1
|
Yuan D, Liu B, Jiang L, Chen Y, Xu G, Lin J, Yang L, Lian J, Jiang Y, Ye L, Wu M. XylR Overexpression in Escherichia coli Alleviated Transcriptional Repression by Arabinose and Enhanced Xylitol Bioproduction from Xylose Mother Liquor. Appl Biochem Biotechnol 2024:10.1007/s12010-024-04890-x. [PMID: 38393582 DOI: 10.1007/s12010-024-04890-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2024] [Indexed: 02/25/2024]
Abstract
Xylitol is a polyol widely used in food, pharmaceuticals, and light industries. It is currently produced through the chemical catalytic hydrogenation of xylose and generates xylose mother liquor as a substantial byproduct in the procedure of xylose extraction. If xylose mother liquor could also be efficiently bioconverted to xylitol, the greenness and atom economy of xylitol production would be largely improved. However, xylose mother liquor contains a mixture of glucose, xylose, and arabinose, raising the issue of carbon catabolic repression in its utilization by microbial conversion. Targeting this challenge, the transcriptional activator XylR was overexpressed in a previously constructed xylitol-producing E. coli strain CPH. The resulting strain CPHR produced 16.61 g/L of xylitol in shake-flask cultures from the mixture of corn cob hydrolysate and xylose mother liquor (1:1, v/v) with a xylose conversion rate of 90.1%, which were 2.23 and 2.15 times higher than the starting strain, respectively. Furthermore, XylR overexpression upregulated the expression levels of xylE, xylF, xylG, and xylH genes by 2.08-2.72 times in arabinose-containing medium, suggesting the alleviation of transcriptional repression of xylose transport genes by arabinose. This work lays the foundation for xylitol bioproduction from xylose mother liquor.
Collapse
Affiliation(s)
- Dongxu Yuan
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Bingbing Liu
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Lin Jiang
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Yuhuan Chen
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Gang Xu
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Jianping Lin
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Lirong Yang
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Jiazhang Lian
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Yiqi Jiang
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310058, People's Republic of China.
- School of Biological and Chemical Engineering, NingboTech University, Ningbo, 315100, People's Republic of China.
| | - Lidan Ye
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310058, People's Republic of China.
| | - Mianbin Wu
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310058, People's Republic of China.
- Ningbo Innovation Center, Zhejiang University, Ningbo, 315100, People's Republic of China.
- Zhejiang Key Laboratory of Antifungal Drugs, Taizhou, 318000, People's Republic of China.
| |
Collapse
|
2
|
Yuan D, Liu B, Yuan X, Feng L, Xu X, Zhu J, Chen Z, Xu R, Chen J, Xu G, Lin J, Yang L, Li M, Lian J, Wu M. Multisite Mutation of the Escherichia coli cAMP Receptor Protein: Enhancing Xylitol Biosynthesis by Activating Xylose Catabolism and Improving Strain Tolerance. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023. [PMID: 37921650 DOI: 10.1021/acs.jafc.3c05445] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2023]
Abstract
The bioproduction of xylitol from hemicellulose hydrolysate has good potential for industrial development. However, xylitol productivity has always been limited due to corncob hydrolysate toxicity and glucose catabolic repression. To address these challenges, this work selected the S83 and S128 amino acid residues of the cyclic AMP receptor protein (CRP) as the modification target. By introducing multisite mutation in CRP, this approach successfully enhanced xylose catabolism and improved the strain's tolerance to corncob hydrolysate. The resulting mutant strain, designated as CPH (CRP S83H-S128P), underwent fermentation in a 20 L bioreactor with semicontinuous feeding of corncob hydrolysate. Remarkably, xylitol yield and xylitol productivity for 41 h fermentation were 175 and 4.32 g/L/h, respectively. Therefore, multisite CRP mutation was demonstrated as an efficient global regulatory strategy to effectively improve xylitol productivity from lime-pretreated corncob hydrolysates.
Collapse
Affiliation(s)
- Dongxu Yuan
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310030, PR China
| | - Bingbing Liu
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310030, PR China
| | - Xinsong Yuan
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310030, PR China
- School of Chemistry and Chemical Engineering, Hefei Normal University, Hefei 230601, PR China
| | - Leilei Feng
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310030, PR China
| | - Xudong Xu
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310030, PR China
| | - Jialin Zhu
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310030, PR China
| | - Zhengjie Chen
- Shandong Weiyan Biotechnology Co., Ltd, Binzhou 256660, PR China
| | - Renhao Xu
- Hangzhou No. 14 Middle School, Hangzhou 310006, PR China
| | - Jiao Chen
- Zhejiang Key Laboratory of Antifungal Drugs, Taizhou 318000, PR China
- Haizheng Pharmaceutical Co., Ltd, Taizhou 318000, PR China
| | - Gang Xu
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310030, PR China
| | - Jianping Lin
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310030, PR China
| | - Lirong Yang
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310030, PR China
| | - Mian Li
- Zhejiang Huakang Pharmaceutical Co., Ltd, Quzhou 324302, PR China
| | - Jiazhang Lian
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310030, PR China
| | - Mianbin Wu
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310030, PR China
- Ningbo Research Institute, Zhejiang University, Ningbo 315100, PR China
- Zhejiang Key Laboratory of Antifungal Drugs, Taizhou 318000, PR China
| |
Collapse
|
3
|
Soma Y, Tominaga S, Tokito K, Imado Y, Naka K, Hanai T, Takahashi M, Izumi Y, Bamba T. Trace impurities in sodium phosphate influences the physiological activity of Escherichia coli in M9 minimal medium. Sci Rep 2023; 13:17396. [PMID: 37833342 PMCID: PMC10576033 DOI: 10.1038/s41598-023-44526-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Accepted: 10/09/2023] [Indexed: 10/15/2023] Open
Abstract
In the field of applied microbiology, reproducibility and experimental variability are important factors that influence both basic research as well as process development for industrial applications. Experimental reproducibility and accuracy depend not only on culture conditions such as temperature and aeration but also on raw materials and procedures used for media preparation. The M9 minimal medium is one of the most common synthetic media for culturing Escherichia coli and other bacteria. This synthetic medium can be used to observe and evaluate the physiological activity of microbes under minimal nutritional requirements and determine the limiting factor for the desired phenotype. Although one of the advantages using the M9 medium is that its composition can be modulated, it is difficult to control presence of trace components and impurities from the reagents for preparing this medium. Herein, we showed that trace ingredients present in the reagents used for M9 media preparation affect the bacterial physiological activities (e.g., cell growth, substrate consumption, and byproduct formation). Additionally, we systematically identified the trace ingredient that influenced phenotypic differences. Our results showed that the selection of reagents and accuracy during reagent preparation is important for experimental reproducibility in the field of bio-engineering and systems biology focused on the systematic and continuous development of biomolecular systems (e.g., biorefinery, metabolic engineering, and synthetic biology).
Collapse
Affiliation(s)
- Yuki Soma
- Division of Metabolomics/Mass Spectrometry Center, Medical Research Center for High Depth Omics, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
- Laboratory for Synthetic Biology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, W5-729, 819-0395, Japan
| | - Saki Tominaga
- Division of Metabolomics/Mass Spectrometry Center, Medical Research Center for High Depth Omics, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Kanako Tokito
- Division of Metabolomics/Mass Spectrometry Center, Medical Research Center for High Depth Omics, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Yuri Imado
- Division of Metabolomics/Mass Spectrometry Center, Medical Research Center for High Depth Omics, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Kosuke Naka
- Shimadzu Corporation, 1, Nishinokyo-Kuwabara-cho, Nakagyo-ku, Kyoto, 604-8511, Japan
| | - Taizo Hanai
- Laboratory for Synthetic Biology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, W5-729, 819-0395, Japan
| | - Masatomo Takahashi
- Division of Metabolomics/Mass Spectrometry Center, Medical Research Center for High Depth Omics, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Yoshihiro Izumi
- Division of Metabolomics/Mass Spectrometry Center, Medical Research Center for High Depth Omics, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Takeshi Bamba
- Division of Metabolomics/Mass Spectrometry Center, Medical Research Center for High Depth Omics, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
| |
Collapse
|
4
|
Yuan X, Gao S, Tan Y, Cao J, Yang S, Zheng B. Production of red yeast rice rich in monacolin K by variable temperature solid fermentation of Monascus purpureus. RSC Adv 2023; 13:27303-27308. [PMID: 37705986 PMCID: PMC10496031 DOI: 10.1039/d3ra04374f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 09/04/2023] [Indexed: 09/15/2023] Open
Abstract
Hypercholesterolemia represents a serious public health problem as it significantly increases the risk of developing cardiovascular diseases. Monacolin K (MK) in red yeast rice is an active compound that can effectively lower plasma cholesterol. To enhance the yield of MK in solid state fermentation of Monascus purpureus HNU01, the effects of different variables were systematically examined in single-factor experiments. The optimal conditions for the production of red yeast rice rich in MK were as follows: initial pH value 5.5, initial moisture content 40% w/w, glucose 50 g L-1, peptone 20 g L-1, MgSO4 0.5 g L-1, KH2PO4 1 g L-1, variable temperature fermentation (30 °C for the first 3 days and then 24 °C for 15 days), total fermentation time of 18 days, and additional water added at day 4 at 10% w/w. Under the above optimized conditions, the MK content of red yeast rice produced by fermentation was 9.5 mg g-1. No citrinin was detected in any of the batches of fermentation products. The results will be useful for the large-scale production of high-quality red yeast rice with health benefits for consumers.
