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Penneru SK, Saharay M, Krishnan M. CelS-Catalyzed Processive Cellulose Degradation and Cellobiose Extraction for the Production of Bioethanol. J Chem Inf Model 2022; 62:6628-6638. [PMID: 35649216 DOI: 10.1021/acs.jcim.2c00239] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Bacterial cellulase enzymes are potent candidates for the efficient production of bioethanol, a promising alternative to fossil fuels, from cellulosic biomass. These enzymes catalyze the breakdown of cellulose in plant biomass into simple sugars and then to bioethanol. In the absence of the enzyme, the cellulosic biomass is recalcitrant to decomposition due to fermentation-resistant lignin and pectin coatings on the cellulose surface, which make them inaccessible for hydrolysis. Cellobiohydrolase CelS is a microbial enzyme that binds to cellulose fiber and efficiently cleaves it into a simple sugar (cellobiose) by a repeated processive chopping mechanism. The two contributing factors to the catalytic reaction rate and the yield of cellobiose are the efficient product expulsion from the product binding site of CelS and the movement of the substrate or cellulose chain into the active site. Despite progress in understanding product expulsion in other cellulases, much remains to be understood about the molecular mechanism of processive action of these enzymes. Here, nonequilibrium molecular dynamics simulations using suitable reaction coordinates are carried out to investigate the energetics and mechanism of the substrate dynamics and product expulsion in CelS. The calculated free energy barrier for the product expulsion is three times lower than that for the processive action indicating that product removal is relatively easier and faster than the sliding of the substrate to the catalytic active site. The water traffic near the active site in response to the product expulsion and the processive action is also explored.
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Affiliation(s)
- Sree Kavya Penneru
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, 1311 Cumberland Avenue, Knoxville, Tennessee 37996-1939, United States
| | - Moumita Saharay
- Department of Systems and Computational Biology, School of Life Sciences, University of Hyderabad, Prof. C. R. Rao Road, Gachibowli, Hyderabad 500046, Telangana, India
| | - Marimuthu Krishnan
- Center for Computational Natural Sciences and Bioinformatics (CCNSB), International Institute of Information Technology, Gachibowli, Hyderabad 500032, India
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Althuri A, Venkata Mohan S. Emerging innovations for sustainable production of bioethanol and other mercantile products from circular economy perspective. BIORESOURCE TECHNOLOGY 2022; 363:128013. [PMID: 36155807 DOI: 10.1016/j.biortech.2022.128013] [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: 08/04/2022] [Revised: 09/16/2022] [Accepted: 09/17/2022] [Indexed: 06/16/2023]
Abstract
Biogenic municipal solid waste (BMSW) and food waste (FW) with high energy density are ready to tap renewable resources for industrial scale ethanol refinery foreseen for establishing bio-based society. Circular economy has occupied limelight in the domain of renewable energy and sustainable chemicals production. The present review highlights the importance of BMSW/FW as newer feed reserves that can cater as parent molecules for an array of high-visibility industrial products along with bioethanol upon implementing a judicious closed-cascade mass-flow mechanism enabling ultimate feed and waste stream valorisation. Though these organics are attractive resources their true potential for energy production has not been quantified yet owing to their heterogeneous composition and associated technical challenges thus pushing waste refinery and industrial symbiosis concepts to backseat. To accelerate this industrial vision, the novel bioprocessing strategies for enhanced and low-cost production of bioethanol from BMSW/FW along with other commercially imperative product portfolio have been discussed.
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Affiliation(s)
- Avanthi Althuri
- Bioengineering and Environmental Sciences Lab, Department of Energy and Environmental Engineering, CSIR-Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500007, Telangana, India; Department of Biotechnology, Indian Institute of Technology Hyderabad, Kandi, Sangareddy-502284, Telangana, India
| | - S Venkata Mohan
- Bioengineering and Environmental Sciences Lab, Department of Energy and Environmental Engineering, CSIR-Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500007, Telangana, India.
