1
|
Peng Y, Xu P, Tao F. Production of N-acetylglucosamine with Vibrio alginolyticus FA2, an emerging platform for economical unsterile open fermentation. Synth Syst Biotechnol 2023; 8:546-554. [PMID: 37637200 PMCID: PMC10457514 DOI: 10.1016/j.synbio.2023.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/01/2023] [Accepted: 08/09/2023] [Indexed: 08/29/2023] Open
Abstract
Members of the Vibrionaceae family are predominantly fast-growing and halophilic microorganisms that have captured the attention of researchers owing to their potential applications in rapid biotechnology. Among them, Vibrio alginolyticus FA2 is a particularly noteworthy halophilic bacterium that exhibits superior growth capability. It has the potential to serve as a biotechnological platform for sustainable and eco-friendly open fermentation with seawater. To evaluate this hypothesis, we integrated the N-acetylglucosamine (GlcNAc) pathway into V. alginolyticus FA2. Seven nag genes were knocked out to obstruct the utilization of GlcNAc, and then 16 exogenous gna1s co-expressing with EcglmS were introduced to strengthen the flux of GlcNAc pathway, respectively. To further enhance GlcNAc production, we fine-tuned promoter strength of the two genes and inactivated two genes alsS and alsD to prevent the production of acetoin. Furthermore, unsterile open fermentation was carried out using simulated seawater and a chemically defined medium, resulting in the production of 9.2 g/L GlcNAc in 14 h. This is the first report for de-novo synthesizing GlcNAc with a Vibrio strain, facilitated by an unsterile open fermentation process employing seawater as a substitute for fresh water. This development establishes a basis for production of diverse valuable chemicals using Vibrio strains and provides insights into biomanufacture.
Collapse
Affiliation(s)
- Yuan Peng
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Ping Xu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Fei Tao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| |
Collapse
|
2
|
High production of acetoin from glycerol by Bacillus subtilis 35. Appl Microbiol Biotechnol 2022; 107:175-185. [DOI: 10.1007/s00253-022-12301-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 11/16/2022] [Accepted: 11/18/2022] [Indexed: 12/05/2022]
|
3
|
Wang G, Wang M, Liu L, Hui X, Wang B, Ma K, Yang X. Improvement of the catalytic performance of glycerol kinase from Bacillus subtilis by chromosomal site-directed mutagenesis. Biotechnol Lett 2022; 44:1051-1061. [PMID: 35922648 DOI: 10.1007/s10529-022-03281-8] [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: 01/29/2022] [Accepted: 07/11/2022] [Indexed: 11/24/2022]
Abstract
Glycerol kinase is the key enzyme in glycerol metabolism, and its catalytic efficiency has an important effect on glycerol utilization. Based on an analysis of the glycerol utilization pathway and regulation mechanism in B. subtilis, we conducted site-directed mutagenesis of the key glycerol kinase gene (glpK) on the chromosome to improve the glycerol utilization efficiency of Bacillus subtilis. Recombinant wild-type Bacillus subtilis glycerol kinase (BsuGlpKWT) and two mutants (BsuGlpKM270I and BsuGlpKS71V) were successfully overexpressed in Escherichia coli BL21(DE3) and purified by Ni-IDA metal chelate chromatography. The specific activity of the BsuGlpKM270I mutant (62.6 U/mg) was significantly higher (296.2%) than that of wild-type BsuGlpKWT (15.8 U/mg). By contrast, the mutant BsuGlpKS71V (4.89 U/mg) exhibited lower (69.1%) activity than BsuGlpKWT, which suggested that variant S71V exhibited reduced catalytic efficiency for the substrate. Furthermore, the mutant strain B. subtilis M270I was constructed using a markerless delivery system, and exhibited a higher specific growth rate (improved by 11.3%, from 0.453 ± 0.012 to 0.511 ± 0.017 h-1) and higher maximal biomass (cell dry weight increased by 16%, from 0.577 ± 0.033 to 0.721 ± 0.015 g/L) than the parental strain with a shortened lag phase (2 ~ 4 h shorter) in M9 minimal medium with glycerol. These results indicate that the mutated glpK resulted in improved glycerol utilization, which has broad application prospects.