Collapse
Affiliation(s)
- Xinsong Yuan
- School of Chemistry and Pharmaceutical Engineering, Hefei Normal University Hefei 230601 China
| | - Shan Gao
- School of Chemistry and Pharmaceutical Engineering, Hefei Normal University Hefei 230601 China
| | - Yudie Tan
- School of Chemistry and Pharmaceutical Engineering, Hefei Normal University Hefei 230601 China
| | - Jiyun Cao
- School of Chemistry and Pharmaceutical Engineering, Hefei Normal University Hefei 230601 China
| | - Shiwei Yang
- School of Chemistry and Pharmaceutical Engineering, Hefei Normal University Hefei 230601 China
| | - Bin Zheng
- School of Chemistry and Pharmaceutical Engineering, Hefei Normal University Hefei 230601 China
| |
Collapse
|
5
|
Liang P, Cao M, Li J, Wang Q, Dai Z. Expanding sugar alcohol industry: Microbial production of sugar alcohols and associated chemocatalytic derivatives. Biotechnol Adv 2023; 64:108105. [PMID: 36736865 DOI: 10.1016/j.biotechadv.2023.108105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Revised: 01/28/2023] [Accepted: 01/29/2023] [Indexed: 02/04/2023]
Abstract
Sugar alcohols are polyols that are widely employed in the production of chemicals, pharmaceuticals, and food products. Chemical synthesis of polyols, however, is complex and necessitates the use of hazardous compounds. Therefore, the use of microbes to produce polyols has been proposed as an alternative to traditional synthesis strategies. Many biotechnological approaches have been described to enhancing sugar alcohols production and microbe-mediated sugar alcohol production has the potential to benefit from the availability of inexpensive substrate inputs. Among of them, microbe-mediated erythritol production has been implemented in an industrial scale, but microbial growth and substrate conversion rates are often limited by harsh environmental conditions. In this review, we focused on xylitol, mannitol, sorbitol, and erythritol, the four representative sugar alcohols. The main metabolic engineering strategies, such as regulation of key genes and cofactor balancing, for improving the production of these sugar alcohols were reviewed. The feasible strategies to enhance the stress tolerance of chassis cells, especially thermotolerance, were also summarized. Different low-cost substrates like glycerol, molasses, cellulose hydrolysate, and CO2 employed for producing these sugar alcohols were presented. Given the value of polyols as precursor platform chemicals that can be leveraged to produce a diverse array of chemical products, we not only discuss the challenges encountered in the above parts, but also envisioned the development of their derivatives for broadening the application of sugar alcohols.
Collapse
Affiliation(s)
- Peixin Liang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, China
| | - Mingfeng Cao
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Jing Li
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, China; College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Qinhong Wang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, China.
| | - Zongjie Dai
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, China.
| |
Collapse
|
6
|
Yuan X, Cao J, Wang R, Han Y, Zhu J, Lin J, Yang L, Wu M. Genetically Engineering Escherichia coli to Produce Xylitol from Corncob Hydrolysate without Lime Detoxification. Molecules 2023; 28:1550. [PMID: 36838538 PMCID: PMC9967598 DOI: 10.3390/molecules28041550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 02/02/2023] [Accepted: 02/03/2023] [Indexed: 02/09/2023] Open
Abstract
Before fermentation with hemicellulosic hydrolysate as a substrate, it is generally necessary to detoxify the toxic substances that are harmful to microorganism growth. Cyclic AMP receptor protein (CRP) is a global regulator, and mutation of its key sites may have an important impact on E. coli virulence tolerance. Using corncob hydrolysate without ion-exchange or lime detoxification as the substrate, shake flask fermentation experiments showed that CRP mutant IS5-dG (I112L, T127G, A144T) produced 18.4 g/L of xylitol within 34 h, and the OD600 was 9.7 at 24 h; these values were 41.5% and 21.3% higher than those of the starting strain, IS5-d, respectively. This mutant produced 82 g/L of xylitol from corncob hydrolysate without ion-exchange or lime detoxification during fed-batch fermentation in a 15-L bioreactor, with a productivity of 1.04 g/L/h; these values were 173% and 174% higher than the starting strain, respectively. To our knowledge, this is the highest xylitol concentration and productivity produced by microbial fermentation using completely non-detoxified hemicellulosic hydrolysate as the substrate to date. This study also showed that alkali neutralization, high temperature sterilization, and fermentation of the hydrolysate had important effects on the xylose loss rate and xylitol production.
Collapse
Affiliation(s)
- Xinsong Yuan
- School of Chemistry and Chemical Engineering, Hefei Normal University, Hefei 230601, China
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Jiyun Cao
- School of Chemistry and Chemical Engineering, Hefei Normal University, Hefei 230601, China
| | - Rui Wang
- School of Chemistry and Chemical Engineering, Hefei Normal University, Hefei 230601, China
| | - Yu Han
- School of Chemistry and Chemical Engineering, Hefei Normal University, Hefei 230601, China
| | - Jinmiao Zhu
- School of Chemistry and Chemical Engineering, Hefei Normal University, Hefei 230601, China
| | - Jianping Lin
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
- Ningbo Research Institute, Zhejiang University, Ningbo 315100, China
| | - Lirong Yang
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Mianbin Wu
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
- Ningbo Research Institute, Zhejiang University, Ningbo 315100, China
| |
Collapse
|
7
|
Biological production of xylitol by using nonconventional microbial strains. World J Microbiol Biotechnol 2022; 38:249. [DOI: 10.1007/s11274-022-03437-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 10/07/2022] [Indexed: 10/31/2022]
|
8
|
Lekshmi Sundar MS, Madhavan Nampoothiri K. An overview of the metabolically engineered strains and innovative processes used for the value addition of biomass derived xylose to xylitol and xylonic acid. BIORESOURCE TECHNOLOGY 2022; 345:126548. [PMID: 34906704 DOI: 10.1016/j.biortech.2021.126548] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 12/06/2021] [Accepted: 12/07/2021] [Indexed: 06/14/2023]
Abstract
Xylose, the most abundant pentose sugar of the hemicellulosic fraction of lignocellulosic biomass, has to be utilized rationally for the commercial viability of biorefineries. An effective pre-treatment strategy for the release of xylose from the biomass and an appropriate microbe of the status of an Industrial strain for the utilization of this pentose sugar are key challenges which need special attention for the economic success of the biomass value addition to chemicals. Xylitol and xylonic acid, the alcohol and acid derivatives of xylose are highly demanded commodity chemicals globally with plenty of applications in the food and pharma industries. This review emphasis on the natural and metabolically engineered strains utilizing xylose and the progressive and innovative fermentation strategies for the production and subsequent recovery of the above said chemicals from pre-treated biomass medium.
Collapse
Affiliation(s)
- M S Lekshmi Sundar
- Microbial Processes and Technology Division, CSIR - National Institute for Interdisciplinary Science and Technology (NIIST), Thiruvananthapuram 695019, Kerala, India; Academy of Scientific and Innovative Research (AcSIR), CSIR-HRDG Campus, Ghaziabad, Uttar Pradesh 201002, India
| | - K Madhavan Nampoothiri
- Microbial Processes and Technology Division, CSIR - National Institute for Interdisciplinary Science and Technology (NIIST), Thiruvananthapuram 695019, Kerala, India.
| |
Collapse
|
9
|
Guo Q, Ullah I, Zheng LJ, Gao XQ, Liu CY, Zheng HD, Fan LH, Deng L. Intelligent self-control of carbon metabolic flux in SecY-engineered Escherichia coli for xylitol biosynthesis from xylose-glucose mixtures. Biotechnol Bioeng 2021; 119:388-398. [PMID: 34837379 DOI: 10.1002/bit.28002] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 11/19/2021] [Accepted: 11/23/2021] [Indexed: 01/31/2023]
Abstract
Xylitol is a salutary sugar substitute that has been widely used in the food, pharmaceutical, and chemical industries. Co-fermentation of xylose and glucose by metabolically engineered cell factories is a promising alternative to chemical hydrogenation of xylose for commercial production of xylitol. Here, we engineered a mutant of SecY protein-translocation channel (SecY [ΔP]) in xylitol-producing Escherichia coli JM109 (DE3) as a passageway for xylose uptake. It was found that SecY (ΔP) channel could rapidly transport xylose without being interfered by XylB-catalyzed synthesis of xylitol-phosphate, which is impossible for native XylFGH and XylE transporters. More importantly, with the coaction of SecY (ΔP) channel and carbon catabolite repression (CCR), the flux of xylose to the pentose phosphate (PP) pathway and the xylitol synthesis pathway in E. coli could be automatically controlled in response to glucose, thereby ensuring that the mutant cells were able to fully utilize sugars with high xylitol yields. The E. coli cell factory developed in this study has been proven to be applicable to a broad range of xylose-glucose mixtures, which is conducive to simplifying the mixed-sugar fermentation process for efficient and economical production of xylitol.