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3
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Xylose Fermentation Was Improved by Kluyveromyces marxianus KHM89 through Up-regulation of Nicotinamide Adenine Dinucleotide (NAD+) Salvage Pathway. BIOTECHNOL BIOPROC E 2022. [DOI: 10.1007/s12257-022-0036-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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4
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Shang C, Li Y, Zhang J, Gan S. Analysis of Bacterial Diversity in Different Types of Daqu and Fermented Grains From Danquan Distillery. Front Microbiol 2022; 13:883122. [PMID: 35865918 PMCID: PMC9295720 DOI: 10.3389/fmicb.2022.883122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 06/07/2022] [Indexed: 11/13/2022] Open
Abstract
Bacterial communities in high-temperature Daqu and fermented grains are important for brewing Jiang-flavor Baijiu such as Danquan Baijiu. Daqu is a saccharifying and fermenting agent, which has a significant impact on the flavor of Baijiu. However, bacterial communities in three different types of samples from the Danquan distillery (dqjq_ck, dqjqcp, and dqjp3) were still unclear, which limited further development of Danquan Baijiu. “dqjq_ck” and “dqjqcp” indicate high-temperature Daqu at days 45 and 135, respectively. “dqjp3” indicates fermented grains. In this study, the bacterial communities of three samples were analyzed by Illumina Miseq high-throughput sequencing. The bacterial communities of three samples primarily composed of thermophilic bacteria and bacteria with stress resistance. The most abundant species in dqjq_ck, dqjqcp, and dqjp3 were Comamonas, Bacillus, and unclassified Lactobacillales, respectively. The main bacteria included Bacillus, Comamonas, Myroides, Paenibacillus, Acetobacter, Kroppenstedtia, Staphylococcus, Saccharopolyspora, Planifilum, Lactobacillus, Acinetobacter, Oceanobacillus, Enterococcus, Thermoactinomyces, Lactococcus, Streptomyces, Saccharomonospora, Tepidimicrobium, Anaerosalibacter, unclassified_Lactobacillales, unclassified_Thermoactinomycetaceae_1, unclassified_Bacillaceae_2, unclassified_Bacillales, unclassified_Microbacteriaceae, unclassified_Rhodobacteraceae, unclassified_Actinopolysporineae, and unclassified_Flavobacteriaceae in three samples (percentage was more than 1% in one of three samples). In our study, the succession of microbiota in three samples representing three important stages of Danquan Baijiu brewing was revealed. This article lays a good foundation for understanding the fermentation mechanism and screening some excellent indigenous bacteria to improve the quality of Danquan Baijiu in future.
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Affiliation(s)
- Changhua Shang
- College of Life Sciences, Guangxi Normal University, Guilin, China
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guilin, China
- Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin (Guangxi Normal University), Guilin, China
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
- *Correspondence: Changhua Shang
| | - Yujia Li
- College of Life Sciences, Guangxi Normal University, Guilin, China
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guilin, China
| | - Jin Zhang
- College of Life Sciences, Guangxi Normal University, Guilin, China
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guilin, China
| | - Shanling Gan
- College of Life Sciences, Guangxi Normal University, Guilin, China
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guilin, China
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5
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Vamsi Krishna K, Bharathi N, George Shiju S, Alagesan Paari K, Malaviya A. An updated review on advancement in fermentative production strategies for biobutanol using Clostridium spp. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:47988-48019. [PMID: 35562606 DOI: 10.1007/s11356-022-20637-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Accepted: 04/30/2022] [Indexed: 06/15/2023]
Abstract
A significant concern of our fuel-dependent era is the unceasing exhaustion of petroleum fuel supplies. In parallel to this, environmental issues such as the greenhouse effect, change in global climate, and increasing global temperature must be addressed on a priority basis. Biobutanol, which has fuel characteristics comparable to gasoline, has attracted global attention as a viable green fuel alternative among the many biofuel alternatives. Renewable biomass could be used for the sustainable production of biobutanol by the acetone-butanol-ethanol (ABE) pathway. Non-extinguishable resources, such as algal and lignocellulosic biomass, and starch are some of the most commonly used feedstock for fermentative production of biobutanol, and each has its particular set of advantages. Clostridium, a gram-positive endospore-forming bacterium that can produce a range of compounds, along with n-butanol is traditionally known for its biobutanol production capabilities. Clostridium fermentation produces biobased n-butanol through ABE fermentation. However, low butanol titer, a lack of suitable feedstock, and product inhibition are the primary difficulties in biobutanol synthesis. Critical issues that are essential for sustainable production of biobutanol include (i) developing high butanol titer producing strains utilizing genetic and metabolic engineering approaches, (ii) renewable biomass that could be used for biobutanol production at a larger scale, and (iii) addressing the limits of traditional batch fermentation by integrated bioprocessing technologies with effective product recovery procedures that have increased the efficiency of biobutanol synthesis. Our paper reviews the current progress in all three aspects of butanol production and presents recent data on current practices in fermentative biobutanol production technology.
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Affiliation(s)
- Kondapalli Vamsi Krishna
- Applied and Industrial Biotechnology Laboratory, CHRIST (Deemed-to-Be University), Hosur road, Bangalore, Karnataka, India
| | - Natarajan Bharathi
- Department of Life Sciences, CHRIST (Deemed to Be University), Bengaluru, India
| | - Shon George Shiju
- Applied and Industrial Biotechnology Laboratory, CHRIST (Deemed-to-Be University), Hosur road, Bangalore, Karnataka, India
| | | | - Alok Malaviya
- Applied and Industrial Biotechnology Laboratory, CHRIST (Deemed-to-Be University), Hosur road, Bangalore, Karnataka, India.
- Department of Life Sciences, CHRIST (Deemed to Be University), Bengaluru, India.
