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Asefi S, Nouri H, Pourmohammadi G, Moghimi H. Comprehensive network of stress-induced responses in Zymomonas mobilis during bioethanol production: from physiological and molecular responses to the effects of system metabolic engineering. Microb Cell Fact 2024; 23:180. [PMID: 38890644 PMCID: PMC11186258 DOI: 10.1186/s12934-024-02459-1] [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: 10/05/2023] [Accepted: 06/13/2024] [Indexed: 06/20/2024] Open
Abstract
Nowadays, biofuels, especially bioethanol, are becoming increasingly popular as an alternative to fossil fuels. Zymomonas mobilis is a desirable species for bioethanol production due to its unique characteristics, such as low biomass production and high-rate glucose metabolism. However, several factors can interfere with the fermentation process and hinder microbial activity, including lignocellulosic hydrolysate inhibitors, high temperatures, an osmotic environment, and high ethanol concentration. Overcoming these limitations is critical for effective bioethanol production. In this review, the stress response mechanisms of Z. mobilis are discussed in comparison to other ethanol-producing microbes. The mechanism of stress response is divided into physiological (changes in growth, metabolism, intracellular components, and cell membrane structures) and molecular (up and down-regulation of specific genes and elements of the regulatory system and their role in expression of specific proteins and control of metabolic fluxes) changes. Systemic metabolic engineering approaches, such as gene manipulation, overexpression, and silencing, are successful methods for building new metabolic pathways. Therefore, this review discusses systems metabolic engineering in conjunction with systems biology and synthetic biology as an important method for developing new strains with an effective response mechanism to fermentation stresses during bioethanol production. Overall, understanding the stress response mechanisms of Z. mobilis can lead to more efficient and effective bioethanol production.
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Affiliation(s)
- Shaqayeq Asefi
- Department of Microbial Biotechnology, School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Hoda Nouri
- Department of Microbial Biotechnology, School of Biology, College of Science, University of Tehran, Tehran, Iran.
| | - Golchehr Pourmohammadi
- 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.
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Saxena A, Hussain A, Parveen F, Ashfaque M. Current status of metabolic engineering of microorganisms for bioethanol production by effective utilization of pentose sugars of lignocellulosic biomass. Microbiol Res 2023; 276:127478. [PMID: 37625339 DOI: 10.1016/j.micres.2023.127478] [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: 05/08/2023] [Revised: 08/01/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023]
Abstract
Lignocellulosic biomass, consisting of homo- and heteropolymeric sugars, acts as a substrate for the generation of valuable biochemicals and biomaterials. The readily available hexoses are easily utilized by microbes due to the presence of transporters and native metabolic pathways. But, utilization of pentose sugar viz., xylose and arabinose are still challenging due to several reasons including (i) the absence of the particular native pathways and transporters, (ii) the presence of inhibitors, and (iii) lower uptake of pentose sugars. These challenges can be overcome by manipulating metabolic pathways/glycosidic enzymes cascade by using genetic engineering tools involving inverse-metabolic engineering, ex-vivo isomerization, Adaptive Laboratory Evolution, Directed Metabolic Engineering, etc. Metabolic engineering of bacteria and fungi for the utilization of pentose sugars for bioethanol production is the focus area of research in the current decade. This review outlines current approaches to biofuel development and strategies involved in the metabolic engineering of different microbes that can uptake pentose for bioethanol production.
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Affiliation(s)
- Ayush Saxena
- Lignocellulose & Biofuel Laboratory, Department of Biosciences, Integral University, Lucknow 226026, Uttar Pradesh, India.
| | - Akhtar Hussain
- Lignocellulose & Biofuel Laboratory, Department of Biosciences, Integral University, Lucknow 226026, Uttar Pradesh, India.
| | - Fouziya Parveen
- Lignocellulose & Biofuel Laboratory, Department of Biosciences, Integral University, Lucknow 226026, Uttar Pradesh, India.
| | - Mohammad Ashfaque
- Lignocellulose & Biofuel Laboratory, Department of Biosciences, Integral University, Lucknow 226026, Uttar Pradesh, India.