Collapse
Affiliation(s)
- Qiang Guo
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People's Republic of China
- College of Chemical Engineering, Fujian Engineering Research Center of Advanced Manufacturing Technology for Fine Chemicals, Fuzhou University, Fuzhou, People's Republic of China
| | - Irfan Ullah
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People's Republic of China
| | - Ling-Jie Zheng
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People's Republic of China
- College of Chemical Engineering, Fujian Engineering Research Center of Advanced Manufacturing Technology for Fine Chemicals, Fuzhou University, Fuzhou, People's Republic of China
| | - Xin-Quan Gao
- College of Chemical Engineering, Fujian Engineering Research Center of Advanced Manufacturing Technology for Fine Chemicals, Fuzhou University, Fuzhou, People's Republic of China
| | - Chen-Yang Liu
- Qingyuan Innovation Laboratory, Fuzhou University, Quanzhou, People's Republic of China
| | - Hui-Dong Zheng
- College of Chemical Engineering, Fujian Engineering Research Center of Advanced Manufacturing Technology for Fine Chemicals, Fuzhou University, Fuzhou, People's Republic of China
- Qingyuan Innovation Laboratory, Fuzhou University, Quanzhou, People's Republic of China
| | - Li-Hai Fan
- College of Chemical Engineering, Fujian Engineering Research Center of Advanced Manufacturing Technology for Fine Chemicals, Fuzhou University, Fuzhou, People's Republic of China
- Qingyuan Innovation Laboratory, Fuzhou University, Quanzhou, People's Republic of China
| | - Li Deng
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People's Republic of China
| |
Collapse
|
10
|
Xylose Metabolism in Bacteria—Opportunities and Challenges towards Efficient Lignocellulosic Biomass-Based Biorefineries. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11178112] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In a sustainable society based on circular economy, the use of waste lignocellulosic biomass (LB) as feedstock for biorefineries is a promising solution, since LB is the world’s most abundant renewable and non-edible raw material. LB is available as a by-product from agricultural and forestry processes, and its main components are cellulose, hemicellulose, and lignin. Following suitable physical, enzymatic, and chemical steps, the different fractions can be processed and/or converted to value-added products such as fuels and biochemicals used in several branches of industry through the implementation of the biorefinery concept. Upon hydrolysis, the carbohydrate-rich fraction may comprise several simple sugars (e.g., glucose, xylose, arabinose, and mannose) that can then be fed to fermentation units. Unlike pentoses, glucose and other hexoses are readily processed by microorganisms. Some wild-type and genetically modified bacteria can metabolize xylose through three different main pathways of metabolism: xylose isomerase pathway, oxidoreductase pathway, and non-phosphorylative pathway (including Weimberg and Dahms pathways). Two of the commercially interesting intermediates of these pathways are xylitol and xylonic acid, which can accumulate in the medium either through manipulation of the culture conditions or through genetic modification of the bacteria. This paper provides a state-of-the art perspective regarding the current knowledge on xylose transport and metabolism in bacteria as well as envisaged strategies to further increase xylose conversion into valuable products.
Collapse
|
11
|
Yuan X, Mao Y, Tu S, Lin J, Shen H, Yang L, Wu M. Increasing NADPH Availability for Xylitol Production via Pentose-Phosphate-Pathway Gene Overexpression and Embden-Meyerhof-Parnas-Pathway Gene Deletion in Escherichia coli. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:9625-9631. [PMID: 34382797 DOI: 10.1021/acs.jafc.1c03283] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Cofactor availability is often a rate-limiting factor in the bioconversion of xylose to xylitol. The overexpression of pentose phosphate pathway genes and the deletion of Embden-Meyerhof-Parnas pathway genes can modulate the glucose metabolic flux and increase the intracellular NADPH supply, enabling Escherichia coli cells to produce xylitol from corncob hydrolysates. The effects of zwf and/or gnd overexpression and pfkA, pfkB, and/or pgi deletion on the intracellular redox environment and xylitol production were examined. The NADPH-enhanced strain 2bpgi produced 162 g/L xylitol from corncob hydrolysates after a 76 h fed-batch fermentation in a 15 L bioreactor, which was 13.3% greater than the 143 g/L xylitol produced by the IS5-d control strain. Additionally, the xylitol productivity and xylitol yield per glucose for 2bpgi were 2.13 g/L/h and 2.50 g/g, respectively. Thus, the genetic modifications in 2bpgi significantly enhanced NADPH regeneration, making 2bpgi a potentially useful strain for the industrial-scale production of xylitol from detoxified corncob hydrolysates.
Collapse
Affiliation(s)
- Xinsong Yuan
- Key Laboratory of Biomass Chemical Engineering of the Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, PR China
- School of Chemistry and Chemical Engineering, Hefei Normal University, Hefei 230601, PR China
| | - Yudi Mao
- Key Laboratory of Biomass Chemical Engineering of the Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, PR China
| | - Shuai Tu
- School of Chemistry and Chemical Engineering, Hefei Normal University, Hefei 230601, PR China
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Jianping Lin
- Key Laboratory of Biomass Chemical Engineering of the Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, PR China
| | - Huahao Shen
- Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, PR China
| | - Lirong Yang
- Key Laboratory of Biomass Chemical Engineering of the Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, PR China
| | - Mianbin Wu
- Key Laboratory of Biomass Chemical Engineering of the Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, PR China
- Ningbo Research Institute, Zhejiang University, Ningbo 315100, PR China
| |
Collapse
|
12
|
Xiang S, Ye K, Li M, Ying J, Wang H, Han J, Shi L, Xiao J, Shen Y, Feng X, Bao X, Zheng Y, Ge Y, Zhang Y, Liu C, Chen J, Chen Y, Tian S, Zhu X. Xylitol enhances synthesis of propionate in the colon via cross-feeding of gut microbiota. MICROBIOME 2021; 9:62. [PMID: 33736704 PMCID: PMC7977168 DOI: 10.1186/s40168-021-01029-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 02/05/2021] [Indexed: 05/12/2023]
Abstract
BACKGROUND Xylitol, a white or transparent polyol or sugar alcohol, is digestible by colonic microorganisms and promotes the proliferation of beneficial bacteria and the production of short-chain fatty acids (SCFAs), but the mechanism underlying these effects remains unknown. We studied mice fed with 0%, 2% (2.17 g/kg/day), or 5% (5.42 g/kg/day) (weight/weight) xylitol in their chow for 3 months. In addition to the in vivo digestion experiments in mice, 3% (weight/volume) (0.27 g/kg/day for a human being) xylitol was added to a colon simulation system (CDMN) for 7 days. We performed 16S rRNA sequencing, beneficial metabolism biomarker quantification, metabolome, and metatranscriptome analyses to investigate the prebiotic mechanism of xylitol. The representative bacteria related to xylitol digestion were selected for single cultivation and co-culture of two and three bacteria to explore the microbial digestion and utilization of xylitol in media with glucose, xylitol, mixed carbon sources, or no-carbon sources. Besides, the mechanisms underlying the shift in the microbial composition and SCFAs were explored in molecular contexts. RESULTS In both in vivo and in vitro experiments, we found that xylitol did not significantly influence the structure of the gut microbiome. However, it increased all SCFAs, especially propionate in the lumen and butyrate in the mucosa, with a shift in its corresponding bacteria in vitro. Cross-feeding, a relationship in which one organism consumes metabolites excreted by the other, was observed among Lactobacillus reuteri, Bacteroides fragilis, and Escherichia coli in the utilization of xylitol. At the molecular level, we revealed that xylitol dehydrogenase (EC 1.1.1.14), xylulokinase (EC 2.7.1.17), and xylulose phosphate isomerase (EC 5.1.3.1) were key enzymes in xylitol metabolism and were present in Bacteroides and Lachnospiraceae. Therefore, they are considered keystone bacteria in xylitol digestion. Also, xylitol affected the metabolic pathway of propionate, significantly promoting the transcription of phosphate acetyltransferase (EC 2.3.1.8) in Bifidobacterium and increasing the production of propionate. CONCLUSIONS Our results revealed that those key enzymes for xylitol digestion from different bacteria can together support the growth of micro-ecology, but they also enhanced the concentration of propionate, which lowered pH to restrict relative amounts of Escherichia and Staphylococcus. Based on the cross-feeding and competition among those bacteria, xylitol can dynamically balance proportions of the gut microbiome to promote enzymes related to xylitol metabolism and SCFAs. Video Abstract.
Collapse
Affiliation(s)
- Shasha Xiang
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018 China
| | - Kun Ye
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018 China
| | - Mian Li
- Zhejiang Huakang Pharmaceutical Co., Ltd., Kaihua, 324302 China
| | - Jian Ying
- Nutrition and Health Research Institute, COFCO Ltd., Beijing, 102209 China
| | - Huanhuan Wang
- School of Medicine, Hangzhou Normal University, Hangzhou, 310018 China
- Laboratory of Aging and Cancer Biology of Zhejiang Province, Hangzhou Normal University, Hangzhou, 311121 China
| | - Jianzhong Han
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018 China
| | - Lihua Shi
- Zhejiang Huakang Pharmaceutical Co., Ltd., Kaihua, 324302 China
| | - Jie Xiao
- Nutrition and Health Research Institute, COFCO Ltd., Beijing, 102209 China
| | - Yubiao Shen
- Yangtze Delta Institute of Tsinghua University, Jiaxing, 314000 China
| | - Xiao Feng
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018 China
| | - Xuan Bao
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018 China
| | - Yiqing Zheng
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018 China
| | - Yin Ge
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018 China
| | - Yalin Zhang
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018 China
| | - Chang Liu
- School of Food Science and Technology, Jiangnan University, Wuxi, 214122 China
| | - Jie Chen
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018 China
| | - Yuewen Chen
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018 China
| | - Shiyi Tian
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018 China
| | - Xuan Zhu
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018 China
| |
Collapse
|
13
|
Bañares AB, Nisola GM, Valdehuesa KNG, Lee WK, Chung WJ. Engineering of xylose metabolism in Escherichia coli for the production of valuable compounds. Crit Rev Biotechnol 2021; 41:649-668. [PMID: 33563072 DOI: 10.1080/07388551.2021.1873243] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The lignocellulosic sugar d-xylose has recently gained prominence as an inexpensive alternative substrate for the production of value-added compounds using genetically modified organisms. Among the prokaryotes, Escherichia coli has become the de facto host for the development of engineered microbial cell factories. The favored status of E. coli resulted from a century of scientific explorations leading to a deep understanding of its systems. However, there are limited literature reviews that discuss engineered E. coli as a platform for the conversion of d-xylose to any target compounds. Additionally, available critical review articles tend to focus on products rather than the host itself. This review aims to provide relevant and current information about significant advances in the metabolic engineering of d-xylose metabolism in E. coli. This focusses on unconventional and synthetic d-xylose metabolic pathways as several review articles have already discussed the engineering of native d-xylose metabolism. This paper, in particular, is essential to those who are working on engineering of d-xylose metabolism using E. coli as the host.