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Kazemi Shariat Panahi H, Dehhaghi M, Dehhaghi S, Guillemin GJ, Lam SS, Aghbashlo M, Tabatabaei M. Engineered bacteria for valorizing lignocellulosic biomass into bioethanol. BIORESOURCE TECHNOLOGY 2022; 344:126212. [PMID: 34715341 DOI: 10.1016/j.biortech.2021.126212] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/17/2021] [Accepted: 10/20/2021] [Indexed: 06/13/2023]
Abstract
Appropriate bioprocessing of lignocellulosic materials into ethanol could address the world's insatiable appetite for energy while mitigating greenhouse gases. Bioethanol is an ideal gasoline extender and is widely used in many countries in blended form with gasoline at specific ratios to improve fuel characteristics and engine performance. Although the bioethanol production industry has long been operational, finding a suitable microbial agent for the efficient conversion of lignocelluloses is still an active field of study. Among available microbial candidates, engineered bacteria may be promising ethanol producers while may show other desired traits such as thermophilic nature and high ethanol tolerance. This review provides the current knowledge on the introduction, overexpression, and deletion of the genes that have been performed in bacterial hosts to achieve higher ethanol yield, production rate and titer, and tolerance. The constraints and possible solutions and economic feasibility of the processes utilizing such engineered strains are also discussed.
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Affiliation(s)
- Hamed Kazemi Shariat Panahi
- Henan Province Engineering Research Center for Forest Biomass Value-added Products, School of Forestry, Henan Agricultural University, Zhengzhou, Henan, 450002, China; Neuroinflammation Group, Department of Biomedical Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, NSW, Australia; Biofuel Research Team (BRTeam), Terengganu, Malaysia
| | - Mona Dehhaghi
- Neuroinflammation Group, Department of Biomedical Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, NSW, Australia; Biofuel Research Team (BRTeam), Terengganu, Malaysia; PANDIS.org, Australia
| | - Somayeh Dehhaghi
- Department of Agricultural Extension and Education, Tarbiat Modares University, Tehran 14115-336, Iran
| | - Gilles J Guillemin
- Neuroinflammation Group, Department of Biomedical Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, NSW, Australia; PANDIS.org, Australia
| | - Su Shiung Lam
- Henan Province Engineering Research Center for Forest Biomass Value-added Products, School of Forestry, Henan Agricultural University, Zhengzhou, Henan, 450002, China; Higher Institution Centre of Excellence (HICoE), Institute of Tropical Aquaculture and Fisheries (AKUATROP), Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia.
| | - Mortaza Aghbashlo
- Department of Mechanical Engineering of Agricultural Machinery, Faculty of Agricultural Engineering and Technology, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran
| | - Meisam Tabatabaei
- Henan Province Engineering Research Center for Forest Biomass Value-added Products, School of Forestry, Henan Agricultural University, Zhengzhou, Henan, 450002, China; Biofuel Research Team (BRTeam), Terengganu, Malaysia; Higher Institution Centre of Excellence (HICoE), Institute of Tropical Aquaculture and Fisheries (AKUATROP), Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia; Microbial Biotechnology Department, Agricultural Biotechnology Research Institute of Iran (ABRII), Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
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7
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8
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Sohn YJ, Son J, Jo SY, Park SY, Yoo JI, Baritugo KA, Na JG, Choi JI, Kim HT, Joo JC, Park SJ. Chemoautotroph Cupriavidus necator as a potential game-changer for global warming and plastic waste problem: A review. BIORESOURCE TECHNOLOGY 2021; 340:125693. [PMID: 34365298 DOI: 10.1016/j.biortech.2021.125693] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/26/2021] [Accepted: 07/27/2021] [Indexed: 06/13/2023]
Abstract
Cupriavidus necator, a versatile microorganism found in both soil and water, can have both heterotrophic and lithoautotrophic metabolisms depending on environmental conditions. C. necator has been extensively examined for producing Polyhydroxyalkanoates (PHAs), the promising polyester alternatives to petroleum-based synthetic polymers because it has a superior ability for accumulating a considerable amount of PHAs from renewable resources. The development of metabolically engineered C. necator strains has led to their application for synthesizing biopolymers, biofuels and biochemicals such as ethanol, isobutanol and higher alcohols. Bio-based processes of recombinant C. necator have made much progress in production of these high-value products from biomass wastes, plastic wastes and even waste gases. In this review, we discuss the potential of C. necator as promising platform host strains that provide a great opportunity for developing a waste-based circular bioeconomy.