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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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Lee H, Jung Sohn Y, Jeon S, Yang H, Son J, Jin Kim Y, Jae Park S. Sugarcane wastes as microbial feedstocks: A review of the biorefinery framework from resource recovery to production of value-added products. BIORESOURCE TECHNOLOGY 2023; 376:128879. [PMID: 36921642 DOI: 10.1016/j.biortech.2023.128879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 03/07/2023] [Accepted: 03/09/2023] [Indexed: 06/18/2023]
Abstract
Sugarcane industry is a major agricultural sector capable of producing sugars with byproducts including straw, bagasse, and molasses. Sugarcane byproducts are no longer wastes since they can be converted into carbon-rich resources for biorefinery if pretreatment of these is well established. Considerable efforts have been devoted to effective pretreatment techniques for each sugarcane byproduct to supply feedstocks in microbial fermentation to produce value-added fuels, chemicals, and polymers. These value-added chains, which start with low-value industrial wastes and end with high-value products, can make sugarcane-based biorefinery a more viable option for the modern chemical industry. In this review, recent advances in sugarcane valorization techniques are presented, ranging from sugarcane processing, pretreatment, and microbial production of value-added products. Three lucrative products, ethanol, 2,3-butanediol, and polyhydroxyalkanoates, whose production from sugarcane wastes has been widely researched, are being explored. Future studies and development in sugarcane waste biorefinery are discussed to overcome the challenges remaining.
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Affiliation(s)
- Haeyoung Lee
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Yu Jung Sohn
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Subeen Jeon
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Hyoju Yang
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - 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
| | - Yu Jin Kim
- 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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Tang Y, Wang Y, Yang Q, Zhang Y, Wu Y, Yang Y, Mei M, He M, Wang X, Yang S. Molecular mechanism of enhanced ethanol tolerance associated with hfq overexpression in Zymomonas mobilis. Front Bioeng Biotechnol 2022; 10:1098021. [PMID: 36588936 PMCID: PMC9797736 DOI: 10.3389/fbioe.2022.1098021] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 12/01/2022] [Indexed: 12/23/2022] Open
Abstract
Zymomonas mobilis is a promising microorganism for industrial bioethanol production. However, ethanol produced during fermentation is toxic to Z. mobilis and affects its growth and bioethanol production. Although several reports demonstrated that the RNA-binding protein Hfq in Z. mobilis contributes to the tolerance against multiple lignocellulosic hydrolysate inhibitors, the role of Hfq on ethanol tolerance has not been investigated. In this study, hfq in Z. mobilis was either deleted or overexpressed and their effects on cell growth and ethanol tolerance were examined. Our results demonstrated that hfq overexpression improved ethanol tolerance of Z. mobilis, which is probably due to energy saving by downregulating flagellar biosynthesis and heat stress response proteins, as well as reducing the reactive oxygen species induced by ethanol stress via upregulating the sulfate assimilation and cysteine biosynthesis. To explore proteins potentially interacted with Hfq, the TEV protease mediated Yeast Endoplasmic Reticulum Sequestration Screening system (YESS) was established in Z. mobilis. YESS results suggested that Hfq may modulate the cytoplasmic heat shock response by interacting with the heat shock proteins DnaK and DnaJ to deal with the ethanol inhibition. This study thus not only revealed the underlying mechanism of enhanced ethanol tolerance by hfq overexpression, but also provided an alternative approach to investigate protein-protein interactions in Z. mobilis.