Collapse
Affiliation(s)
- Angelo B Bañares
- Environmental Waste Recycle Institute (EWRI), Department of Energy Science and Technology (DEST), Myongji University, Yongin, Gyeonggi, South Korea
| | - Grace M Nisola
- Environmental Waste Recycle Institute (EWRI), Department of Energy Science and Technology (DEST), Myongji University, Yongin, Gyeonggi, South Korea
| | - Kris N G Valdehuesa
- Environmental Waste Recycle Institute (EWRI), Department of Energy Science and Technology (DEST), Myongji University, Yongin, Gyeonggi, South Korea
| | - Won-Keun Lee
- Division of Bioscience and Bioinformatics, Myongji University, Yongin, Gyeonggi, South Korea
| | - Wook-Jin Chung
- Environmental Waste Recycle Institute (EWRI), Department of Energy Science and Technology (DEST), Myongji University, Yongin, Gyeonggi, South Korea
| |
Collapse
|
14
|
Li S, Ye Z, Moreb EA, Hennigan JN, Castellanos DB, Yang T, Lynch MD. Dynamic control over feedback regulatory mechanisms improves NADPH flux and xylitol biosynthesis in engineered E. coli. Metab Eng 2021; 64:26-40. [PMID: 33460820 DOI: 10.1016/j.ymben.2021.01.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 12/23/2020] [Accepted: 01/10/2021] [Indexed: 12/24/2022]
Abstract
We report improved NADPH flux and xylitol biosynthesis in engineered E. coli. Xylitol is produced from xylose via an NADPH dependent reductase. We utilize 2-stage dynamic metabolic control to compare two approaches to optimize xylitol biosynthesis, a stoichiometric approach, wherein competitive fluxes are decreased, and a regulatory approach wherein the levels of key regulatory metabolites are reduced. The stoichiometric and regulatory approaches lead to a 20-fold and 90-fold improvement in xylitol production, respectively. Strains with reduced levels of enoyl-ACP reductase and glucose-6-phosphate dehydrogenase, led to altered metabolite pools resulting in the activation of the membrane bound transhydrogenase and an NADPH generation pathway, consisting of pyruvate ferredoxin oxidoreductase coupled with NADPH dependent ferredoxin reductase, leading to increased NADPH fluxes, despite a reduction in NADPH pools. These strains produced titers of 200 g/L of xylitol from xylose at 86% of theoretical yield in instrumented bioreactors. We expect dynamic control over the regulation of the membrane bound transhydrogenase as well as NADPH production through pyruvate ferredoxin oxidoreductase to broadly enable improved NADPH dependent bioconversions or production via NADPH dependent metabolic pathways.
Collapse
Affiliation(s)
- Shuai Li
- Department of Chemistry, Duke University, USA
| | - Zhixia Ye
- Department of Biomedical Engineering, Duke University, USA
| | - Eirik A Moreb
- Department of Biomedical Engineering, Duke University, USA
| | | | | | - Tian Yang
- Department of Biomedical Engineering, Duke University, USA
| | | |
Collapse
|
15
|
Prabhu AA, Bosakornranut E, Amraoui Y, Agrawal D, Coulon F, Vivekanand V, Thakur VK, Kumar V. Enhanced xylitol production using non-detoxified xylose rich pre-hydrolysate from sugarcane bagasse by newly isolated Pichia fermentans. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:209. [PMID: 33375948 PMCID: PMC7772924 DOI: 10.1186/s13068-020-01845-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 11/28/2020] [Indexed: 05/09/2023]
Abstract
BACKGROUND Integrated management of hemicellulosic fraction and its economical transformation to value-added products is the key driver towards sustainable lignocellulosic biorefineries. In this aspect, microbial cell factories are harnessed for the sustainable production of commercially viable biochemicals by valorising C5 and C6 sugars generated from agro-industrial waste. However, in the terrestrial ecosystem, microbial systems can efficiently consume glucose. On the contrary, pentose sugars are less preferred carbon source as most of the microbes lack metabolic pathway for their utilization. The effective utilization of both pentose and hexose sugars is key for economical biorefinery. RESULTS Bioprospecting the food waste and selective enrichment on xylose-rich medium led to screening and isolation of yeast which was phylogenetically identified as Pichia fermentans. The newly isolated xylose assimilating yeast was explored for xylitol production. The wild type strain robustly grew on xylose and produced xylitol with > 40% conversion yield. Chemical mutagenesis of isolated yeast with ethyl methanesulphonate (EMS) yielded seven mutants. The mutant obtained after 15 min EMS exposure, exhibited best xylose bioconversion efficiency. This mutant under shake flask conditions produced maximum xylitol titer and yield of 34.0 g/L and 0.68 g/g, respectively. However, under the same conditions, the control wild type strain accumulated 27.0 g/L xylitol with a conversion yield of 0.45 g/g. Improved performance of the mutant was attributed to 34.6% activity enhancement in xylose reductase with simultaneous reduction of xylitol dehydrogenase activity by 22.9%. Later, the culture medium was optimized using statistical design and validated at shake flask and bioreactor level. Bioreactor studies affirmed the competence of the mutant for xylitol accumulation. The xylitol titer and yield obtained with pure xylose were 98.9 g/L and 0.67 g/g, respectively. In comparison, xylitol produced using non-detoxified xylose rich pre-hydrolysate from sugarcane bagasse was 79.0 g/L with an overall yield of 0.54 g/g. CONCLUSION This study demonstrates the potential of newly isolated P. fermentans in successfully valorising the hemicellulosic fraction for the sustainable xylitol production.
Collapse
Affiliation(s)
- Ashish A Prabhu
- School of Water, Energy and Environment, Cranfield University, Cranfield, MK43 0AL, UK
| | - Ekkarin Bosakornranut
- School of Water, Energy and Environment, Cranfield University, Cranfield, MK43 0AL, UK
| | - Yassin Amraoui
- School of Water, Energy and Environment, Cranfield University, Cranfield, MK43 0AL, UK
| | - Deepti Agrawal
- Biochemistry and Biotechnology Area, Material Resource Efficiency Division, CSIR-Indian Institute of Petroleum, Mohkampur, Dehradun, 248005, India
| | - Frederic Coulon
- School of Water, Energy and Environment, Cranfield University, Cranfield, MK43 0AL, UK
| | - Vivekanand Vivekanand
- Centre for Energy and Environment, Malaviya National Institute of Technology, Jaipur, Rajasthan, 302017, India
| | - Vijay Kumar Thakur
- Biorefining and Advanced Materials Research Centre, Scotland's Rural College (SRUC), Edinburgh, UK
| | - Vinod Kumar
- School of Water, Energy and Environment, Cranfield University, Cranfield, MK43 0AL, UK.