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Affiliation(s)
- 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
| | - 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
| | - Seo Young Jo
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Se Young Park
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Jee In Yoo
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Kei-Anne Baritugo
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Jeong Geol Na
- Department of Chemical and Biomolecular Engineering, Sogang University, Seoul, Republic of Korea.
| | - Jong-Il Choi
- Department of Biotechnology and Bioengineering, Chonnam National University, Gwangju 61186, Korea.
| | - Hee Taek Kim
- Department of Food Science and Technology, College of Agriculture and Life Sciences, Chungnam National University, Daejeon 34134, Republic of Korea.
| | - Jeong Chan Joo
- Department of Biotechnology, The Catholic University of Korea, Gyeonggi-do, 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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Li S, Wang L, Wang N, Cong W. Combining Genome Shuffling with Streptomycin Resistance to Improve Poly-γ-L-diaminobutanoic Acid Production in Bacillus pumilus. BIOTECHNOL BIOPROC E 2021. [DOI: 10.1007/s12257-020-0320-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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10
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Lee JY, Cha S, Lee JH, Lim HG, Noh MH, Kang CW, Jung GY. Plug-in repressor library for precise regulation of metabolic flux in Escherichia coli. Metab Eng 2021; 67:365-372. [PMID: 34333137 DOI: 10.1016/j.ymben.2021.07.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 07/10/2021] [Accepted: 07/28/2021] [Indexed: 10/20/2022]
Abstract
In metabolic engineering, enhanced production of value-added chemicals requires precise flux control between growth-essential competing and production pathways. Although advances in synthetic biology have facilitated the exploitation of a number of genetic elements for precise flux control, their use requires expensive inducers, or more importantly, needs complex and time-consuming processes to design and optimize appropriate regulator components, case-by-case. To overcome this issue, we devised the plug-in repressor libraries for target-specific flux control, in which expression levels of the repressors were diversified using degenerate 5' untranslated region (5' UTR) sequences employing the UTR Library Designer. After we validated a wide expression range of the repressor libraries, they were applied to improve the production of lycopene from glucose and 3-hydroxypropionic acid (3-HP) from acetate in Escherichia coli via precise flux rebalancing to enlarge precursor pools. Consequently, we successfully achieved optimal carbon fluxes around the precursor nodes for efficient production. The most optimized strains were observed to produce 2.59 g/L of 3-HP and 11.66 mg/L of lycopene, which were improved 16.5-fold and 2.82-fold, respectively, compared to those produced by the parental strains. These results indicate that carbon flux rebalancing using the plug-in library is a powerful strategy for efficient production of value-added chemicals in E. coli.
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Affiliation(s)
- Ji Yeon Lee
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk, 37673, South Korea
| | - Sanghak Cha
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk, 37673, South Korea
| | - Ji Hoon Lee
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk, 37673, South Korea
| | - Hyun Gyu Lim
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk, 37673, South Korea
| | - Myung Hyun Noh
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk, 37673, South Korea
| | - Chae Won Kang
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk, 37673, South Korea
| | - Gyoo Yeol Jung
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk, 37673, South Korea; Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk, 37673, South Korea.
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11
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Maleki F, Changizian M, Zolfaghari N, Rajaei S, Noghabi KA, Zahiri HS. Consolidated bioprocessing for bioethanol production by metabolically engineered Bacillus subtilis strains. Sci Rep 2021; 11:13731. [PMID: 34215768 PMCID: PMC8253836 DOI: 10.1038/s41598-021-92627-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 06/14/2021] [Indexed: 11/12/2022] Open
Abstract
Bioethanol produced by fermentative microorganisms is regarded as an alternative to fossil fuel. Bioethanol to be used as a viable energy source must be produced cost-effectively by removing expense-intensive steps such as the enzymatic hydrolysis of substrate. Consolidated bioprocessing (CBP) is believed to be a practical solution combining saccharification and fermentation in a single step catalyzed by a microorganism. Bacillus subtills with innate ability to grow on a diversity of carbohydrates seems promising for affordable CBP bioethanol production using renewable plant biomass and wastes. In this study, the genes encoding alcohol dehydrogenase from Z. mobilis (adhZ) and S. cerevisiae (adhS) were each used with Z. mobilis pyruvate decarboxylase gene (pdcZ) to create ethanologenic operons in a lactate-deficient (Δldh) B. subtilis resulting in NZ and NZS strains, respectively. The S. cerevisiae adhS caused significantly more ethanol production by NZS and therefore was used to make two other operons including one with double copies of both pdcZ and adhS and the other with a single pdcZ but double adhS genes expressed in N(ZS)2 and NZS2 strains, respectively. In addition, two fusion genes were constructed with pdcZ and adhS in alternate orientations and used for ethanol production by the harboring strains namely NZ:S and NS:Z, respectively. While the increase of gene dosage was not associated with elevated carbon flow for ethanol production, the fusion gene adhS:pdcZ resulted in a more than two times increase of productivity by strain NS:Z as compared with NZS during 48 h fermentation. The CBP ethanol production by NZS and NS:Z using potatoes resulted in 16.3 g/L and 21.5 g/L ethanol during 96 h fermentation, respectively. For the first time in this study, B. subtilis was successfully used for CBP ethanol production with S. cerevisiae alcohol dehydrogenase. The results of the study provide insights on the potentials of B. subtilis for affordable bioethanol production from inexpensive plant biomass and wastes. However, the potentials need to be improved by metabolic and process engineering for higher yields of ethanol production and plant biomass utilization.