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Affiliation(s)
- 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, China
| | - Yi Wang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province and School of Life Sciences, Hubei University, Wuhan, China
| | - 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, China
| | - Youpeng Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province and School of Life Sciences, Hubei University, Wuhan, China
| | - Yalun Wu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province and School of Life Sciences, Hubei University, Wuhan, 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, China
| | - Meng Mei
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province and School of Life Sciences, Hubei University, Wuhan, China
| | - Mingxiong He
- Key Laboratory of Development and Application of Rural Renewable Energy, Biomass Energy Technology Research Centre, Biogas Institute of Ministry of Agriculture, Ministry of Agriculture, Chengdu, 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, China,*Correspondence: Xia Wang, ; Shihui Yang,
| | - 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, China,*Correspondence: Xia Wang, ; Shihui Yang,
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Joshi A, Verma KK, D Rajput V, Minkina T, Arora J. Recent advances in metabolic engineering of microorganisms for advancing lignocellulose-derived biofuels. Bioengineered 2022; 13:8135-8163. [PMID: 35297313 PMCID: PMC9161965 DOI: 10.1080/21655979.2022.2051856] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Combating climate change and ensuring energy supply to a rapidly growing global population has highlighted the need to replace petroleum fuels with clean, and sustainable renewable fuels. Biofuels offer a solution to safeguard energy security with reduced ecological footprint and process economics. Over the past years, lignocellulosic biomass has become the most preferred raw material for the production of biofuels, such as fuel, alcohol, biodiesel, and biohydrogen. However, the cost-effective conversion of lignocellulose into biofuels remains an unsolved challenge at the industrial scale. Recently, intensive efforts have been made in lignocellulose feedstock and microbial engineering to address this problem. By improving the biological pathways leading to the polysaccharide, lignin, and lipid biosynthesis, limited success has been achieved, and still needs to improve sustainable biofuel production. Impressive success is being achieved by the retouring metabolic pathways of different microbial hosts. Several robust phenotypes, mostly from bacteria and yeast domains, have been successfully constructed with improved substrate spectrum, product yield and sturdiness against hydrolysate toxins. Cyanobacteria is also being explored for metabolic advancement in recent years, however, it also remained underdeveloped to generate commercialized biofuels. The bacterium Escherichia coli and yeast Saccharomyces cerevisiae strains are also being engineered to have cell surfaces displaying hydrolytic enzymes, which holds much promise for near-term scale-up and biorefinery use. Looking forward, future advances to achieve economically feasible production of lignocellulosic-based biofuels with special focus on designing more efficient metabolic pathways coupled with screening, and engineering of novel enzymes.
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Affiliation(s)
- Abhishek Joshi
- Laboratory of Biomolecular Technology, Department of Botany, Mohanlal Sukhadia University, Udaipur313001, India
| | - Krishan K. Verma
- Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs/Guangxi Key Laboratory of Sugarcane Genetic improvement/Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning - 530007, China
| | - Vishnu D Rajput
- Academy of Biology and Biotechnology, Southern Federal University, 344090, Russia
| | - Tatiana Minkina
- Academy of Biology and Biotechnology, Southern Federal University, 344090, Russia
| | - Jaya Arora
- Laboratory of Biomolecular Technology, Department of Botany, Mohanlal Sukhadia University, Udaipur313001, India,CONTACT Jaya Arora Laboratory of Biomolecular Technology, Department of Botany, Mohanlal Sukhadia University, Udaipur313001, India
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7
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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: 5] [Impact Index Per Article: 2.5] [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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8
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Braga A, Gomes D, Rainha J, Amorim C, Cardoso BB, Gudiña EJ, Silvério SC, Rodrigues JL, Rodrigues LR. Zymomonas mobilis as an emerging biotechnological chassis for the production of industrially relevant compounds. BIORESOUR BIOPROCESS 2021; 8:128. [PMID: 38650193 PMCID: PMC10992037 DOI: 10.1186/s40643-021-00483-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 12/06/2021] [Indexed: 11/10/2022] Open
Abstract
Zymomonas mobilis is a well-recognized ethanologenic bacterium with outstanding characteristics which make it a promising platform for the biotechnological production of relevant building blocks and fine chemicals compounds. In the last years, research has been focused on the physiological, genetic, and metabolic engineering strategies aiming at expanding Z. mobilis ability to metabolize lignocellulosic substrates toward biofuel production. With the expansion of the Z. mobilis molecular and computational modeling toolbox, the potential of this bacterium as a cell factory has been thoroughly explored. The number of genomic, transcriptomic, proteomic, and fluxomic data that is becoming available for this bacterium has increased. For this reason, in the forthcoming years, systems biology is expected to continue driving the improvement of Z. mobilis for current and emergent biotechnological applications. While the existing molecular toolbox allowed the creation of stable Z. mobilis strains with improved traits for pinpointed biotechnological applications, the development of new and more flexible tools is crucial to boost the engineering capabilities of this bacterium. Novel genetic toolkits based on the CRISPR-Cas9 system and recombineering have been recently used for the metabolic engineering of Z. mobilis. However, they are mostly at the proof-of-concept stage and need to be further improved.
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Affiliation(s)
- Adelaide Braga
- CEB-Centre of Biological Engineering, Universidade Do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Daniela Gomes
- CEB-Centre of Biological Engineering, Universidade Do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - João Rainha
- CEB-Centre of Biological Engineering, Universidade Do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Cláudia Amorim
- CEB-Centre of Biological Engineering, Universidade Do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Beatriz B Cardoso
- CEB-Centre of Biological Engineering, Universidade Do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Eduardo J Gudiña
- CEB-Centre of Biological Engineering, Universidade Do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Sara C Silvério
- CEB-Centre of Biological Engineering, Universidade Do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Joana L Rodrigues
- CEB-Centre of Biological Engineering, Universidade Do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Lígia R Rodrigues
- CEB-Centre of Biological Engineering, Universidade Do Minho, Campus de Gualtar, 4710-057, Braga, Portugal.