| |
Collapse
|
16
|
Biosynthesis of myo-inositol in Escherichia coli by engineering myo-inositol-1-phosphate pathway. Biochem Eng J 2020. [DOI: 10.1016/j.bej.2020.107792] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
|
17
|
Biovalorisation of crude glycerol and xylose into xylitol by oleaginous yeast Yarrowia lipolytica. Microb Cell Fact 2020; 19:121. [PMID: 32493445 PMCID: PMC7271524 DOI: 10.1186/s12934-020-01378-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 05/25/2020] [Indexed: 11/29/2022] Open
Abstract
Background Xylitol is a commercially important chemical with multiple applications in the food and pharmaceutical industries. According to the US Department of Energy, xylitol is one of the top twelve platform chemicals that can be produced from biomass. The chemical method for xylitol synthesis is however, expensive and energy intensive. In contrast, the biological route using microbial cell factories offers a potential cost-effective alternative process. The bioprocess occurs under ambient conditions and makes use of biocatalysts and biomass which can be sourced from renewable carbon originating from a variety of cheap waste feedstocks. Result In this study, biotransformation of xylose to xylitol was investigated using Yarrowia lipolytica, an oleaginous yeast which was firstly grown on a glycerol/glucose for screening of co-substrate, followed by media optimisation in shake flask, scale up in bioreactor and downstream processing of xylitol. A two-step medium optimization was employed using central composite design and artificial neural network coupled with genetic algorithm. The yeast amassed a concentration of 53.2 g/L xylitol using pure glycerol (PG) and xylose with a bioconversion yield of 0.97 g/g. Similar results were obtained when PG was substituted with crude glycerol (CG) from the biodiesel industry (titer: 50.5 g/L; yield: 0.92 g/g). Even when xylose from sugarcane bagasse hydrolysate was used as opposed to pure xylose, a xylitol yield of 0.54 g/g was achieved. Xylitol was successfully crystallized from PG/xylose and CG/xylose fermentation broths with a recovery of 39.5 and 35.3%, respectively. Conclusion To the best of the author’s knowledge, this study demonstrates for the first time the potential of using Y. lipolytica as a microbial cell factory for xylitol synthesis from inexpensive feedstocks. The results obtained are competitive with other xylitol producing organisms.![]()
Collapse
|
18
|
Fan ES, Lu KW, Wen RC, Shen CR. Photosynthetic Reduction of Xylose to Xylitol Using Cyanobacteria. Biotechnol J 2020; 15:e1900354. [PMID: 32388928 DOI: 10.1002/biot.201900354] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 04/30/2020] [Indexed: 12/13/2022]
Abstract
Photosynthetic generation of reducing power makes cyanobacteria an attractive host for biochemical reduction compared to cell-free and heterotrophic systems, which require burning of additional resources for the supply of reducing equivalent. Here, using xylitol synthesis as an example, efficient uptake and reduction of xylose photoautotrophically in Synechococcus elongatus PCC7942 are demonstrated upon introduction of an effective xylose transporter from Escherichia coli (Ec-XylE) and the NADPH-dependent xylose reductase from Candida boidinii (Cb-XR). Simultaneous activation of xylose uptake and matching of cofactor specificity enabled an average xylitol yield of 0.9 g g-1 xylose and a maximum productivity of about 0.15 g L-1 day-1 OD-1 with increased level of xylose supply. While long-term cellular maintenance still appears challenging, high-density conversion of xylose to xylitol using concentrated resting cell further pushes the titer of xylitol formation to 33 g L-1 in six days with 85% of maximum theoretical yield. While the results show that the unknown dissipation of xylose can be minimized when coupled to a strong reaction outlet, it remains to be the major hurdle hampering the yield despite the reported inability of cyanobacteria to metabolize xylose.
Collapse
Affiliation(s)
- Eric S Fan
- Department of Chemical Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu, ROC 30013, Taiwan
| | - Ken W Lu
- Department of Chemical Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu, ROC 30013, Taiwan
| | - Rex C Wen
- Department of Chemical Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu, ROC 30013, Taiwan
| | - Claire R Shen
- Department of Chemical Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu, ROC 30013, Taiwan
| |
Collapse
|
19
|
Su B, Song D, Zhu H. Homology-dependent recombination of large synthetic pathways into E. coli genome via λ-Red and CRISPR/Cas9 dependent selection methodology. Microb Cell Fact 2020; 19:108. [PMID: 32448328 PMCID: PMC7245811 DOI: 10.1186/s12934-020-01360-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 04/30/2020] [Indexed: 01/01/2023] Open
Abstract
Background Metabolic engineering frequently needs genomic integration of many heterologous genes for biosynthetic pathway assembly. Despite great progresses in genome editing for the model microorganism Escherichia coli, the integration of large pathway into genome for stabilized chemical production is still challenging compared with small DNA integration. Results We have developed a λ-Red assisted homology-dependent recombination for large synthetic pathway integration in E. coli. With this approach, we can integrate as large as 12 kb DNA module into the chromosome of E. coli W3110 in a single step. The efficiency of this method can reach 100%, thus markedly improve the integration efficiency and overcome the limitation of the integration size adopted the common method. Furthermore, the limiting step in the methylerythritol 4-phosphate (MEP) pathway and lycopene synthetic pathway were integrated into the W3110 genome using our system. Subsequently, the yields of the final strain were increased 106 and 4.4-fold compared to the initial strain and the reference strain, respectively. Conclusions In addition to pre-existing method, our system presents an optional strategy for avoiding using plasmids and a valuable tool for large synthetic pathway assembly in E. coli.
Collapse
Affiliation(s)
- Buli Su
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Microbial Culture Collection Center (GDMCC), Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, 510070, People's Republic of China
| | - Dandan Song
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Microbial Culture Collection Center (GDMCC), Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, 510070, People's Republic of China
| | - Honghui Zhu
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Microbial Culture Collection Center (GDMCC), Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, 510070, People's Republic of China.
| |
Collapse
|
20
|
Su B, Song D, Zhu H. Metabolic Engineering of Saccharomyces cerevisiae for Enhanced Carotenoid Production From Xylose-Glucose Mixtures. Front Bioeng Biotechnol 2020; 8:435. [PMID: 32478054 PMCID: PMC7240070 DOI: 10.3389/fbioe.2020.00435] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 04/15/2020] [Indexed: 01/31/2023] Open
Abstract
Co-utilization of xylose and glucose from lignocellulosic biomass is an economically feasible bioprocess for chemical production. Many strategies have been implemented for efficiently assimilating xylose which is one of the predominant sugars of lignocellulosic biomass. However, there were few reports about engineering Saccharomyces cerevisiae for carotenoid production from xylose-glucose mixtures. Herein, we developed a platform for facilitating carotenoid production in S. cerevisiae by fermentation of xylose-glucose mixtures. Firstly, a xylose assimilation pathway with mutant xylose reductase (XYL1m), xylitol dehydrogenase (XYL2), and xylulokinase (XK) was constructed for utilizing xylose. Then, introduction of phosphoketolase (PK) pathway, deletion of Pho13 and engineering yeast hexose transporter Gal2 were conducted to improve carotenoid yields. The final strain SC105 produced a 1.6-fold higher production from mixed sugars than that from glucose in flask culture. In fed-batch fermentation with continuous feeding of mixed sugars, carotenoid production represented a 2.6-fold higher. To the best of our knowledge, this is the first report that S. cerevisiae was engineered to utilize xylose-glucose mixtures for carotenoid production with a considerable high yield. The present study exhibits a promising advantage of xylose-glucose mixtures assimilating strain as an industrial carotenoid producer from lignocellulosic biomass.
Collapse
Affiliation(s)
- Buli Su
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Microbial Culture Collection Center (GDMCC), Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Dandan Song
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Microbial Culture Collection Center (GDMCC), Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Honghui Zhu
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Microbial Culture Collection Center (GDMCC), Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| |
Collapse
|
21
|
Gao C, Guo L, Ding Q, Hu G, Ye C, Liu J, Chen X, Liu L. Dynamic consolidated bioprocessing for direct production of xylonate and shikimate from xylan by Escherichia coli. Metab Eng 2020; 60:128-137. [PMID: 32315760 DOI: 10.1016/j.ymben.2020.04.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 02/21/2020] [Accepted: 04/01/2020] [Indexed: 12/18/2022]
Abstract
Numerous value-added chemicals can be produced using xylan as a feedstock. However, the product yields are limited by low xylan utilization efficiency, as well as by carbon flux competition between biomass production and biosynthesis. Herein, a dynamic consolidated bioprocessing strategy was developed, which coupled xylan utilization and yield optimization modules. Specifically, we achieved the efficient conversion of xylan to valuable chemicals in a fully consolidated manner by optimizing the expression level of xylanases and xylose transporter in the xylan utilization module. Moreover, a cell density-dependent, and Cre-triggered dynamic system that enabled the dynamic decoupling of biosynthesis and biomass production was constructed in the yield optimization module. The final shake flask-scale titers of xylonate, produced through an exogenous pathway, and shikimate, produced through an endogenous pathway, reached 16.85 and 3.2 g L-1, respectively. This study not only provides an efficient microbial platform for the utilization of xylan, but also opens up the possibility for the large-scale production of high value-added chemicals from renewable feedstocks.
Collapse
Affiliation(s)
- Cong Gao
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Liang Guo
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Qiang Ding
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Guipeng Hu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Chao Ye
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Jia Liu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Xiulai Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Liming Liu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China; National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, 214122, China.
| |
Collapse
|
22
|
Combination of the CRP mutation and ptsG deletion in Escherichia coli to efficiently synthesize xylitol from corncob hydrolysates. Appl Microbiol Biotechnol 2020; 104:2039-2050. [PMID: 31950219 DOI: 10.1007/s00253-019-10324-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 12/05/2019] [Accepted: 12/15/2019] [Indexed: 12/16/2022]
Abstract
The biotechnology-based production of xylitol has received widespread attention because it can use cheap and renewable lignocellulose as a raw material, thereby decreasing costs and pollution. The simultaneous use of various sugars in lignocellulose hydrolysates is a primary prerequisite for efficient xylitol production. In this study, a ΔptsG and crp* combinatorial strategy was used to generate Escherichia coli W3110 strain IS5-dI, which completely eliminated glucose repression and simultaneously used glucose and xylose. This strain produced 164 g/L xylitol from detoxified corncob hydrolysates during a fed-batch fermentation in a 15-L bioreactor, which was 14.7% higher than the xylitol produced by the starting strain, IS5-d (143 g/L), and the xylitol productivity was 3.04 g/L/h. These results represent the highest xylitol concentration and productivity reported to date for bacteria and hemicellulosic sugars. Additionally, strain IS5-dG, which differs from IS5-dI at CRP amino acid residue 127 (I127G), was tolerant to the toxins in corncob hydrolysates. In a fed-batch fermentation experiment involving a 15-L bioreactor, IS5-dG produced 137 g/L xylitol from non-detoxified corncob hydrolysates, with a productivity of 1.76 g/L/h. On the basis of these results, we believe that IS5-dI and IS5-dG may be useful host strains for the industrial-scale production of xylitol from detoxified or non-detoxified corncob hydrolysates.
