1
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Ma Y, Guo N, Wang S, Wang Y, Jiang Z, Guo L, Luo W, Wang Y. Metabolically engineer Clostridium saccharoperbutylacetonicum for comprehensive conversion of acid whey into valuable biofuels and biochemicals. BIORESOURCE TECHNOLOGY 2024; 400:130640. [PMID: 38554761 DOI: 10.1016/j.biortech.2024.130640] [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: 01/20/2024] [Revised: 03/15/2024] [Accepted: 03/25/2024] [Indexed: 04/02/2024]
Abstract
As a byproduct of dairy production, the disposal of acid whey poses severe environmental challenges. Herein, an innovative solution involving metabolically engineering Clostridium saccharoperbutylacetonicum to convert all carbon sources in acid whey into sustainable biofuels and biochemicals was presented. By introducing several heterologous metabolic pathways relating to metabolisms of lactose, galactose, and lactate, the ultimately optimized strain, LM-09, exhibited exceptional performance by producing 15.1 g/L butanol with a yield of 0.33 g/g and a selectivity of 89.9%. Through further overexpression of alcohol acyl transferase, 2.7 g/L butyl acetate along with 6.4 g/L butanol was generated, resulting in a combined yield of 0.37 g/g. This study achieves the highest reported butanol titer and yield using acid whey as substrate in clostridia and marks pioneering production of esters using acid whey. The findings demonstrate an innovative bioprocess that enhances renewable feedstock biotransformation, thereby promoting economic viability and environmental sustainability of biomanufacturing.
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Affiliation(s)
- Yuechao Ma
- Department of Biosystems Engineering, Auburn University, Auburn, AL 36849, USA; Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL 36849, USA
| | - Na Guo
- Department of Biosystems Engineering, Auburn University, Auburn, AL 36849, USA; Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL 36849, USA
| | - Shangjun Wang
- Department of Biosystems Engineering, Auburn University, Auburn, AL 36849, USA; Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL 36849, USA
| | - Yifen Wang
- Department of Biosystems Engineering, Auburn University, Auburn, AL 36849, USA; Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL 36849, USA
| | - Zhihua Jiang
- Department of Chemical Engineering, Auburn University, Auburn, AL 36849, USA
| | - Liang Guo
- College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Wei Luo
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Yi Wang
- Department of Biosystems Engineering, Auburn University, Auburn, AL 36849, USA; Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL 36849, USA.
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2
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Joseph RC, Kelley SQ, Kim NM, Sandoval NR. Metabolic Engineering and the Synthetic Biology Toolbox for
Clostridium. Metab Eng 2021. [DOI: 10.1002/9783527823468.ch16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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3
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Liu T, Malkmes MJ, Zhu L, Huang H, Jiang L. Metal-organic frameworks coupling simultaneous saccharication and fermentation for enhanced butyric acid production from rice straw under visible light by Clostridium tyrobutyricum CtΔack::cat1. BIORESOURCE TECHNOLOGY 2021; 332:125117. [PMID: 33845315 DOI: 10.1016/j.biortech.2021.125117] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 03/27/2021] [Accepted: 03/29/2021] [Indexed: 06/12/2023]
Abstract
Here, Metal-Organic Frameworks (MOFs) coupling simultaneous saccharification and fermentation for butyric acid production using rice straw was constructed. Clostridium tyrobutyricum Δack::cat1, with deleted ack gene and overexpressed cat1 gene, was used as the butyric-acid-fermentation strain. MOFs was employed as a photocatalyst to improve butyric acid production, as well as a cytoprotective exoskeleton with immobilized cellulase for the hydrolysis of rice straw. Thus, the survival of MOFs-coated strain, the thermostability and pH stability of cellulase both remarkably increased. As a result, 55% of rice straw was hydrolyzed in 24 h, and the final concentration of butyric acid in visible light was increased by 14.23% and 29.16% compared to uncoated and coated strain without visible light, respectively. Finally, 26.25 g/L of butyric acid with a productivity of 0.41 g/L·h in fed-batch fermentation was obtained. This novel process inspires green approach of abundant low-cost feedstocks utilization for chemical production.
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Affiliation(s)
- Tingting Liu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 210009, People's Republic of China; College of Food Science and Light Industry, Nanjing Tech University, Nanjing 210009, People's Republic of China
| | - Matthew Jay Malkmes
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing 210009, People's Republic of China
| | - Liying Zhu
- College of Chemical and Molecular Engineering, Nanjing Tech University, Nanjing 210009, People's Republic of China
| | - He Huang
- College of Pharmaceutical Science, Nanjing Tech University, Nanjing 210009, People's Republic of China
| | - Ling Jiang
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing 210009, People's Republic of China.