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Affiliation(s)
- Fatemeh Maleki
- Department of Energy and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
| | - Mohammad Changizian
- Department of Energy and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
| | - Narges Zolfaghari
- Department of Energy and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
| | - Sarah Rajaei
- Department of Energy and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
| | - Kambiz Akbari Noghabi
- Department of Energy and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
| | - Hossein Shahbani Zahiri
- Department of Energy and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran.
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12
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Molecular cloning, characterisation and expression of a gene encoding cellobiose dehydrogenase from Termitomyces clypeatus. GENE REPORTS 2021. [DOI: 10.1016/j.genrep.2021.101063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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13
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Improved Sugar Recovery from Orange Peel by Statistical Optimization of Thermo-Alkaline Pretreatment. Processes (Basel) 2021. [DOI: 10.3390/pr9030409] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Orange peel, which is a by-product of oranges, contains carbohydrates that can be converted into sugars and used in the fermentation process. In this study, the thermal alkaline pretreatment process was chosen because of its simplicity and lesser reaction time. In addition, the reaction factors were optimized using response surface methodology. The determined optimal conditions were as follows: 60.1 g/L orange peels loading, 3% KOH and 30 min. Under the optimal conditions, glucan content (GC) and enzymatic digestibility (ED) were found to be 32.8% and 87.8%, respectively. Enzymatic hydrolysis was performed with pretreated and non-pretreated orange peels using three types of enzyme complex (cellulase, cellobiase and xylanase). The minimum concentrations of enzyme complex required to obtain maximum ED were 30 FPU (filter paper unit), 15 CBU (cellobiase unit), and 30 XNU (xylanase unit) based on 1 g-biomass. Additionally, ED of the treated group was approximately 3.7-fold higher than that of the control group. In conclusion, the use of orange peel as a feedstock for biorefinery can be a strategic solution to reduce wastage of resources and produce sustainable bioproducts.
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14
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Improved Glucose Recovery from Sicyos angulatus by NaOH Pretreatment and Application to Bioethanol Production. Processes (Basel) 2021. [DOI: 10.3390/pr9020245] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
As greenhouse gases and environmental pollution become serious, the demand for alternative energy such as bioethanol has rapidly increased, and a large supply of biomass is required for bioenergy production. Lignocellulosic biomass is the most abundant on the planet and a large part of it, the second-generation biomass, has the advantage of not being a food resource. In this study, Sicyos angulatus, known as an invasive plant (harmful) species, was used as a raw material for bioethanol production. In order to improve enzymatic hydrolysis, S. angulatus was pretreated with different NaOH concentration at 121 °C for 10 min. The optimal NaOH concentration for the pretreatment was determined to be 2% (w/w), and the glucan content (GC) and enzymatic digestibility (ED) were 46.7% and 55.3%, respectively. Through NaOH pretreatment, the GC and ED of S. angulatus were improved by 2.4-fold and 2.5-fold, respectively, compared to the control (untreated S. angulatus). The hydrolysates from S. angulatus were applied to a medium for bioethanol fermentation of Saccharomyces cerevisiae K35. Finally, the maximum ethanol production was found to be 41.3 g based on 1000 g S. angulatus, which was 2.4-fold improved than the control group.
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Khang TU, Kim MJ, Yoo JI, Sohn YJ, Jeon SG, Park SJ, Na JG. Rapid analysis of polyhydroxyalkanoate contents and its monomer compositions by pyrolysis-gas chromatography combined with mass spectrometry (Py-GC/MS). Int J Biol Macromol 2021; 174:449-456. [PMID: 33485890 DOI: 10.1016/j.ijbiomac.2021.01.108] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 01/12/2021] [Accepted: 01/16/2021] [Indexed: 12/19/2022]
Abstract
Here, we report an analysis method for determining PHA (polyhydroxyalkanoates) contents and their monomer composition in microbial cells based on pyrolysis gas chromatography combined with mass spectrometry (Py-GC/MS). Various kinds of microbial cells accumulating different PHA contents and monomer compositions were prepared through the cultivation of Ralstonia eutropha and recombinant Escherichia coli. Py-GC/MS could analyse these samples in a short time without complicated pretreatment steps. Characteristic peaks such as 2-butenoic acid, 2-pentenoic acid, and hexadecanoic acid regarding PHA compositions and cell components were identified. Considering constituents of cells and ratios of peak areas of dehydrated monomers to hexadecanoic acid, a simple equation for estimation of PHA contents in microbial cells was derived. Also, monomer compositions of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) in R. eutropha could be successfully determined based on peak area of 2-butenoic acid and 2-pentenoic acid of Py-GC/MS, which are the corresponding species of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) in PHBV. Correlation of results between GC-FID and Py-GC/MS could be fitted very well. This method shows similar results for the samples obtained from same experimental conditions, allowing rapid and reliable analysis. Py-GC/MS can be a promising tool to rapidly screen PHA-positive strains based on polymer contents along with monomer compositions.
