PMC7546472 DOI: 10.1371/journal.pone.0240330] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 09/23/2020] [Indexed: 01/14/2023] Open
Abstract
Zymomonas mobilis, as an ethanologenic microorganism with many desirable industrial features, faces crucial obstacles in the lignocellulosic ethanol production process. A significant hindrance occurs during the pretreatment procedure that not only produces fermentable sugars but also releases severe toxic compounds. As diverse parts of regulation networks are involved in different aspects of complicated tolerance to inhibitors, we developed ZM4-hfq and ZM4-sigE strains, in which hfq and sigE genes were overexpressed, respectively. ZM4-hfq is a transcription regulator and ZM4-sigE is a transcription factor that are involved in multiple stress responses. In the present work, by overexpressing these two genes, we evaluated their impact on the Z. mobilis tolerance to furfural, acetic acid, and sugarcane bagasse hydrolysates. Both recombinant strains showed increased growth rates and ethanol production levels compared to the parental strain. Under a high concentration of furfural, the growth rate of ZM4-hfq was more inhibited compared to ZM4-sigE. More precisely, fermentation performance of ZM4-hfq revealed that the yield of ethanol production was less than that of ZM4-sigE, because more unused sugar had remained in the medium. In the case of acetic acid, ZM4-sigE was the superior strain and produced four and two-fold more ethanol compared to the parental strain and ZM4-hfq, respectively. Comparison of inhibitor tolerance between single and multiple toxic inhibitors in the fermentation of sugarcane bagasse hydrolysate by ZM4-sigE strain showed similar results. In addition, ethanol production performance was considerably higher in ZM4-sigE as well. Finally, the results of the qPCR analysis suggested that under both furfural and acetic acid treatment experiments, overproduction of both hfq and sigE improves the Z. mobilis tolerance and its ethanol production capability. Overall, our study showed the vital role of the regulatory elements to overcome the obstacles in lignocellulosic biomass-derived ethanol and provide a platform for further improvement by directed evolution or systems metabolic engineering tools.
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Affiliation(s)
- Hoda Nouri
- Department of Microbial Biotechnology, School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Hamid Moghimi
- Department of Microbial Biotechnology, School of Biology, College of Science, University of Tehran, Tehran, Iran
- * E-mail:
| | - Sayed-Amir Marashi
- Department of Biotechnology, College of Science, University of Tehran, Tehran, Iran
| | - Elahe Elahi
- School of Biology, College of Science, University of Tehran, Tehran, Iran
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Fuchino K, Bruheim P. Increased salt tolerance in Zymomonas mobilis strain generated by adaptative evolution. Microb Cell Fact 2020; 19:147. [PMID: 32690090 PMCID: PMC7372843 DOI: 10.1186/s12934-020-01406-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 07/13/2020] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Ethanologenic alphaproteobacterium Zymomonas mobilis has been acknowledged as a promising biofuel producer. There have been numerous efforts to engineer this species applicable for an industrial-scale bioethanol production. Although Z. mobilis is robustly resilient to certain abiotic stress such as ethanol, the species is known to be sensitive to saline stress at a mild concentration, which hampers its industrial use as an efficient biocatalyst. To overcome this issue, we implemented a laboratory adaptive evolution approach to obtain salt tolerant Z. mobilis strain. RESULTS During an adaptive evolution, we biased selection by cell morphology to exclude stressed cells. The evolved strains significantly improved growth and ethanol production in the medium supplemented with 0.225 M NaCl. Furthermore, comparative metabolomics revealed that the evolved strains did not accumulate prototypical osmolytes, such as proline, to counter the stress during their growth. The sequenced genomes of the studied strains suggest that the disruption of ZZ6_1149 encoding carboxyl-terminal protease was likely responsible for the improved phenotype. CONCLUSIONS The present work successfully generated strains able to grow and ferment glucose under the saline condition that severely perturbs parental strain physiology. Our approach to generate strains, cell shape-based diagnosis and selection, might be applicable to other kinds of strain engineering in Z. mobilis.