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4
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Li W, Cheng C, Cao G, Yang ST, Ren N. Comparative transcriptome analysis of Clostridium tyrobutyricum expressing a heterologous uptake hydrogenase. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 749:142022. [PMID: 33370888 DOI: 10.1016/j.scitotenv.2020.142022] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 08/25/2020] [Accepted: 08/25/2020] [Indexed: 06/12/2023]
Abstract
Clostridium tyrobutyricum is a promising microbial cell factory to produce biofuels. In this study, an uptake hydrogenase (hyd2293) from Ethanoligenens harbinense was overexpressed in C. tyrobutyricum and significantly affected the redox reactions and metabolic profiles. Compared to the parental strain (Ct-WT), the mutant strain Ct-Hyd2293 produced ~34% less butyrate, ~148% more acetate, and ~11% less hydrogen, accompanied by the emerging genesis of butanol. Comparative transcriptome analysis revealed that 666 genes were significantly differentially expressed after the overexpression of hyd2293, including 82 up-regulated genes and 584 down-regulated genes. The up-regulated genes were mainly involved in carbohydrate and energy metabolisms while the down-regulated genes were distributed in nearly all pathways. Genes involved in glucose transportation, glycolysis, different fermentation pathways and hydrogen metabolism were studied and the gene expression changes showed the mechanism of the metabolic flux redistribution in Ct-Hyd2293. The overexpression of uptake hydrogenase redirected electrons from hydrogen and butyrate to butanol. The key enzymes participating in the energy conservation and sporulation were also identified and their transcription levels were generally reduced. This study demonstrated the transcriptomic responses of C. tyrobutyricum to the expression of a heterologous uptake hydrogenase, which provided a better understanding of the metabolic characteristics of C. tyrobutyricum and demonstrated the potential role of redox manipulation in metabolic engineering for biofuel productions.
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Affiliation(s)
- Weiming Li
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China; Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH 43210, USA
| | - Chi Cheng
- Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH 43210, USA; School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Guangli Cao
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Shang-Tian Yang
- Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH 43210, USA
| | - Nanqi Ren
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
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5
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Liu T, Jiang C, Zhu L, Jiang L, Huang H. Fe 3O 4@chitosan Microspheres Coating as Cytoprotective Exoskeletons for the Enhanced Production of Butyric Acid With Clostridium tyrobutyricum Under Acid Stress. Front Bioeng Biotechnol 2020; 8:449. [PMID: 32500066 PMCID: PMC7243709 DOI: 10.3389/fbioe.2020.00449] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 04/17/2020] [Indexed: 11/13/2022] Open
Abstract
The introduction of inorganic nano-materials may endow microbial cells with unique new features, including greater resistance to adverse abiotic stress. The aim of this work was to enhance the acid tolerance of Clostridium tyrobutyricum ATCC 25755 by coating cells with self-assembled Fe3O4@chitosan (Fe3O4@CS) microspheres, and thereby increase the production of butyric acid. The optimal coating efficiency of 81.19% was obtained by systematically optimizing the three operational parameters temperature, rpm and mass ratio, which were determined to be 37°C, 80 rpm and 1:2, respectively. Physicochemical characterization was used to assess the superparamagnetism, thermostability and subsize of Fe3O4@CS attached to the cells. Compared to free cells, C. tyrobutyricum coated with Fe3O4@CS (CtFC) exhibited stronger acid tolerance at low pH. At a pH of 4 or 5, the levels of ROS, MDA, LDH, and SOD caused by the acid environment in free cells were significant higher than in CtFC. Moreover, without adding NaOH, CtFC fermentation showed a higher butyric acid titer (37.60 vs. 31.56 g/L) compared to free-cell fermentation. At the same time, an average butyric acid yield of 0.46 g/g in each repeated-batch fermentation was also obtained by taking advantage of the biocatalyst’s reusability and convenient separation from the fermentation broth via an external magnetic force. Overall, the developed CtFC illustrates a new paradigm for developing an economical and reusable biocatalyst for industrial application in butyric acid production.
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Affiliation(s)
- Tingting Liu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China.,College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
| | - Cheng Jiang
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
| | - Liying Zhu
- College of Chemical and Molecular Engineering, Nanjing Tech University, Nanjing, China
| | - Ling Jiang
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
| | - He Huang
- College of Pharmaceutical Science, Nanjing Tech University, Nanjing, China
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6
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Understanding metabolic adaptation by using bacterial laboratory evolution and trans-omics analysis. Biophys Rev 2020; 12:677-682. [PMID: 32394353 DOI: 10.1007/s12551-020-00695-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 04/28/2020] [Indexed: 12/16/2022] Open
Abstract
Many diseases such as metabolic syndrome, cancer, inflammatory diseases, and pathological phenomena can be understood as an adaptive reconstitution of the metabolic state (metabolic adaptation). One of the effective approaches to reveal the property of metabolic networks is using model organisms such as microorganisms that are easier to experiment with than higher organisms. Using the laboratory evolution approach, we can elucidate the evolutionary dynamics in various stress environments, which provide us an understanding of the metabolic adaptation. In addition, the integration of omics data and phenotypic data enables us to clarify the genetic and phenotypic alterations during adaptation. In this review, we describe our recent studies on bacterial laboratory evolution and the omics approach to clarify the stress adaptation process. We have also obtained high-dimensional phenotypic data using our automated culture system. By combining these genomic and transcriptomic data within high-throughput phenotypic data, we can discuss the complex trans-omics network of metabolic adaptation.