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Affiliation(s)
- Tae Uk Khang
- Department of Chemical and Biomolecular Engineering, Sogang University, Seoul 04107, Republic of Korea
| | - Min-Jae Kim
- Korea Institute of Energy Research, 152 Gajeong-ro, Yuseong-gu, Daejeon 34129, Republic of Korea.
| | - Jee In Yoo
- Division of Chemical Engineering and Materials Science, System Health & Engineering Major in Graduate School (BK21 Plus Program), Ewha Womans University, Seoul 03760, Republic of Korea
| | - Yu Jung Sohn
- Division of Chemical Engineering and Materials Science, System Health & Engineering Major in Graduate School (BK21 Plus Program), Ewha Womans University, Seoul 03760, Republic of Korea
| | - Sang Goo Jeon
- Korea Institute of Energy Research, 152 Gajeong-ro, Yuseong-gu, Daejeon 34129, Republic of Korea.
| | - Si Jae Park
- Division of Chemical Engineering and Materials Science, System Health & Engineering Major in Graduate School (BK21 Plus Program), Ewha Womans University, Seoul 03760, Republic of Korea.
| | - Jeong-Geol Na
- Department of Chemical and Biomolecular Engineering, Sogang University, Seoul 04107, Republic of Korea.
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16
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Lu J, Li J, Gao H, Zhou D, Xu H, Cong Y, Zhang W, Xin F, Jiang M. Recent progress on bio-succinic acid production from lignocellulosic biomass. World J Microbiol Biotechnol 2021; 37:16. [PMID: 33394223 DOI: 10.1007/s11274-020-02979-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 12/05/2020] [Indexed: 11/28/2022]
Abstract
Succinic acid is a valuable bulk chemical, which has been extensively applied in food, medicine, surfactants and biodegradable plastics industries. As a substitute for chemical raw material, bio-based succinic acid production has received increasing attention due to the depletion of fossil fuels and environmental issues. Meanwhile, the effective bioconversion of lignocellulosic biomass has always been a hot spot of interest owning to the advantages of low expense, abundance and renewability. Consolidated bioprocessing (CBP) is considered to be an alternative approach with outstanding potential, as CBP can not only improve the product yield and productivity, but also reduce the equipment and operating costs. In addition, the current emerging microbial co-cultivation systems provide strong competitiveness for lignocellulose utilization through CBP. This article comprehensively discusses different strategies for the bioconversion of lignocellulose to succinic acid. Based on the principles and technical concepts of CBP, this review focuses on the progress of succinic acid production under different CBP strategies (metabolic engineering based and microbial co-cultivation based). Moreover, the main challenges faced by CBP-based succinic acid fermentation are analyzed, and the future direction of CBP production is prospected.
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Affiliation(s)
- Jiasheng Lu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211816, People's Republic of China
| | - Jiawen Li
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211816, People's Republic of China
| | - Hao Gao
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211816, People's Republic of China
| | - Dawei Zhou
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211816, People's Republic of China
| | - Huixin Xu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211816, People's Republic of China
| | - Yuexin Cong
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211816, People's Republic of China
| | - Wenming Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211816, People's Republic of China. .,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211816, People's Republic of China.
| | - Fengxue Xin
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211816, People's Republic of China. .,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211816, People's Republic of China.
| | - Min Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211816, People's Republic of China.,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211816, People's Republic of China
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17
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Kwon DH, Kim SB, Park, JB, Ha SJ. Overexpression of Mutant Galactose Permease ( ScGal2_N376F) Effective for Utilization of Glucose/Xylose or Glucose/ Galactose Mixture by Engineered Kluyveromyces marxianus. J Microbiol Biotechnol 2020; 30:1944-1949. [PMID: 33046681 PMCID: PMC9728301 DOI: 10.4014/jmb.2008.08035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/28/2020] [Accepted: 10/05/2020] [Indexed: 12/15/2022]
Abstract
Mutant sugar transporter ScGAL2-N376F was overexpressed in Kluyveromyces marxianus for efficient utilization of xylose, which is one of the main components of cellulosic biomass. K. marxianus ScGal2_N376F, the ScGAL2-N376F-overexpressing strain, exhibited 47.04 g/l of xylose consumption and 26.55 g/l of xylitol production, as compared to the parental strain (24.68 g/l and 7.03 g/l, respectively) when xylose was used as the sole carbon source. When a mixture of glucose and xylose was used as the carbon source, xylose consumption and xylitol production rates were improved by 195% and 360%, respectively, by K. marxianus ScGal2_N376F. Moreover, the glucose consumption rate was improved by 27% as compared to that in the parental strain. Overexpression of both wild-type ScGAL2 and mutant ScGAL2-N376F showed 48% and 52% enhanced sugar consumption and ethanol production rates, respectively, when a mixture of glucose and galactose was used as the carbon source, which is the main component of marine biomass. As shown in this study, ScGAL2-N376F overexpression can be applied for the efficient production of biofuels or biochemicals from cellulosic or marine biomass.