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Affiliation(s)
- Katsuya Fuchino
- Department of Biotechnology and Food Science, Norwegian University of Science and Technology, Trondheim, Norway.
| | - Per Bruheim
- Department of Biotechnology and Food Science, Norwegian University of Science and Technology, Trondheim, Norway
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11
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Todhanakasem T, Wu B, Simeon S. Perspectives and new directions for bioprocess optimization using Zymomonas mobilis in the ethanol production. World J Microbiol Biotechnol 2020; 36:112. [PMID: 32656581 DOI: 10.1007/s11274-020-02885-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 06/29/2020] [Indexed: 12/28/2022]
Abstract
Zymomonas mobilis is an ethanologenic microbe that has a demonstrated potential for use in lignocellulosic biorefineries for bioethanol production. Z. mobilis exhibits a number of desirable characteristics for use as an ethanologenic microbe, with capabilities for metabolic engineering and bioprocess modification. Many advanced genetic tools, including mutation techniques, screening methods and genome editing have been successively performed to improve various Z. mobilis strains as potential consolidated ethanologenic microbes. Many bioprocess strategies have also been applied to this organism for bioethanol production. Z. mobilis biofilm reactors have been modified with various benefits, including high bacterial populations, less fermentation times, high productivity, high cell stability, resistance to the high concentration of substrates and toxicity, and higher product recovery. We suggest that Z. mobilis biofilm reactors could be used in bioethanol production using lignocellulosic substrates under batch, continuous and repeated batch processes.
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Affiliation(s)
- Tatsaporn Todhanakasem
- Department of Agro- Industry, Faculty of Biotechnology, Assumption University, Ramkhamhaeng Road, Bangkapi, Bangkok, 10240, Thailand.
| | - Bo Wu
- Biomass Energy Technology Research Center, Biogas Institute of Ministry of Agriculture and Rural Affairs, Renmin Rd. S 4-13, Chengdu, 610041, China
| | - Saw Simeon
- Absolute Clean Energy Public Company Limited, ITF Tower 7th Floor, Silom Road, Bang Rak, Bangkok, 10500, Thailand
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Wang WT, Dai LC, Wu B, Qi BF, Huang TF, Hu GQ, He MX. Biochar-mediated enhanced ethanol fermentation (BMEEF) in Zymomonas mobilis under furfural and acetic acid stress. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:28. [PMID: 32127915 PMCID: PMC7045489 DOI: 10.1186/s13068-020-1666-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 01/22/2020] [Indexed: 05/19/2023]
Abstract
BACKGROUND Pretreatment of lignocellulosic biomass generates different types of inhibitors (e.g., furfural and acetic acid), which could remarkably inhibit subsequent ethanol fermentation. Here, biochar as an additive in the fermentation broth was first applied to enhance ethanol production by Z. mobilis wild-type strain ZM4 in the presence of typical inhibitors. RESULTS This study showed that the biochar-mediated tolerance to furfural and acetic acid for the strain Z. mobilis ZM4 was the highest reported level, resulting in much higher ethanol productivity under stress conditions than that in non-treated conditions. Further analysis showed that adsorptive detoxification was not the controlling factor for enhanced ethanol production under stress conditions, attributed to its low removal of furfural (< 20%) and incapability of acetic acid removal. When biochar was filtered from the biochar-treated inhibitor-containing broth, it still showed enhanced ethanol production. Furthermore, Z. mobilis immobilized on biochar was also observed. Thus, biochar extracts in the fermentation broth and cell immobilization on biochar might be the controlling factors for enhanced ethanol production under stress conditions. CONCLUSIONS These results indicate that biochar-mediated enhanced ethanol fermentation (BMEEF) might be a promising strategy for ethanol production from lignocellulosic biomass.