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7
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Choudhury D, Saini S. Evolution of Escherichia coli in different carbon environments for 2,000 generations. J Evol Biol 2019; 32:1331-1341. [PMID: 31397932 DOI: 10.1111/jeb.13517] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 06/30/2019] [Accepted: 07/29/2019] [Indexed: 11/28/2022]
Abstract
Cellular energetics is thought to have played a key role in dictating all major evolutionary transitions in the history of life on Earth. However, how exactly cellular energetics and metabolism come together to shape evolutionary paths is not well understood. In particular, when an organism is evolved in different energy environments, what are the phenomenological differences in the chosen evolutionary trajectories, is a question that is not well understood. In this context, starting from an Escherichia coli K-12 strain, we evolve the bacterium in five different carbon environments-glucose, arabinose, xylose, rhamnose and a mixture of these four sugars (in a predefined ratio) for approximately 2,000 generations. At the end of the adaptation period, we quantify and compare the growth dynamics of the strains in a variety of environments. The evolved strains show no specialized adaptation towards growth in the carbon medium in which they were evolved. Rather, in all environments, the evolved strains exhibited a reduced lag phase and an increased growth rate. Sequencing results reveal that these dynamical properties are not introduced via mutations in the precise loci associated with utilization of the sugar in which the bacterium evolved. These phenotypic changes are rather likely introduced via mutations elsewhere on the genome. Data from our experiments indicate that evolution in a defined environment does not alter hierarchy in mixed-sugar utilization in bacteria.
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Affiliation(s)
- Debika Choudhury
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Supreet Saini
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
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8
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Sandberg TE, Salazar MJ, Weng LL, Palsson BO, Feist AM. The emergence of adaptive laboratory evolution as an efficient tool for biological discovery and industrial biotechnology. Metab Eng 2019; 56:1-16. [PMID: 31401242 DOI: 10.1016/j.ymben.2019.08.004] [Citation(s) in RCA: 262] [Impact Index Per Article: 52.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 08/01/2019] [Accepted: 08/05/2019] [Indexed: 12/21/2022]
Abstract
Harnessing the process of natural selection to obtain and understand new microbial phenotypes has become increasingly possible due to advances in culturing techniques, DNA sequencing, bioinformatics, and genetic engineering. Accordingly, Adaptive Laboratory Evolution (ALE) experiments represent a powerful approach both to investigate the evolutionary forces influencing strain phenotypes, performance, and stability, and to acquire production strains that contain beneficial mutations. In this review, we summarize and categorize the applications of ALE to various aspects of microbial physiology pertinent to industrial bioproduction by collecting case studies that highlight the multitude of ways in which evolution can facilitate the strain construction process. Further, we discuss principles that inform experimental design, complementary approaches such as computational modeling that help maximize utility, and the future of ALE as an efficient strain design and build tool driven by growing adoption and improvements in automation.
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Affiliation(s)
- Troy E Sandberg
- Department of Bioengineering, University of California, San Diego, CA, 92093, USA
| | - Michael J Salazar
- Department of Bioengineering, University of California, San Diego, CA, 92093, USA
| | - Liam L Weng
- Department of Bioengineering, University of California, San Diego, CA, 92093, USA
| | - Bernhard O Palsson
- Department of Bioengineering, University of California, San Diego, CA, 92093, USA; Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Lyngby, Denmark
| | - Adam M Feist
- Department of Bioengineering, University of California, San Diego, CA, 92093, USA; Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Lyngby, Denmark.
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9
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Lv Z, Zhou J, Zhang Y, Zhou X, Xu N, Xin F, Ma J, Jiang M, Dong W. Techniques for enhancing the tolerance of industrial microbes to abiotic stresses: A review. Biotechnol Appl Biochem 2019; 67:73-81. [PMID: 31206805 DOI: 10.1002/bab.1794] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 06/05/2019] [Indexed: 12/20/2022]
Abstract
The diversity of stress responses and survival strategies evolved by microorganism enables them to survive and reproduce in a multitude of harsh environments, whereas the discovery of the underlying resistance genes or mechanisms laid the foundation for the directional enhancement of microbial tolerance to abiotic stresses encountered in industrial applications. Many biological techniques have been developed for improving the stress resistance of industrial microorganisms, which greatly benefited the bacteria on which industrial production is based. This review introduces the main techniques for enhancing the resistance of microorganisms to abiotic stresses, including evolutionary engineering, metabolic engineering, and process engineering, developed in recent years. In addition, we also discuss problems that are still present in this area and offer directions for future research.