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9
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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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10
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Zhao P, Tian P. Biosynthesis pathways and strategies for improving 3-hydroxypropionic acid production in bacteria. World J Microbiol Biotechnol 2021; 37:117. [PMID: 34128152 DOI: 10.1007/s11274-021-03091-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 06/08/2021] [Indexed: 12/01/2022]
Abstract
3-Hydroxypropionic acid (3-HP) represents an economically important platform compound from which a panel of bulk chemicals can be derived. Compared with petroleum-dependent chemical synthesis, bioproduction of 3-HP has attracted more attention due to utilization of renewable biomass. This review outlines bacterial production of 3-HP, covering aspects of host strains (e.g., Escherichia coli and Klebsiella pneumoniae), metabolic pathways, key enzymes, and hurdles hindering high-level production. Inspired by the state-of-the-art advances in metabolic engineering and synthetic biology, we come up with protocols to overcome the hurdles constraining 3-HP production. The protocols range from rewiring of metabolic networks, alleviation of metabolite toxicity, to dynamic control of cell size and density. Especially, this review highlights the substantial contribution of microbial growth to 3-HP production, as we recognize the synchronization between cell growth and 3-HP formation. Accordingly, we summarize the following growth-promoting strategies: (i) optimization of fermentation conditions; (ii) construction of gene circuits to alleviate feedback inhibition; (iii) recruitment of RNA polymerases to overexpress key enzymes which in turn boost cell growth and 3-HP production. Lastly, we propose metabolic engineering approaches to simplify downstream separation and purification. Overall, this review aims to portray a picture of bacterial production of 3-HP.
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Affiliation(s)
- Peng Zhao
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China
| | - Pingfang Tian
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China.
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Yi X, Mei J, Lin L, Wang W. Overexpression of Dioxygenase Encoding Gene Accelerates the Phenolic Aldehyde Conversion and Ethanol Fermentability of Zymomonas mobilis. Appl Biochem Biotechnol 2021; 193:3017-3027. [PMID: 33826067 DOI: 10.1007/s12010-021-03551-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 03/22/2021] [Indexed: 11/27/2022]
Abstract
NADH-dependent reductase enzyme catalyzes the phenolic aldehyde conversion and correspondingly improves the ethanol fermentability of the ethanologenic Zymomonas mobilis. This study constructed the transcriptional landscape of mono/dioxygenase genes in Z. mobilis ZM4 under the stress of the toxic phenolic aldehyde inhibitors of 4-hydroxybenzaldehyde, syringaldehyde, and vanillin. One specific dioxygenase encoding gene ZMO1721 was differentially expressed by 3.07-folds under the stress of 4-hydroxybenzaldehyde among the eleven mono/dioxygenase genes. The purified ZMO1721 shared 99.9% confidence and 48.0% identity with the oxidoreductase in Rhodoferax ferrireducens T118 was assayed and the NADH-dependent reduction activity was confirmed for phenolic aldehyde vanillin conversion. The ZMO1721 gene was then overexpressed in Z. mobilis ZM4 and the 4-hydroxybenzaldehyde conversion rate was accelerated. The cell growth, glucose consumption, and ethanol productivity of Z. mobilis ZM4 were also improved by ZMO1721 overexpression. The genes identified on improving phenolic aldehyde tolerance and ethanol fermentability in this study could be used as the synthetic biology tools for modification of ethanologenic strains.
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Affiliation(s)
- Xia Yi
- Jiangxi Provincial Key Laboratory of Systems Biomedicine, Jiujiang University, 17 Lufeng Road, Jiujiang, 332000, China.
| | - Jun Mei
- Jiangxi Provincial Key Laboratory of Systems Biomedicine, Jiujiang University, 17 Lufeng Road, Jiujiang, 332000, China
| | - Ling Lin
- Jiangxi Provincial Key Laboratory of Systems Biomedicine, Jiujiang University, 17 Lufeng Road, Jiujiang, 332000, China
| | - Wei Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
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