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Affiliation(s)
- Deok-Ho Kwon
- Department of Bioengineering and Technology, Kangwon National University, Chuncheon 2434, Republic of Korea,Interdisciplinary Program in Biohealth-Machinery Convergence Engineering, Kangwon National University, Chuncheon 2441, Republic of Korea
| | - Saet-Byeol Kim
- Department of Bioengineering and Technology, Kangwon National University, Chuncheon 2434, Republic of Korea
| | - Jae-Bum Park,
- Department of Bioengineering and Technology, Kangwon National University, Chuncheon 2434, Republic of Korea
| | - Suk-Jin Ha
- Department of Bioengineering and Technology, Kangwon National University, Chuncheon 2434, Republic of Korea,Institute of Fermentation and Brewing, Kangwon National University, Chuncheon 4341, Republic of Korea,Interdisciplinary Program in Biohealth-Machinery Convergence Engineering, Kangwon National University, Chuncheon 2441, Republic of Korea,Corresponding author Phone: +82-33-250-6278 Fax: +82-33-243-6350 E-mail:
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18
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19
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Kim D, Lee JW. Genetic Biocontainment Systems for the Safe Use of Engineered Microorganisms. BIOTECHNOL BIOPROC E 2020. [DOI: 10.1007/s12257-020-0070-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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20
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21
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Jeong D, Oh EJ, Ko JK, Nam JO, Park HS, Jin YS, Lee EJ, Kim SR. Metabolic engineering considerations for the heterologous expression of xylose-catabolic pathways in Saccharomyces cerevisiae. PLoS One 2020; 15:e0236294. [PMID: 32716960 PMCID: PMC7384654 DOI: 10.1371/journal.pone.0236294] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 07/01/2020] [Indexed: 11/18/2022] Open
Abstract
Xylose, the second most abundant sugar in lignocellulosic biomass hydrolysates, can be fermented by Saccharomyces cerevisiae expressing one of two heterologous xylose pathways: a xylose oxidoreductase pathway and a xylose isomerase pathway. Depending on the type of the pathway, its optimization strategies and the fermentation efficiencies vary significantly. In the present study, we constructed two isogenic strains expressing either the oxidoreductase pathway (XYL123) or the isomerase pathway (XI-XYL3), and delved into simple and reproducible ways to improve the resulting strains. First, the strains were subjected to the deletion of PHO13, overexpression of TAL1, and adaptive evolution, but those individual approaches were only effective in the XYL123 strain but not in the XI-XYL3 strain. Among other optimization strategies of the XI-XYL3 strain, we found that increasing the copy number of the xylose isomerase gene (xylA) is the most promising but yet preliminary strategy for the improvement. These results suggest that the oxidoreductase pathway might provide a simpler metabolic engineering strategy than the isomerase pathway for the development of efficient xylose-fermenting strains under the conditions tested in the present study.
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Affiliation(s)
- Deokyeol Jeong
- School of Food Science and Biotechnology, Kyungpook National University, Daegu, Republic of Korea
| | - Eun Joong Oh
- Renewable and Sustainable Energy Institute (RASEI), University of Colorado Boulder, Boulder, Colorado, United States of America
| | - Ja Kyong Ko
- Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
| | - Ju-Ock Nam
- School of Food Science and Biotechnology, Kyungpook National University, Daegu, Republic of Korea
| | - Hee-Soo Park
- School of Food Science and Biotechnology, Kyungpook National University, Daegu, Republic of Korea
| | - Yong-Su Jin
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Eun Jung Lee
- Department of Chemical Engineering, School of Applied Chemical Engineering, Kyungpook National University, Daegu, Republic of Korea
- * E-mail: (EJL); (SRK)
| | - Soo Rin Kim
- School of Food Science and Biotechnology, Kyungpook National University, Daegu, Republic of Korea
- * E-mail: (EJL); (SRK)
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22
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Control of the galactose-to-glucose consumption ratio in co-fermentation using engineered Escherichia coli strains. Sci Rep 2020; 10:12132. [PMID: 32699275 PMCID: PMC7376015 DOI: 10.1038/s41598-020-69143-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 06/29/2020] [Indexed: 11/26/2022] Open
Abstract
Marine biomasses capable of fixing carbon dioxide have attracted attention as an alternative to fossil resources for fuel and chemical production. Although a simple co-fermentation of fermentable sugars, such as glucose and galactose, has been reported from marine biomass, no previous report has discussed the fine-control of the galactose-to-glucose consumption ratio in this context. Here, we sought to finely control the galactose-to-glucose consumption ratio in the co-fermentation of these sugars using engineered Escherichia coli strains. Toward this end, we constructed E. coli strains GR2, GR2P, and GR2PZ by knocking out galRS, galRS-pfkA, and galRS-pfkA-zwf, respectively, in parent strain W3110. We found that strains W3110, GR2, GR2P, and GR2PZ achieved 0.03, 0.09, 0.12, and 0.17 galactose-to-glucose consumption ratio (specific galactose consumption rate per specific glucose consumption rate), respectively, during co-fermentation. The ratio was further extended to 0.67 by integration of a brief process optimization for initial sugar ratio using GR2P strain. The strategy reported in this study will be helpful to expand our knowledge on the galactose utilization under glucose conditions.