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Affiliation(s)
- Ziyao Lv
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800, Peoples' Republic of China
| | - Jie Zhou
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800, Peoples' Republic of China.,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800, Peoples' Republic of China
| | - Yue Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800, Peoples' Republic of China
| | - Xinhai Zhou
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800, Peoples' Republic of China
| | - Ning Xu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800, Peoples' Republic of China
| | - Fengxue Xin
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800, Peoples' Republic of China.,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800, Peoples' Republic of China
| | - Jiangfeng Ma
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800, Peoples' Republic of China.,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800, Peoples' Republic of China
| | - Min Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800, Peoples' Republic of China.,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800, Peoples' Republic of China
| | - Weiliang Dong
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800, Peoples' Republic of China.,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800, Peoples' Republic of China
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10
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Ra CH, Sunwoo IY, Nguyen TH, Sukwong P, Sirisuk P, Jeong GT, Kim SK. Butanol and butyric acid production from Saccharina japonica by Clostridium acetobutylicum and Clostridium tyrobutyricum with adaptive evolution. Bioprocess Biosyst Eng 2019; 42:583-592. [PMID: 30788572 DOI: 10.1007/s00449-018-02063-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 12/12/2018] [Indexed: 11/26/2022]
Abstract
Optimal conditions of hyper thermal (HT) acid hydrolysis of the Saccharina japonica was determined to a seaweed slurry content of 12% (w/v) and 144 mM H2SO4 at 160 °C for 10 min. Enzymatic saccharification was carried out at 50 °C and 150 rpm for 48 h using the three enzymes at concentrations of 16 U/mL. Celluclast 1.5 L showed the lowest half-velocity constant (Km) of 0.168 g/L, indicating a higher affinity for S. japonica hydrolysate. Pretreatment yielded a maximum monosaccharide concentration of 36.2 g/L and 45.7% conversion from total fermentable monosaccharides of 79.2 g/L with 120 g dry weight/L S. japonica slurry. High cell densities of Clostridium acetobutylicum and Clostridium tyrobutyricum were obtained using the retarding agents KH2PO4 (50 mM) and NaHCO3 (200 mM). Adaptive evolution facilitated the efficient use of mixed monosaccharides. Therefore, adaptive evolution and retarding agents can enhance the overall butanol and butyric acid yields from S. japonica.
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Affiliation(s)
- Chae Hun Ra
- Department of Food Science and Biotechnology, Food and Bio-industry Research Center, Hankyong National University, Anseong, 17579, South Korea
| | - In Yung Sunwoo
- Department of Biotechnology, Pukyong National University, Busan, 48513, South Korea
| | - Trung Hau Nguyen
- Department of Biotechnology, Pukyong National University, Busan, 48513, South Korea
| | - Pailin Sukwong
- Department of Biotechnology, Pukyong National University, Busan, 48513, South Korea
| | - Phunlap Sirisuk
- Department of Biotechnology, Pukyong National University, Busan, 48513, South Korea
| | - Gwi-Taek Jeong
- Department of Biotechnology, Pukyong National University, Busan, 48513, South Korea
| | - Sung-Koo Kim
- Department of Biotechnology, Pukyong National University, Busan, 48513, South Korea.
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11
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Horinouchi T, Maeda T, Furusawa C. Understanding and engineering alcohol-tolerant bacteria using OMICS technology. World J Microbiol Biotechnol 2018; 34:157. [PMID: 30341456 PMCID: PMC6208762 DOI: 10.1007/s11274-018-2542-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 10/13/2018] [Indexed: 12/16/2022]
Abstract
Microbes are capable of producing alcohols, making them an important source of alternative energy that can replace fossil fuels. However, these alcohols can be toxic to the microbes themselves, retaring or inhibiting cell growth and decreasing the production yield. One solution is improving the alcohol tolerance of such alcohol-producing organisms. Advances in omics technologies, including transcriptomic, proteomic, metabolomic, and genomic technologies, have helped us understand the complex mechanisms underlying alcohol toxicity, and such advances could assist in devising strategies for engineering alcohol-tolerant strains. This review highlights these advances and discusses strategies for improving alcohol tolerance using omics analyses.
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Affiliation(s)
- Takaaki Horinouchi
- Center for Biosystems Dynamics Research (BDR), RIKEN, 6-2-3 Furuedai, Suita, Osaka, 565-0874, Japan.
| | - Tomoya Maeda
- Center for Biosystems Dynamics Research (BDR), RIKEN, 6-2-3 Furuedai, Suita, Osaka, 565-0874, Japan
| | - Chikara Furusawa
- Center for Biosystems Dynamics Research (BDR), RIKEN, 6-2-3 Furuedai, Suita, Osaka, 565-0874, Japan.
- Universal Biology Institute, The University of Tokyo, 7-3-1 Hongo, Tokyo, 113-0033, Japan.