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Affiliation(s)
- Wei-ting Wang
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs), Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041 People’s Republic of China
- Graduate School of Chinese Academy of Agricultural Science, Beijing, 100081 People’s Republic of China
| | - Li-chun Dai
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs), Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041 People’s Republic of China
| | - Bo Wu
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs), Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041 People’s Republic of China
| | - Bu-fan Qi
- College of Pharmacy and Biological Engineering, Chengdu University, No. 2025, Cheng Luo Road, Chengdu, 610106 People’s Republic of China
| | - Tian-fang Huang
- Chengdu Institute of Biology, Chinese Academy of Sciences, Section 4-9, Renmin Rd. South, Chengdu, 610041 People’s Republic of China
| | - Guo-quan Hu
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs), Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041 People’s Republic of China
| | - Ming-xiong He
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs), Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041 People’s Republic of China
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13
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Yang Q, Yang Y, Tang Y, Wang X, Chen Y, Shen W, Zhan Y, Gao J, Wu B, He M, Chen S, Yang S. Development and characterization of acidic-pH-tolerant mutants of Zymomonas mobilis through adaptation and next-generation sequencing-based genome resequencing and RNA-Seq. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:144. [PMID: 32817760 PMCID: PMC7427070 DOI: 10.1186/s13068-020-01781-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 08/04/2020] [Indexed: 05/19/2023]
Abstract
BACKGROUND Acid pretreatment is a common strategy used to break down the hemicellulose component of the lignocellulosic biomass to release pentoses, and a subsequent enzymatic hydrolysis step is usually applied to release hexoses from the cellulose. The hydrolysate after pretreatment and enzymatic hydrolysis containing both hexoses and pentoses can then be used as substrates for biochemical production. However, the acid-pretreated liquor can also be directly used as the substrate for microbial fermentation, which has an acidic pH and contains inhibitory compounds generated during pretreatment. Although the natural ethanologenic bacterium Zymomonas mobilis can grow in a broad range of pH 3.5 ~ 7.5, cell growth and ethanol fermentation are still affected under acidic-pH conditions below pH 4.0. RESULTS In this study, adaptive laboratory evolution (ALE) strategy was applied to adapt Z. mobilis under acidic-pH conditions. Two mutant strains named 3.6M and 3.5M with enhanced acidic pH tolerance were selected and confirmed, of which 3.5M grew better than ZM4 but worse than 3.6M in acidic-pH conditions that is served as a reference strain between 3.6M and ZM4 to help unravel the acidic-pH tolerance mechanism. Mutant strains 3.5M and 3.6M exhibited 50 ~ 130% enhancement on growth rate, 4 ~ 9 h reduction on fermentation time to consume glucose, and 20 ~ 63% improvement on ethanol productivity than wild-type ZM4 at pH 3.8. Next-generation sequencing (NGS)-based whole-genome resequencing (WGR) and RNA-Seq technologies were applied to unravel the acidic-pH tolerance mechanism of mutant strains. WGR result indicated that compared to wild-type ZM4, 3.5M and 3.6M have seven and five single nucleotide polymorphisms (SNPs), respectively, among which four are shared in common. Additionally, RNA-Seq result showed that the upregulation of genes involved in glycolysis and the downregulation of flagellar and mobility related genes would help generate and redistribute cellular energy to resist acidic pH while keeping normal biological processes in Z. mobilis. Moreover, genes involved in RND efflux pump, ATP-binding cassette (ABC) transporter, proton consumption, and alkaline metabolite production were significantly upregulated in mutants under the acidic-pH condition compared with ZM4, which could help maintain the pH homeostasis in mutant strains for acidic-pH resistance. Furthermore, our results demonstrated that in mutant 3.6M, genes encoding F1F0 ATPase to pump excess protons out of cells were upregulated under pH 3.8 compared to pH 6.2. This difference might help mutant 3.6M manage acidic conditions better than ZM4 and 3.5M. A few gene targets were then selected for genetics study to explore their role in acidic pH tolerance, and our results demonstrated that the expression of two operons in the shuttle plasmids, ZMO0956-ZMO0958 encoding cytochrome bc1 complex and ZMO1428-ZMO1432 encoding RND efflux pump, could help Z. mobilis tolerate acidic-pH conditions. CONCLUSION An acidic-pH-tolerant mutant 3.6M obtained through this study can be used for commercial bioethanol production under acidic fermentation conditions. In addition, the molecular mechanism of acidic pH tolerance of Z. mobilis was further proposed, which can facilitate future research on rational design of synthetic microorganisms with enhanced tolerance against acidic-pH conditions. Moreover, the strategy developed in this study combining approaches of ALE, genome resequencing, RNA-Seq, and classical genetics study for mutant evolution and characterization can be applied in other industrial microorganisms.