Collapse
|
23
|
Zhang D, Chang Z, Li N, Lei M, Wang Z, Niu H, Gao N, Liu D, Chen Y. pH-Neutralization, Redox-Balanced Process with Coupled Formate Dehydrogenase and Glucose Dehydrogenase Supports Efficient Xylitol Production in Pure Water. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:235-241. [PMID: 31822063 DOI: 10.1021/acs.jafc.9b05626] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Enzymatic production of xylitol is a promising alternative to the chemical hydrogenation process. However, it encounters problems that are largely due to protein susceptibility to environmental factors. In this study, to develop a robust, practical enzymatic process for xylitol production, a coupled enzyme system consisting of formate dehydrogenase (FDH), glucose dehydrogenase (GDH), and xylose reductase (XR) was constructed, wherein the alkaline product produced by FDH and the acidic product produced by GDH could neutralize each other during cofactor regeneration. After optimization of conditions, a pH-neutralization, redox-balanced process was developed that could be carried out in pure water requiring no pH regulation. As a result, a xylitol production of 273.6 g/L that is much higher than those yet reported was obtained from 2 M xylose in 24 h, with a relatively high productivity of 11.4 g/(L h). The strategy demonstrated here can be adapted for the production of other NADH-consuming products.
Collapse
|
24
|
Prasad RK, Chatterjee S, Mazumder PB, Gupta SK, Sharma S, Vairale MG, Datta S, Dwivedi SK, Gupta DK. Bioethanol production from waste lignocelluloses: A review on microbial degradation potential. CHEMOSPHERE 2019; 231:588-606. [PMID: 31154237 DOI: 10.1016/j.chemosphere.2019.05.142] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 04/02/2019] [Accepted: 05/17/2019] [Indexed: 05/15/2023]
Abstract
Tremendous explosion of population has led to about 200% increment of total energy consumptions in last twenty-five years. Apart from conventional fossil fuel as limited energy source, alternative non-conventional sources are being explored worldwide to cater the energy requirement. Lignocellulosic biomass conversion for biofuel production is an important alternative energy source due to its abundance in nature and creating less harmful impacts on the environment in comparison to the coal or petroleum-based sources. However, lignocellulose biopolymer, the building block of plants, is a recalcitrant substance and difficult to break into desirable products. Commonly used chemical and physical methods for pretreating the substrate are having several limitations. Whereas, utilizing microbial potential to hydrolyse the biomass is an interesting area of research. Because of the complexity of substrate, several enzymes are required that can act synergistically to hydrolyse the biopolymer producing components like bioethanol or other energy substances. Exploring a range of microorganisms, like bacteria, fungi, yeast etc. that utilizes lignocelluloses for their energy through enzymatic breaking down the biomass, is one of the options. Scientists are working upon designing organisms through genetic engineering tools to integrate desired enzymes into a single organism (like bacterial cell). Studies on designer cellulosomes and bacteria consortia development relating consolidated bioprocessing are exciting to overcome the issue of appropriate lignocellulose digestions. This review encompasses up to date information on recent developments for effective microbial degradation processes of lignocelluloses for improved utilization to produce biofuel (bioethanol in particular) from the most plentiful substances of our planet.
Collapse
Affiliation(s)
- Rajesh Kumar Prasad
- Defence Research Laboratory, DRDO, Tezpur, 784001, Assam, India; Assam University, Silchar, 788011, Assam, India
| | | | | | | | - Sonika Sharma
- Defence Research Laboratory, DRDO, Tezpur, 784001, Assam, India
| | | | | | | | - Dharmendra Kumar Gupta
- Gottfried Wilhelm Leibniz Universität Hannover, Institut für Radioökologie und Strahlenschutz (IRS), HerrenhäuserStr. 2, 30419, Hannover, Germany
| |
Collapse
|
25
|
Yuan X, Wang J, Lin J, Yang L, Wu M. Efficient production of xylitol by the integration of multiple copies of xylose reductase gene and the deletion of Embden-Meyerhof-Parnas pathway-associated genes to enhance NADPH regeneration in Escherichia coli. J Ind Microbiol Biotechnol 2019; 46:1061-1069. [PMID: 31025135 DOI: 10.1007/s10295-019-02169-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 03/23/2019] [Indexed: 01/24/2023]
Abstract
Cofactor supply is a rate-limiting step in the bioconversion of xylose to xylitol. Strain WZ04 was first constructed by a novel simultaneous deletion-insertion strategy, replacing ptsG, xylAB and ptsF in wild-type Escherichia coli W3110 with three mutated xylose reductase genes (xr) from Neurospora crassa. Then, the pfkA, pfkB, pgi and/or sthA genes were deleted and replaced by xr to investigate the influence of carbon flux toward the pentose phosphate pathway and/or transhydrogenase activity on NADPH generation. The deletion of pfkA/pfkB significantly improved NADPH supply, but minimally influenced cell growth. The effects of insertion position and copy number of xr were examined by a quantitative real-time PCR and a shake-flask fermentation experiment. In a fed-batch fermentation experiment with a 15-L bioreactor, strain WZ51 produced 131.6 g L-1 xylitol from hemicellulosic hydrolysate (xylitol productivity: 2.09 g L-1 h-1). This study provided a potential approach for industrial-scale production of xylitol from hemicellulosic hydrolysate.
Collapse
Affiliation(s)
- Xinsong Yuan
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, People's Republic of China
| | - Jiping Wang
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, People's Republic of China
| | - Jianping Lin
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, People's Republic of China
| | - Lirong Yang
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, People's Republic of China
| | - Mianbin Wu
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, People's Republic of China.
| |
Collapse
|
26
|
Shah SSM, Luthfi AAI, Low KO, Harun S, Manaf SFA, Illias RM, Jahim JM. Preparation of kenaf stem hemicellulosic hydrolysate and its fermentability in microbial production of xylitol by Escherichia coli BL21. Sci Rep 2019; 9:4080. [PMID: 30858467 PMCID: PMC6411968 DOI: 10.1038/s41598-019-40807-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 02/19/2019] [Indexed: 12/20/2022] Open
Abstract
Kenaf (Hibiscus cannabinus L.), a potential fibre crop with a desirably high growth rate, could serve as a sustainable feedstock in the production of xylitol. In this work, the extraction of soluble products of kenaf through dilute nitric-acid hydrolysis was elucidated with respect to three parameters, namely temperature, residence time, and acid concentration. The study will assist in evaluating the performance in terms of xylose recovery. The result point out that the maximum xylose yield of 30.7 g per 100 g of dry kenaf was attained from 2% (v/v) HNO3 at 130 °C for 60 min. The detoxified hydrolysate was incorporated as the primary carbon source for subsequent fermentation by recombinant Escherichia coli and the performance of strain on five different semi-synthetic media on xylitol production were evaluated herein. Among these media, batch cultivation in a basal salt medium (BSM) afforded the highest xylitol yield of 0.35 g/g based on xylose consumption, which corresponded to 92.8% substrate utilization after 38 h. Subsequently, fermentation by E. coli in the xylose-based kenaf hydrolysate supplemented with BSM resulting in 6.8 g/L xylitol which corresponding to xylitol yield of 0.38 g/g. These findings suggested that the use of kenaf as the fermentation feedstock could be advantageous for the development of sustainable xylitol production.
Collapse
Affiliation(s)
- Siti Syazwani Mohd Shah
- Research Centre of Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor Darul Ehsan, Malaysia
| | - Abdullah Amru Indera Luthfi
- Research Centre of Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor Darul Ehsan, Malaysia
| | - Kheng Oon Low
- Malaysia Genome Institute (MGI), National Insitutes of Biotechnology Malaysia, Jalan Bangi Lama, Kajang, Malaysia
| | - Shuhaida Harun
- Chemical Engineering Programme, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor Darul Ehsan, Malaysia.,Research Centre of Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor Darul Ehsan, Malaysia
| | - Shareena Fairuz Abdul Manaf
- Chemical Engineering Programme, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor Darul Ehsan, Malaysia.,Research Centre of Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor Darul Ehsan, Malaysia.,Faculty of Chemical Engineering, Universiti Teknologi MARA, 40450, Shah Alam, Selangor Darul Ehsan, Malaysia
| | - Rosli Md Illias
- Malaysia Genome Institute (MGI), National Insitutes of Biotechnology Malaysia, Jalan Bangi Lama, Kajang, Malaysia
| | - Jamaliah Md Jahim
- Chemical Engineering Programme, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor Darul Ehsan, Malaysia. .,Research Centre of Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor Darul Ehsan, Malaysia.
| |
Collapse
|
27
|
Chang Z, Liu D, Yang Z, Wu J, Zhuang W, Niu H, Ying H. Efficient Xylitol Production from Cornstalk Hydrolysate Using Engineered Escherichia coli Whole Cells. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:13209-13216. [PMID: 30465421 DOI: 10.1021/acs.jafc.8b04666] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Economic transformation of lignocellulose hydrolysate into valued-added products is of particular importance for energy and environmental issues. In this study, xylose reductase and glucose dehydrogenase were cloned into plasmid pETDuet-1 and then simultaneously expressed in Escherichia coli BL21(DE3), which was used as whole-cell catalyst for the first time to convert xylose into xylitol coupled with gluconate production. When tested with reconstituted xylose and glucose solution, 0.1 g/mL cells could convert 1 M xylose and 1 M glucose completely and produced 145.81 g/L xylitol with a yield of 0.97 (g/g) and 184.85 g/L gluconic acid with a yield of 1.03 (g/g) in 24 h. Subsequently, the engineered cells were applied in real cornstalk hydrolysate, which generated 30.88 g/L xylitol and 50.89 g/L gluconic acid. The cells were used without penetration treatment, and CaCO3 was used to effectively regulate the pH during the production, which further saved costs.