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12
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Zhang AH, Zhuang XY, Chen KN, Huang SY, Xu CZ, Fang BS. Adaptive evolution of Clostridium butyricum
and scale-Up for high-Concentration 1,3-propanediol production. AIChE J 2018. [DOI: 10.1002/aic.16425] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Ai-Hui Zhang
- Dept. of Chemical and Biochemical Engineering; College of Chemistry and Chemical Engineering, Xiamen University; Xiamen Fujian 361005 China
| | - Xiao-Yan Zhuang
- Dept. of Chemical and Biochemical Engineering; College of Chemistry and Chemical Engineering, Xiamen University; Xiamen Fujian 361005 China
| | - Kai-Nan Chen
- Dept. of Chemical and Biochemical Engineering; College of Chemistry and Chemical Engineering, Xiamen University; Xiamen Fujian 361005 China
| | - Shi-Yang Huang
- Dept. of Chemical and Biochemical Engineering; College of Chemistry and Chemical Engineering, Xiamen University; Xiamen Fujian 361005 China
| | - Chao-Zhen Xu
- Dept. of Chemical and Biochemical Engineering; College of Chemistry and Chemical Engineering, Xiamen University; Xiamen Fujian 361005 China
| | - Bai-Shan Fang
- Dept. of Chemical and Biochemical Engineering; College of Chemistry and Chemical Engineering, Xiamen University; Xiamen Fujian 361005 China
- The Key Lab for Synthetic Biotechnology of Xiamen City; Xiamen University; Xiamen Fujian 361005 China
- The National Engineering Laboratory for Green Chemical Productions of Alcohols-Ethers-Esters; Xiamen University; Xiamen Fujian 361005 China
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13
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Jiang L, Fu H, Yang HK, Xu W, Wang J, Yang ST. Butyric acid: Applications and recent advances in its bioproduction. Biotechnol Adv 2018; 36:2101-2117. [PMID: 30266343 DOI: 10.1016/j.biotechadv.2018.09.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 09/24/2018] [Accepted: 09/24/2018] [Indexed: 12/20/2022]
Abstract
Butyric acid is an important C4 organic acid with broad applications. It is currently produced by chemosynthesis from petroleum-based feedstocks. However, the fermentative production of butyric acid from renewable feedstocks has received growing attention because of consumer demand for green products and natural ingredients in foods, pharmaceuticals, animal feed supplements, and cosmetics. In this review, strategies for improving microbial butyric acid production, including strain engineering and novel fermentation process development are discussed and compared regarding product yield, titer, purity and productivity. Future perspectives on strain and process improvements for butyric acid production are also discussed.
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Affiliation(s)
- Ling Jiang
- School of Biology & Biological Engineering, South China University of Technology, Guangzhou 510006, China; College of Food Science and Light Industry, Nanjing Tech University, No. 5 Xinmofan Road, Nanjing 210009, China
| | - Hongxin Fu
- School of Biology & Biological Engineering, South China University of Technology, Guangzhou 510006, China
| | - Hopen K Yang
- Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH 43210, USA
| | - Wei Xu
- Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH 43210, USA; School of Chemical and Biological Engineering, Yancheng Institute of Technology, Yancheng 224051, China
| | - Jufang Wang
- School of Biology & Biological Engineering, South China University of Technology, Guangzhou 510006, China; Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH 43210, USA.
| | - Shang-Tian Yang
- Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH 43210, USA.
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14
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Suo Y, Ren M, Yang X, Liao Z, Fu H, Wang J. Metabolic engineering of Clostridium tyrobutyricum for enhanced butyric acid production with high butyrate/acetate ratio. Appl Microbiol Biotechnol 2018; 102:4511-4522. [DOI: 10.1007/s00253-018-8954-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 03/15/2018] [Accepted: 03/18/2018] [Indexed: 11/30/2022]
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15
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Enhanced butyric acid production in Clostridium tyrobutyricum by overexpression of rate-limiting enzymes in the Embden-Meyerhof-Parnas pathway. J Biotechnol 2018; 272-273:14-21. [PMID: 29501473 DOI: 10.1016/j.jbiotec.2018.02.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2017] [Revised: 02/23/2018] [Accepted: 02/27/2018] [Indexed: 11/22/2022]
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16
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Li C, Gao S, Li X, Yang X, Lin CSK. Efficient metabolic evolution of engineered Yarrowia lipolytica for succinic acid production using a glucose-based medium in an in situ fibrous bioreactor under low-pH condition. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:236. [PMID: 30181775 PMCID: PMC6116362 DOI: 10.1186/s13068-018-1233-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 08/22/2018] [Indexed: 05/02/2023]
Abstract
BACKGROUND Alkali used for pH control during fermentation and acidification for downstream recovery of succinic acid (SA) are the two largest cost contributors for bio-based SA production. To promote the commercialization process of fermentative SA, the development of industrially important microorganisms that can tolerate low pH has emerged as a crucial issue. RESULTS In this study, an in situ fibrous bed bioreactor (isFBB) was employed for the metabolic evolution for selection of Y. lipolytica strain that can produce SA at low pH using glucose-based medium. An evolved strain named Y. lipolytica PSA3.0 that could produce SA with a titer of 19.3 g/L, productivity of 0.52 g/L/h, and yield of 0.29 g/g at pH 3.0 from YPD was achieved. The enzyme activity analysis demonstrated that the pathway from pyruvate to acetate was partially blocked in Y. lipolytica PSA3.0 after the evolution, which is beneficial to cell growth and SA production at low pH. When free-cell batch fermentations were performed using the parent and evolved strains separately, the evolved strain PSA3.0 produced 18.4 g/L SA with a yield of 0.23 g/g at pH 3.0. Although these values were lower than that obtained by the parent strain PSA02004 at its optimal pH 6.0, which were 25.2 g/L and 0.31 g/g, respectively, they were 4.8 and 4.6 times higher than that achieved by PSA02004 at pH 3.0. By fed-batch fermentation, the resultant SA titer of 76.8 g/L was obtained, which is the highest value that ever achieved from glucose-based medium at low pH, to date. When using mixed food waste (MFW) hydrolysate as substrate, 18.9 g/L SA was produced with an SA yield of 0.38 g/g, which demonstrates the feasibility of using low-cost glucose-based hydrolysate for SA production by Y. lipolytica in a low-pH environment. CONCLUSIONS This study presents an effective and efficient strategy for the evolution of Y. lipolytica for SA production under low-pH condition for the first time. The isFBB was demonstrated to improve the metabolic evolution efficiency of Y. lipolytica to the acidic condition. Moreover, the acetate accumulation was found to be the major reason for the inhibition of SA production at low pH by Y. lipolytica, which suggested the direction for further metabolic modification of the strain for improved SA production. Furthermore, the evolved strain Y. lipolytica PSA3.0 was demonstrated to utilize glucose-rich hydrolysate from MFW for fermentative SA production at low pH. Similarly, Y. lipolytica PSA3.0 is expected to utilize the glucose-rich hydrolysate generated from other carbohydrate-rich waste streams for SA production. This study paves the way for the commercialization of bio-based SA and contributes to the sustainable development of a green economy.