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Affiliation(s)
- Qing Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province and School of Life Sciences, Hubei University, Wuhan, 430062 China
| | - Yongfu Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province and School of Life Sciences, Hubei University, Wuhan, 430062 China
| | - Ying Tang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province and School of Life Sciences, Hubei University, Wuhan, 430062 China
| | - Xia Wang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province and School of Life Sciences, Hubei University, Wuhan, 430062 China
| | - Yunhao Chen
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province and School of Life Sciences, Hubei University, Wuhan, 430062 China
| | - Wei Shen
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province and School of Life Sciences, Hubei University, Wuhan, 430062 China
| | - Yangyang Zhan
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province and School of Life Sciences, Hubei University, Wuhan, 430062 China
| | - Junjie Gao
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province and School of Life Sciences, Hubei University, Wuhan, 430062 China
| | - Bo Wu
- Key Laboratory of Development and Application of Rural Renewable Energy, Biomass Energy Technology Research Centre, Biogas Institute of Ministry of Agriculture, South Renmin Road, Chengdu, 610041 China
| | - Mingxiong He
- Key Laboratory of Development and Application of Rural Renewable Energy, Biomass Energy Technology Research Centre, Biogas Institute of Ministry of Agriculture, South Renmin Road, Chengdu, 610041 China
| | - Shouwen Chen
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province and School of Life Sciences, Hubei University, Wuhan, 430062 China
| | - Shihui Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province and School of Life Sciences, Hubei University, Wuhan, 430062 China
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Singhvi MS, Gokhale DV. Lignocellulosic biomass: Hurdles and challenges in its valorization. Appl Microbiol Biotechnol 2019; 103:9305-9320. [DOI: 10.1007/s00253-019-10212-7] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 10/17/2019] [Accepted: 10/20/2019] [Indexed: 12/13/2022]
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15
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Xia J, Yang Y, Liu CG, Yang S, Bai FW. Engineering Zymomonas mobilis for Robust Cellulosic Ethanol Production. Trends Biotechnol 2019; 37:960-972. [DOI: 10.1016/j.tibtech.2019.02.002] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 02/10/2019] [Accepted: 02/11/2019] [Indexed: 10/27/2022]
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16
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He X, Xue T, Ma Y, Zhang J, Wang Z, Hong J, Hui L, Qiao J, Song H, Zhang M. Identification of functional butanol-tolerant genes from Escherichia coli mutants derived from error-prone PCR-based whole-genome shuffling. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:73. [PMID: 30976323 PMCID: PMC6442406 DOI: 10.1186/s13068-019-1405-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 03/12/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Butanol is an important biofuel and chemical. The development of butanol-tolerant strains and the identification of functional butanol-tolerant genes is essential for high-yield bio-butanol production due to the toxicity of butanol. RESULTS Escherichia coli BW25113 was subjected for the first time to error-prone PCR-based whole-genome shuffling. The resulting mutants BW1847 and BW1857 were found to tolerate 2% (v/v) butanol and short-chain alcohols, including ethanol, isobutanol, and 1-pentanol. The mutants exhibited good stability under butanol stress, indicating that they are potential host strains for the construction of butanol pathways. BW1847 had better butanol tolerance than BW1857 under 0-0.75% (v/v) butanol stress, but showed a lower tolerance than BW1857 under 1.25-2% (v/v) butanol stress. Genome resequencing and PCR confirmation revealed that BW1847 and BW1857 had nine and seven single nucleotide polymorphisms, respectively, and a common 14-kb deletion. Functional complementation experiments of the SNPs and deleted genes demonstrated that the mutations of acrB and rob gene and the deletion of TqsA increased the tolerance of the two mutants to butanol. Genome-wide site-specific mutated strains DT385 (acrB C1198T) and DT900 (rob AT686-7) also showed significant tolerance to butanol and had higher butanol efflux ability than the control, further demonstrating that their mutations yield an inactive protein that enhances butanol resistance characteristics. CONCLUSIONS Stable E. coli mutants with enhanced short alcohols and high concentrations of butanol tolerance were obtained through a rapid and effective method. The key genes of butanol tolerance in the two mutants were identified by comparative functional genomic analysis.