Collapse
Affiliation(s)
- Ziyue Chang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering , Nanjing Tech University , No. 30, Puzhu South Road , Nanjing 211816 , China
| | - Dong Liu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering , Nanjing Tech University , No. 30, Puzhu South Road , Nanjing 211816 , China
| | - Zhengjiao Yang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering , Nanjing Tech University , No. 30, Puzhu South Road , Nanjing 211816 , China
| | - Jinglan Wu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering , Nanjing Tech University , No. 30, Puzhu South Road , Nanjing 211816 , China
| | - Wei Zhuang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering , Nanjing Tech University , No. 30, Puzhu South Road , Nanjing 211816 , China
| | - Huanqing Niu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering , Nanjing Tech University , No. 30, Puzhu South Road , Nanjing 211816 , China
| | - Hanjie Ying
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering , Nanjing Tech University , No. 30, Puzhu South Road , Nanjing 211816 , China
| |
Collapse
|
28
|
Ni W, Liu H, Wang P, Wang L, Sun X, Wang H, Zhao G, Zheng Z. Evaluation of multiple fused partners on enhancing soluble level of prenyltransferase NovQ in Escherichia coli. Bioprocess Biosyst Eng 2018; 42:465-474. [DOI: 10.1007/s00449-018-2050-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Accepted: 11/23/2018] [Indexed: 01/18/2023]
|
29
|
Efficient Biosynthesis of Xylitol from Xylose by Coexpression of Xylose Reductase and Glucose Dehydrogenase in Escherichia coli. Appl Biochem Biotechnol 2018; 187:1143-1157. [DOI: 10.1007/s12010-018-2878-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 08/28/2018] [Indexed: 01/02/2023]
|
30
|
An Automated Pipeline for Engineering Many-Enzyme Pathways: Computational Sequence Design, Pathway Expression-Flux Mapping, and Scalable Pathway Optimization. Methods Mol Biol 2018; 1671:39-61. [PMID: 29170952 DOI: 10.1007/978-1-4939-7295-1_4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Engineering many-enzyme metabolic pathways suffers from the design curse of dimensionality. There are an astronomical number of synonymous DNA sequence choices, though relatively few will express an evolutionary robust, maximally productive pathway without metabolic bottlenecks. To solve this challenge, we have developed an integrated, automated computational-experimental pipeline that identifies a pathway's optimal DNA sequence without high-throughput screening or many cycles of design-build-test. The first step applies our Operon Calculator algorithm to design a host-specific evolutionary robust bacterial operon sequence with maximally tunable enzyme expression levels. The second step applies our RBS Library Calculator algorithm to systematically vary enzyme expression levels with the smallest-sized library. After characterizing a small number of constructed pathway variants, measurements are supplied to our Pathway Map Calculator algorithm, which then parameterizes a kinetic metabolic model that ultimately predicts the pathway's optimal enzyme expression levels and DNA sequences. Altogether, our algorithms provide the ability to efficiently map the pathway's sequence-expression-activity space and predict DNA sequences with desired metabolic fluxes. Here, we provide a step-by-step guide to applying the Pathway Optimization Pipeline on a desired multi-enzyme pathway in a bacterial host.
Collapse
|
31
|
Han Q, Eiteman MA. Coupling xylitol dehydrogenase with NADH oxidase improves l-xylulose production in Escherichia coli culture. Enzyme Microb Technol 2017; 106:106-113. [PMID: 28859803 DOI: 10.1016/j.enzmictec.2017.07.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 07/06/2017] [Accepted: 07/21/2017] [Indexed: 11/30/2022]
Abstract
Escherichia coli expressing NAD-dependent xylitol-4-dehydrogenase (XDH) from Pantoea ananatis and growing on glucose or glycerol converts xylitol to the rare sugar l-xylulose. Although blocking potential l-xylulose consumption (l-xylulosekinase, lyxK) or co-expression of the glycerol facilitator (glpF) did not significantly affect l-xylulose formation, co-expressing XDH with water-forming NADH oxidase (NOX) from Streptococcus pneumoniae increased l-xylulose formation in shake flasks when glycerol was the carbon source. Controlled batch processes at the 1L scale demonstrated that the final equilibrium l-xylulose/xylitol ratio was correlated to the intracellular NAD+/NADH ratio, with 69% conversion of xylitol to l-xylulose and a yield of 0.88g l-xylulose/g xylitol consumed attained for MG1655/pZE12-xdh/pCS27-nox growing on glycerol. NADH oxidase was less effective at improving l-xylulose formation in the bioreactor than in shake flasks, likely as a result of an intrinsic maximum NAD+/NADH and l-xylulose/xylitol equilibrium ratio being attained. Intermittently feeding carbon source was ineffective at increasing the final l-xylulose concentration because introduction of carbon source was accompanied by a reduction in NAD+/NADH ratio. A batch process using 12g/L glycerol and 22g/L xylitol generated over 14g/L l-xylulose after 80h, corresponding to 65% conversion and a yield of 0.89g l-xylulose/g xylitol consumed.
Collapse
Affiliation(s)
- Qi Han
- School of Chemical, Materials and Biomedical Engineering University of Georgia, Athens, GA, 30602, USA
| | - Mark A Eiteman
- School of Chemical, Materials and Biomedical Engineering University of Georgia, Athens, GA, 30602, USA.
| |
Collapse
|
32
|
Metabolic engineering of Escherichia coli to produce gamma-aminobutyric acid using xylose. Appl Microbiol Biotechnol 2017; 101:3587-3603. [DOI: 10.1007/s00253-017-8162-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 01/06/2017] [Accepted: 01/27/2017] [Indexed: 02/07/2023]
|
33
|
Enhanced Production of Xylitol from Poplar Wood Hydrolysates Through a Sustainable Process Using Immobilized New Strain Candida tropicalis UFMG BX 12-a. Appl Biochem Biotechnol 2017; 182:1053-1064. [PMID: 28054259 DOI: 10.1007/s12010-016-2381-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 12/21/2016] [Indexed: 10/20/2022]
Abstract
A new strain, Candida tropicalis UFMG BX 12-a, was found to produce higher yields of xylitol on poplar wood hemicellulose hydrolysate. The hemicellulose hydrolysate liquor was detoxified using a novel method we developed, involving vacuum evaporation and solvent separation of inhibitors which made the hydrolysate free of toxins while retaining high concentrations of fermentable sugars. The effect of the detoxification method on the fermentation was also reported and compared to well-known methods reported in literature. In this study, the new strain C. tropicalis UFMG BX 12-a was used on the detoxified hydrolysate to produce xylitol. It was also compared to Candida guilliermondii FTI 20037, which has been reported to be one of the best strains for fermentative production of xylitol. To further improve the efficiency of the fermentation process, these strains were immobilized in calcium alginate beads. The yield (0.92 g g-1) and productivity (0.88 g L-1 h-1) obtained by fermenting the wood hydrolysate detoxified by our new detoxification technique using an immobilized new Candida strain were found to be higher than the values reported in literature.
Collapse
|
34
|
Zhang Z, Su B, Wu M, Lin J, Yang L. Strategies for eliminating l-arabinitol in the bioconversion of xylitol. Process Biochem 2016. [DOI: 10.1016/j.procbio.2016.08.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
35
|
Metabolic pathway optimization for biosynthesis of 1,2,4-butanetriol from xylose by engineered Escherichia coli. Enzyme Microb Technol 2016; 93-94:51-58. [DOI: 10.1016/j.enzmictec.2016.07.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 07/16/2016] [Accepted: 07/18/2016] [Indexed: 12/22/2022]
|
36
|
Venkateswar Rao L, Goli JK, Gentela J, Koti S. Bioconversion of lignocellulosic biomass to xylitol: An overview. BIORESOURCE TECHNOLOGY 2016; 213:299-310. [PMID: 27142629 DOI: 10.1016/j.biortech.2016.04.092] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 04/16/2016] [Accepted: 04/19/2016] [Indexed: 06/05/2023]
Abstract
Lignocellulosic wastes include agricultural and forest residues which are most promising alternative energy sources and serve as potential low cost raw materials that can be exploited to produce xylitol. The strong physical and chemical construction of lignocelluloses is a major constraint for the recovery of xylose. The large scale production of xylitol is attained by nickel catalyzed chemical process that is based on xylose hydrogenation, that requires purified xylose as raw substrate and the process requires high temperature and pressure that remains to be cost intensive and energy consuming. Therefore, there is a necessity to develop an integrated process for biotechnological conversion of lignocelluloses to xylitol and make the process economical. The present review confers about the pretreatment strategies that facilitate cellulose and hemicellulose acquiescent for hydrolysis. There is also an emphasis on various detoxification and fermentation methodologies including genetic engineering strategies for the efficient conversion of xylose to xylitol.