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Affiliation(s)
- Chong Li
- School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong
- Agricultural Genomic Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518120 Guangdong People’s Republic of China
| | - Shi Gao
- School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong
| | - Xiaotong Li
- School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong
| | - Xiaofeng Yang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006 People’s Republic of China
| | - Carol Sze Ki Lin
- School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong
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17
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Wu Q, Zhu L, Xu Q, Huang H, Jiang L, Yang ST. Tailoring the Oxidative Stress Tolerance of Clostridium tyrobutyricum CCTCC W428 by Introducing Trehalose Biosynthetic Capability. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2017; 65:8892-8901. [PMID: 28925260 DOI: 10.1021/acs.jafc.7b03172] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Fermentations employing anaerobes always suffer from the restriction of stringent anaerobic conditions during the production of bulk and fine chemicals. This work aims to improve the oxidative stress tolerance of C. tyrobutyricum CCTCC W428, an ideal butyric-acid-producing anaerobe, via the introduction of trehalose biosynthesis capability. Compared with the wild type, the engineered strain showed a wider substrate spectrum, an improved metabolic profile, and a significantly increased specific growth rate upon aeration and acid challenge. Molecular simulation experiments indicated that CoA transferase maintained its native folded state when protected by the trehalose system. Furthermore, qRT-PCR was combined assays for acid-related enzyme activities under various conditions to verify the effects of trehalose. These results demonstrate that introducing a trehalose biosynthetic pathway, which is redundant for the metabolism of C. tyrobutyricum, can increase the robustness of the host to achieve a better oxidative resistance.
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Affiliation(s)
| | | | | | | | | | - Shang-Tian Yang
- Department of Chemical Engineering, The Ohio State University , Columbus, Ohio 43210, United States
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18
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Fermentative hydrogen production from Jerusalem artichoke by Clostridium tyrobutyricum expressing exo-inulinase gene. Sci Rep 2017; 7:7940. [PMID: 28801602 PMCID: PMC5554141 DOI: 10.1038/s41598-017-07207-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 06/23/2017] [Indexed: 12/01/2022] Open
Abstract
Clostridium tyrobutyricum ATCC25755 has been reported as being able to produce significant quantities of hydrogen. In this study, the exo-inulinase encoding gene cloned from Paenibacillus polymyxa SC-2 was into the expression plasmid pSY6 and expressed in the cells of C. tyrobutyricum. The engineered C. tyrobutyricum strain efficiently fermented the inulin-type carbohydrates from Jerusalem artichoke, without any pretreatment being necessary for the production of hydrogen. A comparatively high hydrogen yield (3.7 mol/mol inulin-type sugar) was achieved after 96 h in a batch process with simultaneous saccharification and fermentation (SSF), with an overall volumetric productivity rate of 620 ± 60 mL/h/L when the initial total sugar concentration of the inulin extract was increased to 100 g/L. Synthesis of inulinase in the batch SSF culture was closely associated with strain growth until the end of the exponential phase, reaching a maximum activity of 28.4 ± 0.26 U/mL. The overall results show that the highly productive and abundant biomass crop Jerusalem artichoke can be a good substrate for hydrogen production, and that the application of batch SSF for its conversion has the potential to become a cost-effective process in the near future.
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19
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Yang X, Wang H, Li C, Lin CSK. Restoring of Glucose Metabolism of Engineered Yarrowia lipolytica for Succinic Acid Production via a Simple and Efficient Adaptive Evolution Strategy. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2017; 65:4133-4139. [PMID: 28474529 DOI: 10.1021/acs.jafc.7b00519] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Succinate dehydrogenase inactivation in Yarrowia lipolytica has been demonstrated for robust succinic acid production, whereas the inefficient glucose metabolism has hindered its practical application. In this study, a simple and efficient adaptive evolution strategy via cell immobilization was conducted in shake flasks, with an aim to restore the glucose metabolism of Y. lipolytica mutant PGC01003. After 21 days with 14 generations evolution, glucose consumption rate increased to 0.30 g/L/h in YPD medium consisting of 150 g/L initial glucose concentration, while poor yeast growth was observed in the same medium using the initial strain without adaptive evolution. Succinic acid productivity of the evolved strain also increased by 2.3-fold, with stable cell growth in YPD medium with high initial glucose concentration. Batch fermentations resulted in final succinic acid concentrations of 65.7 g/L and 87.9 g/L succinic acid using YPD medium and food waste hydrolysate, respectively. The experimental results in this study show that a simple and efficient strategy could facilitate the glucose uptake rate in succinic acid fermentation using glucose-rich substrates.