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Affiliation(s)
- Xueting He
- Biomass Conversion Laboratory, R&D Center for Petrochemical Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
| | - Tingli Xue
- Biomass Conversion Laboratory, R&D Center for Petrochemical Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
| | - Yuanyuan Ma
- Biomass Conversion Laboratory, R&D Center for Petrochemical Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Frontier Technology Research Institute, Tianjin University, Tianjin, 30072 People’s Republic of China
- Collaborative Innovation Centre of Chemical Science and Engineering (Tianjin), Tianjin, 300072 China
- Key Laboratory of Systems Bioengineering (Ministry of Education), SynBio Research Platform, Tianjin University, Tianjin, 300072 China
| | - Junyan Zhang
- Biomass Conversion Laboratory, R&D Center for Petrochemical Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
| | - Zhiquan Wang
- Biomass Conversion Laboratory, R&D Center for Petrochemical Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
| | - Jiefang Hong
- Biomass Conversion Laboratory, R&D Center for Petrochemical Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
| | - Lanfeng Hui
- Tianjin Key Laboratory of Pulp and Paper, Tianjin University of Science and Technology, Tianjin, 300457 China
| | - Jianjun Qiao
- Collaborative Innovation Centre of Chemical Science and Engineering (Tianjin), Tianjin, 300072 China
- Key Laboratory of Systems Bioengineering (Ministry of Education), SynBio Research Platform, Tianjin University, Tianjin, 300072 China
| | - Hao Song
- Collaborative Innovation Centre of Chemical Science and Engineering (Tianjin), Tianjin, 300072 China
- Key Laboratory of Systems Bioengineering (Ministry of Education), SynBio Research Platform, Tianjin University, Tianjin, 300072 China
| | - Minhua Zhang
- Biomass Conversion Laboratory, R&D Center for Petrochemical Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Frontier Technology Research Institute, Tianjin University, Tianjin, 30072 People’s Republic of China
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Wang W, Wu B, Qin H, Liu P, Qin Y, Duan G, Hu G, He M. Genome shuffling enhances stress tolerance of Zymomonas mobilis to two inhibitors. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:288. [PMID: 31890016 PMCID: PMC6913010 DOI: 10.1186/s13068-019-1631-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 12/05/2019] [Indexed: 05/19/2023]
Abstract
BACKGROUND Furfural and acetic acid are the two major inhibitors generated during lignocellulose pretreatment and hydrolysis, would severely inhibit the cell growth, metabolism, and ethanol fermentation efficiency of Zymomonas mobilis. Effective genome shuffling mediated by protoplast electrofusion was developed and then applied to Z. mobilis. RESULTS After two rounds of genome shuffling, 10 different mutants with improved cell growth and ethanol yield in the presence of 5.0 g/L acetic acid and 3.0 g/L furfural were obtained. The two most prominent genome-shuffled strains, 532 and 533, were further investigated along with parental strains in the presence of 7.0 g/L acetic acid and 3.0 g/L furfural. The results showed that mutants 532 and 533 were superior to the parental strain AQ8-1 in the presence of 7.0 g/L acetic acid, with a shorter fermentation time (30 h) and higher productivity than AQ8-1. Mutant 533 exhibited subtle differences from parental strain F34 in the presence of 3.0 g/L furfural. Mutations present in 10 genome-shuffled strains were identified via whole-genome resequencing, and the source of each mutation was identified as either de novo mutation or recombination of the parent genes. CONCLUSIONS These results indicate that genome shuffling is an efficient method for enhancing stress tolerance in Z. mobilis. The engineered strains generated in this study could be potential cellulosic ethanol producers in the future.