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23
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Kwon SW, Paari KA, Malaviya A, Jang YS. Synthetic Biology Tools for Genome and Transcriptome Engineering of Solventogenic Clostridium. Front Bioeng Biotechnol 2020; 8:282. [PMID: 32363182 PMCID: PMC7181999 DOI: 10.3389/fbioe.2020.00282] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Accepted: 03/17/2020] [Indexed: 12/18/2022] Open
Abstract
Strains of Clostridium genus are used for production of various value-added products including fuels and chemicals. Development of any commercially viable production process requires a combination of both strain and fermentation process development strategies. The strain development in Clostridium sp. could be achieved by random mutagenesis, and targeted gene alteration methods. However, strain improvement in Clostridium sp. by targeted gene alteration method was challenging due to the lack of efficient tools for genome and transcriptome engineering in this organism. Recently, various synthetic biology tools have been developed to facilitate the strain engineering of solventogenic Clostridium. In this review, we consolidated the recent advancements in toolbox development for genome and transcriptome engineering in solventogenic Clostridium. Here we reviewed the genome-engineering tools employing mobile group II intron, pyrE alleles exchange, and CRISPR/Cas9 with their application for strain development of Clostridium sp. Next, transcriptome engineering tools such as untranslated region (UTR) engineering and synthetic sRNA techniques were also discussed in context of Clostridium strain engineering. Application of any of these discussed techniques will facilitate the metabolic engineering of clostridia for development of improved strains with respect to requisite functional attributes. This might lead to the development of an economically viable butanol production process with improved titer, yield and productivity.
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Affiliation(s)
- Seong Woo Kwon
- Department of Agricultural Chemistry and Food Science Technology, Division of Applied Life Science (BK21 Plus Program), Institute of Agriculture & Life Science (IALS), Gyeongsang National University, Jinju, South Korea
| | | | - Alok Malaviya
- Applied and Industrial Biotechnology Laboratory (AIBL), Department of Life Sciences, CHRIST (Deemed to be University), Bengaluru, India
| | - Yu-Sin Jang
- Department of Agricultural Chemistry and Food Science Technology, Division of Applied Life Science (BK21 Plus Program), Institute of Agriculture & Life Science (IALS), Gyeongsang National University, Jinju, South Korea
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24
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Lee S, Choi JI, Woo HM. Bioconversion of Xylose to Ethylene Glycol and Glycolate in Engineered Corynebacterium glutamicum. ACS OMEGA 2019; 4:21279-21287. [PMID: 31867522 PMCID: PMC6921644 DOI: 10.1021/acsomega.9b02805] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 11/20/2019] [Indexed: 05/05/2023]
Abstract
The biological production of two-carbon compounds (ethylene glycol (EG) and glycolate) has been studied for the sustainable supply of the compounds to the polymer, cosmetic, textile, and medical industries. Here, we demonstrated the bioconversion of xylose to either ethylene glycol (EG) or glycolate using engineered Corynebacterium glutamicum, a well-known industrial amino acid producer. A synthetic ribulose 1-phosphate (Ru1P) pathway involving heterologous d-tagatose 3-epimerase and l-fuculose kinase/aldolase reactions was introduced in C. glutamicum. Subsequently, heterologous expression of Escherichia coli YqhD reductase with the synthetic Ru1P pathway led to ethylene glycol production from xylose. Additional pathway engineering in C. glutamicum by mutating ald, which encodes an aldehyde dehydrogenase, abolished the by-product formation of glycolate during xylose conversion to EG at a yield of 0.75 mol per mol. In addition, the bioconversion of xylose to glycolate was achieved, and the almost maximum molar yield was 0.99 mol per mol xylose in C. glutamicum via the Ru1P pathway. Thus, the synthetic Ru1P pathway in C. glutamicum led bioconversion of xylose to either ethylene glycol or glycolate with high molar yields.
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Affiliation(s)
- Seung
Soo Lee
- Department
of Food Science and Biotechnology, Sungkyunkwan
University (SKKU), 2066 Seobu-ro, Jangan-gu, Suwon 16419, Republic of Korea
| | - Jong-il Choi
- Department
of Biotechnology and Bioengineering, Chonnam
National University, 77 Yongbong-ro, Buk-gu, Gwangju 61186, Republic of Korea
| | - Han Min Woo
- Department
of Food Science and Biotechnology, Sungkyunkwan
University (SKKU), 2066 Seobu-ro, Jangan-gu, Suwon 16419, Republic of Korea
- E-mail: . Tel: +82 31 290 7808. Fax: +82 31 290 7882
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