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Affiliation(s)
- Xiaofeng Yang
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology , Guangzhou 510006, People's Republic of China
- School of Energy and Environment, City University of Hong Kong , Tat Chee Avenue, Kowloon, Hong Kong, People's Republic of China
| | - Huaimin Wang
- School of Energy and Environment, City University of Hong Kong , Tat Chee Avenue, Kowloon, Hong Kong, People's Republic of China
| | - Chong Li
- School of Energy and Environment, City University of Hong Kong , Tat Chee Avenue, Kowloon, Hong Kong, People's Republic of China
| | - Carol Sze Ki Lin
- School of Energy and Environment, City University of Hong Kong , Tat Chee Avenue, Kowloon, Hong Kong, People's Republic of China
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20
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Wu Q, Liu T, Zhu L, Huang H, Jiang L. Insights from the complete genome sequence of Clostridium tyrobutyricum provide a platform for biotechnological and industrial applications. J Ind Microbiol Biotechnol 2017; 44:1245-1260. [PMID: 28536840 DOI: 10.1007/s10295-017-1956-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 05/18/2017] [Indexed: 11/26/2022]
Abstract
Genetic research enables the evolution of novel biochemical reactions for the production of valuable chemicals from environmentally-friendly raw materials. However, the choice of appropriate microorganisms to support these reactions, which must have strong robustness and be capable of a significant product output, is a major difficulty. In the present study, the complete genome of the Clostridium tyrobutyricum strain CCTCC W428, a hydrogen- and butyric acid-producing bacterium with increased oxidative tolerance was analyzed. A total length of 3,011,209 bp of the C. tyrobutyricum genome with a GC content of 31.04% was assembled, and 3038 genes were discovered. Furthermore, a comparative clustering of proteins from C. tyrobutyricum CCTCC W428, C. acetobutylicum ATCC 824, and C. butyricum KNU-L09 was conducted. The results of genomic analysis indicate that butyric acid is produced by CCTCC W428 from butyryl-CoA through acetate reassimilation via CoA transferase, instead of the well-established phosphotransbutyrylase-butyrate kinase pathway. In addition, we identified ten proteins putatively involved in hydrogen production and 21 proteins associated with CRISPR systems, together with 358 ORFs related to ABC transporters and transcriptional regulators. Enzymes, such as oxidoreductases, HNH endonucleases, and catalase, were also found in this species. The genome sequence illustrates that C. tyrobutyricum has several desirable traits, and is expected to be suitable as a platform for the high-level production of bulk chemicals as well as bioenergy.
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Affiliation(s)
- Qian Wu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 210019, People's Republic of China
- Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing, 210019, People's Republic of China
| | - Tingting Liu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 210019, People's Republic of China
- Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing, 210019, People's Republic of China
| | - Liying Zhu
- College of Chemical and Molecular Engineering, Nanjing Tech University, Nanjing, 210019, People's Republic of China
| | - He Huang
- College of Pharmaceutical Sciences, Nanjing Tech University, Nanjing, 210009, People's Republic of China
| | - Ling Jiang
- Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing, 210019, People's Republic of China.
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, 210009, People's Republic of China.
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21
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Wang J, Lin M, Xu M, Yang ST. Anaerobic Fermentation for Production of Carboxylic Acids as Bulk Chemicals from Renewable Biomass. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2016; 156:323-361. [DOI: 10.1007/10_2015_5009] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Yang X, Zhu M, Huang X, Lin CSK, Wang J, Li S. Valorisation of mixed bakery waste in non-sterilized fermentation for L-lactic acid production by an evolved Thermoanaerobacterium sp. strain. BIORESOURCE TECHNOLOGY 2015; 198:47-54. [PMID: 26363501 DOI: 10.1016/j.biortech.2015.08.108] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2015] [Revised: 08/21/2015] [Accepted: 08/22/2015] [Indexed: 06/05/2023]
Abstract
In this study, an advanced biorefinery technology that uses mixed bakery waste has been developed to produce l-lactic acid using an adaptively evolved Thermoanaerobacterium aotearoense LA1002-G40 in a non-sterilized system. Under these conditions, mixed bakery waste was directly hydrolysed by Aspergillus awamori and Aspergillus oryzae, resulting in a nutrient-rich hydrolysate containing 83.6g/L glucose, 9.5 g/L fructose and 612 mg/L free amino nitrogen. T. aotearoense LA1002-G40 was evaluated and then adaptively evolved to grow in this nutrient-rich hydrolysate. Using a 5-L fermenter, the overall lactic acid production from mixed bakery waste was 0.18 g/g with a titer, productivity and yield of 78.5 g/L, 1.63 g/L/h and 0.85 g/g, respectively. This is an innovative procedure involving a complete bioconversion process for l-lactic acid produced from mixed bakery waste under non-sterilized conditions. The proposed process could be potentially applied to turn food waste into l-lactic acid in an economically feasible way.