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Affiliation(s)
- Weiting Wang
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs), Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041 People’s Republic of China
- Graduate School of Chinese Academy of Agricultural Science, Beijing, 100081 People’s Republic of China
| | - Bo Wu
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs), Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041 People’s Republic of China
| | - Han Qin
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs), Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041 People’s Republic of China
| | - Panting Liu
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs), Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041 People’s Republic of China
- Graduate School of Chinese Academy of Agricultural Science, Beijing, 100081 People’s Republic of China
| | - Yao Qin
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs), Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041 People’s Republic of China
- College of Pharmacy and Biological Engineering, Chengdu University, Chengdu, 610041 People’s Republic of China
| | - Guowei Duan
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs), Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041 People’s Republic of China
- Graduate School of Chinese Academy of Agricultural Science, Beijing, 100081 People’s Republic of China
| | - Guoquan Hu
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs), Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041 People’s Republic of China
- Graduate School of Chinese Academy of Agricultural Science, Beijing, 100081 People’s Republic of China
| | - Mingxiong He
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs), Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041 People’s Republic of China
- Graduate School of Chinese Academy of Agricultural Science, Beijing, 100081 People’s Republic of China
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18
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Biot-Pelletier D, Pinel D, Larue K, Martin VJJ. Determinants of selection in yeast evolved by genome shuffling. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:282. [PMID: 30356826 PMCID: PMC6190656 DOI: 10.1186/s13068-018-1283-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 10/06/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Genome shuffling (GS) is a widely adopted methodology for the evolutionary engineering of desirable traits in industrially relevant microorganisms. We have previously used genome shuffling to generate a strain of Saccharomyces cerevisiae that is tolerant to the growth inhibitors found in a lignocellulosic hydrolysate. In this study, we expand on previous work by performing a population-wide genomic survey of our genome shuffling experiment and dissecting the molecular determinants of the evolved phenotype. RESULTS Whole population whole-genome sequencing was used to survey mutations selected during the experiment and extract allele frequency time series. Using growth curve assays on single point mutants and backcrossed derivatives, we explored the genetic architecture of the selected phenotype and detected examples of epistasis. Our results reveal cohorts of strongly correlated mutations, suggesting prevalent genetic hitchhiking and the presence of pre-existing founder mutations. From the patterns of apparent selection and the results of direct phenotypic assays, our results identify key driver mutations and deleterious hitchhikers. CONCLUSIONS We use these data to propose a model of inhibitor tolerance in our GS mutants. Our results also suggest a role for compensatory evolution and epistasis in our genome shuffling experiment and illustrate the impact of historical contingency on the outcomes of evolutionary engineering.
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Affiliation(s)
- Damien Biot-Pelletier
- Department of Biology, Centre for Structural and Functional Genomics, Centre for Applied Synthetic Biology, Concordia University, 7141 Sherbrooke Street West, Montreal, QC H4B 1R6 Canada
- Present Address: Lallemand Inc., Montréal, QC H4P 2R2 Canada
| | - Dominic Pinel
- Department of Biology, Centre for Structural and Functional Genomics, Centre for Applied Synthetic Biology, Concordia University, 7141 Sherbrooke Street West, Montreal, QC H4B 1R6 Canada
- Present Address: Amyris Inc, Emeryville, CA 94608 USA
| | - Kane Larue
- Department of Biology, Centre for Structural and Functional Genomics, Centre for Applied Synthetic Biology, Concordia University, 7141 Sherbrooke Street West, Montreal, QC H4B 1R6 Canada
- Present Address: Charles River Laboratories, Senneville, QC H9X 3R3 Canada
| | - Vincent J. J. Martin
- Department of Biology, Centre for Structural and Functional Genomics, Centre for Applied Synthetic Biology, Concordia University, 7141 Sherbrooke Street West, Montreal, QC H4B 1R6 Canada
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