Collapse
Affiliation(s)
- Linga Venkateswar Rao
- Dept. of Microbiology, Osmania University, Hyderabad, Telangana State 500 007, India.
| | - Jyosthna Khanna Goli
- Dept. of Microbiology, Osmania University, Hyderabad, Telangana State 500 007, India
| | - Jahnavi Gentela
- Dept. of Microbiology, Osmania University, Hyderabad, Telangana State 500 007, India
| | - Sravanthi Koti
- Dept. of Microbiology, Osmania University, Hyderabad, Telangana State 500 007, India
| |
Collapse
|
37
|
Su B, Zhang Z, Wu M, Lin J, Yang L. Construction of plasmid-free Escherichia coli for the production of arabitol-free xylitol from corncob hemicellulosic hydrolysate. Sci Rep 2016; 6:26567. [PMID: 27225023 PMCID: PMC4880924 DOI: 10.1038/srep26567] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 05/04/2016] [Indexed: 11/22/2022] Open
Abstract
High costs and low production efficiency are a serious constraint to bio-based xylitol production. For industrial-scale production of xylitol, a plasmid-free Escherichia coli for arabitol-free xylitol production from corncob hemicellulosic hydrolysate has been constructed. Instead of being plasmid and inducer dependent, this strain relied on multiple-copy integration of xylose reductase (XR) genes into the chromosome, where their expression was controlled by the constitutive promoter P43. In addition, to minimize the flux from L-arabinose to arabitol, two strategies including low XR total activity and high selectivity of XR has been adopted. Arabitol was significantly decreased using plasmid-free strain which had lower XR total activity and an eight point-mutations of XR with a 27-fold lower enzyme activity toward L-arabinose was achieved. The plasmid-free strain in conjunction with this mutant XR can completely eliminate arabitol formation in xylitol production. In fed-batch fermentation, this plasmid-free strain produced 143.8 g L(-1) xylitol at 1.84 g L(-1) h(-1) from corncob hemicellulosic hydrolysate. From these results, we conclude that this route by plasmid-free E. coli has potential to become a commercially viable process for xylitol production.
Collapse
Affiliation(s)
- Buli Su
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Zhe Zhang
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Mianbin Wu
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Jianping Lin
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Lirong Yang
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| |
Collapse
|
38
|
Qi XH, Zhu JF, Yun JH, Lin J, Qi YL, Guo Q, Xu H. Enhanced xylitol production: Expression of xylitol dehydrogenase from Gluconobacter oxydans and mixed culture of resting cell. J Biosci Bioeng 2016; 122:257-62. [PMID: 26975753 DOI: 10.1016/j.jbiosc.2016.02.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 02/03/2016] [Accepted: 02/15/2016] [Indexed: 12/24/2022]
Abstract
Xylitol has numerous applications in food and pharmaceutical industry, and it can be biosynthesized by microorganisms. In the present study, xdh gene, encoding xylitol dehydrogenase (XDH), was cloned from the genome of Gluconobacter oxydans CGMCC 1.49 and overexpressed in Escherichia coli BL21. Sequence analysis revealed that XDH has a TGXXGXXG NAD(H)-binding motif and a YXXXK active site motif, and belongs to the short-chain dehydrogenase/reductase family. And then, the enzymatic properties and kinetic parameter of purified recombinant XDH were investigated. Subsequently, transformations of xylitol from d-xylulose and d-arabitol, respectively, were studied through mixed culture of resting cells of G. oxydans wild-type strain and recombinant strain BL21-xdh. We obtained 28.80 g/L xylitol by mixed culture from 30 g/L d-xylulose in 28 h. The production was increased by more than three times as compared with that of wild-type strain. Furthermore, 25.10 g/L xylitol was produced by the mixed culture from 30 g/L d-arabitol in 30 h with a yield of 0.837 g/g, and the max volumetric productivity of 0.990 g/L h was obtained at 22 h. These contrast to the fact that wild-type strain G. oxydans only produced 8.10 g/L xylitol in 30 h with a yield of 0.270 g/g. To our knowledge, these values are the highest among the reported yields and productivity efficiencies of xylitol from d-arabitol with engineering strains.
Collapse
Affiliation(s)
- Xiang-Hui Qi
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China.
| | - Jing-Fei Zhu
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Jun-Hua Yun
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Jing Lin
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Yi-Lin Qi
- College of Science and Technology, Agricultural University of Hebei, Cangzhou 061100, China
| | - Qi Guo
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Hong Xu
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing 210009, China
| |
Collapse
|
39
|
Park YC, Oh EJ, Jo JH, Jin YS, Seo JH. Recent advances in biological production of sugar alcohols. Curr Opin Biotechnol 2016; 37:105-113. [DOI: 10.1016/j.copbio.2015.11.006] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 11/04/2015] [Accepted: 11/09/2015] [Indexed: 11/16/2022]
|
40
|
Hollinshead WD, Rodriguez S, Martin HG, Wang G, Baidoo EEK, Sale KL, Keasling JD, Mukhopadhyay A, Tang YJ. Examining Escherichia coli glycolytic pathways, catabolite repression, and metabolite channeling using Δ pfk mutants. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:212. [PMID: 27766116 PMCID: PMC5057261 DOI: 10.1186/s13068-016-0630-y] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 09/28/2016] [Indexed: 05/09/2023]
Abstract
BACKGROUND Glycolysis breakdowns glucose into essential building blocks and ATP/NAD(P)H for the cell, occupying a central role in its growth and bio-production. Among glycolytic pathways, the Entner Doudoroff pathway (EDP) is a more thermodynamically favorable pathway with fewer enzymatic steps than either the Embden-Meyerhof-Parnas pathway (EMPP) or the oxidative pentose phosphate pathway (OPPP). However, Escherichia coli do not use their native EDP for glucose metabolism. RESULTS Overexpression of edd and eda in E. coli to enhance EDP activity resulted in only a small shift in the flux directed through the EDP (~20 % of glycolysis flux). Disrupting the EMPP by phosphofructokinase I (pfkA) knockout increased flux through OPPP (~60 % of glycolysis flux) and the native EDP (~14 % of glycolysis flux), while overexpressing edd and eda in this ΔpfkA mutant directed ~70 % of glycolytic flux through the EDP. The downregulation of EMPP via the pfkA deletion significantly decreased the growth rate, while EDP overexpression in the ΔpfkA mutant failed to improve its growth rates due to metabolic burden. However, the reorganization of E. coli glycolytic strategies did reduce glucose catabolite repression. The ΔpfkA mutant in glucose medium was able to cometabolize acetate via the citric acid cycle and gluconeogenesis, while EDP overexpression in the ΔpfkA mutant repressed acetate flux toward gluconeogenesis. Moreover, 13C-pulse experiments in the ΔpfkA mutants showed unsequential labeling dynamics in glycolysis intermediates, possibly suggesting metabolite channeling (metabolites in glycolysis are pass from enzyme to enzyme without fully equilibrating within the cytosol medium). CONCLUSIONS We engineered E. coli to redistribute its native glycolytic flux. The replacement of EMPP by EDP did not improve E. coli glucose utilization or biomass growth, but alleviated catabolite repression. More importantly, our results supported the hypothesis of channeling in the glycolytic pathways, a potentially overlooked mechanism for regulating glucose catabolism and coutilization of other substrates. The presence of channeling in native pathways, if proven true, would affect synthetic biology applications and metabolic modeling.
Collapse
Affiliation(s)
- Whitney D. Hollinshead
- Department of Energy, Environmental and Chemical Engineering, Washington University, St. Louis, MO USA
| | - Sarah Rodriguez
- Sandia National Laboratory, Livermore, CA USA
- Joint BioEnergy Institute, Emeryville, CA USA
| | - Hector Garcia Martin
- Joint BioEnergy Institute, Emeryville, CA USA
- Lawrence Berkeley National Laboratory, Biological Systems and Engineering Division, Berkeley, CA USA
| | - George Wang
- Joint BioEnergy Institute, Emeryville, CA USA
- Lawrence Berkeley National Laboratory, Biological Systems and Engineering Division, Berkeley, CA USA
| | - Edward E. K. Baidoo
- Joint BioEnergy Institute, Emeryville, CA USA
- Lawrence Berkeley National Laboratory, Biological Systems and Engineering Division, Berkeley, CA USA
| | - Kenneth L. Sale
- Joint BioEnergy Institute, Emeryville, CA USA
- Lawrence Berkeley National Laboratory, Biological Systems and Engineering Division, Berkeley, CA USA
| | - Jay D. Keasling
- Joint BioEnergy Institute, Emeryville, CA USA
- Lawrence Berkeley National Laboratory, Biological Systems and Engineering Division, Berkeley, CA USA
- California Institute of Quantitative Biosciences (QB3), University of California, Berkeley, CA USA
- Department of Bioengineering, University of California, Berkeley, CA USA
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA USA
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kogle Allé, DK2970 Hørsholm, Denmark
| | - Aindrila Mukhopadhyay
- Joint BioEnergy Institute, Emeryville, CA USA
- Lawrence Berkeley National Laboratory, Biological Systems and Engineering Division, Berkeley, CA USA
| | - Yinjie J. Tang
- Department of Energy, Environmental and Chemical Engineering, Washington University, St. Louis, MO USA
| |
Collapse
|