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Affiliation(s)
- Xiaofeng Yang
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, China; School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong
| | - Muzi Zhu
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, China
| | - Xiongliang Huang
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, China
| | - Carol Sze Ki Lin
- School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong
| | - Jufang Wang
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, China
| | - Shuang Li
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, China.
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23
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Succinic acid production from hemicellulose hydrolysate by an Escherichia coli mutant obtained by atmospheric and room temperature plasma and adaptive evolution. Enzyme Microb Technol 2014; 66:10-5. [PMID: 25248693 DOI: 10.1016/j.enzmictec.2014.04.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 03/27/2014] [Accepted: 04/28/2014] [Indexed: 10/25/2022]
Abstract
Atmospheric and room temperature plasma and adaptive evolution were combined to generate Escherichia coli mutants, which can simultaneously and efficiently utilize glucose and xylose to produce succinic acid in chemically defined medium under exclusively anaerobic condition. Compared to the parent strain BA305, a pflB, ldhA, ppc, and ptsG deletion strain overexpressing ATP-forming phosphoenolpyruvate (PEP) carboxykinase (PEPCK), the sugar consumption rate and succinic acid productivity of mutant BA408 were significantly improved with a marked increase in the key enzyme activities. Subsequent anaerobic fermentation of BA408 with corn stalk hydrolysate produced a final succinic acid concentration of 23.1 g L(-1) with a yield of 0.85 g g(-1) sugar mixture. The observed synthesis of succinic acid from the corn stalk hydrolysate showed a great potential usage of renewable biomass as a feedstock for an economical succinic acid production using E. coli.
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24
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Jiang L, Lin M, Zhang Y, Li Y, Xu X, Li S. Identification and characterization of a novel trehalose synthase gene derived from saline-alkali soil metagenomes. PLoS One 2013; 8:e77437. [PMID: 24146994 PMCID: PMC3797794 DOI: 10.1371/journal.pone.0077437] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 09/09/2013] [Indexed: 11/19/2022] Open
Abstract
A novel trehalose synthase (TreS) gene was identified from a metagenomic library of saline-alkali soil by a simple activity-based screening system. Sequence analysis revealed that TreS encodes a protein of 552 amino acids, with a deduced molecular weight of 63.3 kDa. After being overexpressed in Escherichia coli and purified, the enzymatic properties of TreS were investigated. The recombinant TreS displayed its optimal activity at pH 9.0 and 45 °C, and the addition of most common metal ions (1 or 30 mM) had no inhibition effect on the enzymatic activity evidently, except for the divalent metal ions Zn2+ and Hg2+. Kinetic analysis showed that the recombinant TreS had a 4.1-fold higher catalytic efficientcy (Kcat/Km) for maltose than for trehalose. The maximum conversion rate of maltose into trehalose by the TreS was reached more than 78% at a relatively high maltose concentration (30%), making it a good candidate in the large-scale production of trehalsoe after further study. In addition, five amino acid residues, His172, Asp201, Glu251, His318 and Asp319, were shown to be conserved in the TreS, which were also important for glycosyl hydrolase family 13 enzyme catalysis.
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Affiliation(s)
- Ling Jiang
- College of Food Science and Light Industry, Nanjing University of Technology, Nanjing, People's Republic of China
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25
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Dragosits M, Mattanovich D. Adaptive laboratory evolution -- principles and applications for biotechnology. Microb Cell Fact 2013; 12:64. [PMID: 23815749 PMCID: PMC3716822 DOI: 10.1186/1475-2859-12-64] [Citation(s) in RCA: 434] [Impact Index Per Article: 39.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 06/24/2013] [Indexed: 11/19/2022] Open
Abstract
Adaptive laboratory evolution is a frequent method in biological studies to gain insights into the basic mechanisms of molecular evolution and adaptive changes that accumulate in microbial populations during long term selection under specified growth conditions. Although regularly performed for more than 25 years, the advent of transcript and cheap next-generation sequencing technologies has resulted in many recent studies, which successfully applied this technique in order to engineer microbial cells for biotechnological applications. Adaptive laboratory evolution has some major benefits as compared with classical genetic engineering but also some inherent limitations. However, recent studies show how some of the limitations may be overcome in order to successfully incorporate adaptive laboratory evolution in microbial cell factory design. Over the last two decades important insights into nutrient and stress metabolism of relevant model species were acquired, whereas some other aspects such as niche-specific differences of non-conventional cell factories are not completely understood. Altogether the current status and its future perspectives highlight the importance and potential of adaptive laboratory evolution as approach in biotechnological engineering.
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Affiliation(s)
- Martin Dragosits
- Department of Chemistry, University of Natural Resources and Life Sciences, Muthgasse 11, A-1190 Vienna, Austria.
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Genome Sequence of Clostridium tyrobutyricum ATCC 25755, a Butyric Acid-Overproducing Strain. GENOME ANNOUNCEMENTS 2013; 1:1/3/e00308-13. [PMID: 23723404 PMCID: PMC3668012 DOI: 10.1128/genomea.00308-13] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Clostridium tyrobutyricum ATCC 25755 is an efficient producer of butyric acid. Here we report a 3.01-Mb assembly of its genome sequence and other useful information, including the coding sequences (CDSs) responsible for an alternative pathway leading to acetate synthesis as well as a series of membrane transport systems.
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