Collapse
Affiliation(s)
- Guanglu Wang
- Laboratory of Biotransformation and Biocatalysis, School of Food and Biological Engineering, Zhengzhou University of Light Industry, Zhengzhou, Dongfeng Road 5, Henan, 450000, People's Republic of China.,School of Food and Bioengineering/Collaborative Innovation Center for Food Production and Safety, Zhengzhou University of Light Industry, Dongfeng Road 5, Zhengzhou, Henan, 450001, People's Republic of China
| | - Mengyuan Wang
- Laboratory of Biotransformation and Biocatalysis, School of Food and Biological Engineering, Zhengzhou University of Light Industry, Zhengzhou, Dongfeng Road 5, Henan, 450000, People's Republic of China.,School of Food and Bioengineering/Collaborative Innovation Center for Food Production and Safety, Zhengzhou University of Light Industry, Dongfeng Road 5, Zhengzhou, Henan, 450001, People's Republic of China
| | - Lanxi Liu
- Laboratory of Biotransformation and Biocatalysis, School of Food and Biological Engineering, Zhengzhou University of Light Industry, Zhengzhou, Dongfeng Road 5, Henan, 450000, People's Republic of China.,School of Food and Bioengineering/Collaborative Innovation Center for Food Production and Safety, Zhengzhou University of Light Industry, Dongfeng Road 5, Zhengzhou, Henan, 450001, People's Republic of China
| | - Xiaohan Hui
- Laboratory of Biotransformation and Biocatalysis, School of Food and Biological Engineering, Zhengzhou University of Light Industry, Zhengzhou, Dongfeng Road 5, Henan, 450000, People's Republic of China.,School of Food and Bioengineering/Collaborative Innovation Center for Food Production and Safety, Zhengzhou University of Light Industry, Dongfeng Road 5, Zhengzhou, Henan, 450001, People's Republic of China
| | - Bingyang Wang
- Laboratory of Biotransformation and Biocatalysis, School of Food and Biological Engineering, Zhengzhou University of Light Industry, Zhengzhou, Dongfeng Road 5, Henan, 450000, People's Republic of China.,School of Food and Bioengineering/Collaborative Innovation Center for Food Production and Safety, Zhengzhou University of Light Industry, Dongfeng Road 5, Zhengzhou, Henan, 450001, People's Republic of China
| | - Ke Ma
- Laboratory of Biotransformation and Biocatalysis, School of Food and Biological Engineering, Zhengzhou University of Light Industry, Zhengzhou, Dongfeng Road 5, Henan, 450000, People's Republic of China.,School of Food and Bioengineering/Collaborative Innovation Center for Food Production and Safety, Zhengzhou University of Light Industry, Dongfeng Road 5, Zhengzhou, Henan, 450001, People's Republic of China
| | - Xuepeng Yang
- Laboratory of Biotransformation and Biocatalysis, School of Food and Biological Engineering, Zhengzhou University of Light Industry, Zhengzhou, Dongfeng Road 5, Henan, 450000, People's Republic of China. .,School of Food and Bioengineering/Collaborative Innovation Center for Food Production and Safety, Zhengzhou University of Light Industry, Dongfeng Road 5, Zhengzhou, Henan, 450001, People's Republic of China.
| |
Collapse
|
4
|
Liu J, Liu M, Shi T, Sun G, Gao N, Zhao X, Guo X, Ni X, Yuan Q, Feng J, Liu Z, Guo Y, Chen J, Wang Y, Zheng P, Sun J. CRISPR-assisted rational flux-tuning and arrayed CRISPRi screening of an L-proline exporter for L-proline hyperproduction. Nat Commun 2022; 13:891. [PMID: 35173152 PMCID: PMC8850433 DOI: 10.1038/s41467-022-28501-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 01/24/2022] [Indexed: 02/07/2023] Open
Abstract
Development of hyperproducing strains is important for biomanufacturing of biochemicals and biofuels but requires extensive efforts to engineer cellular metabolism and discover functional components. Herein, we optimize and use the CRISPR-assisted editing and CRISPRi screening methods to convert a wild-type Corynebacterium glutamicum to a hyperproducer of L-proline, an amino acid with medicine, feed, and food applications. To facilitate L-proline production, feedback-deregulated variants of key biosynthetic enzyme γ-glutamyl kinase are screened using CRISPR-assisted single-stranded DNA recombineering. To increase the carbon flux towards L-proline biosynthesis, flux-control genes predicted by in silico analysis are fine-tuned using tailored promoter libraries. Finally, an arrayed CRISPRi library targeting all 397 transporters is constructed to discover an L-proline exporter Cgl2622. The final plasmid-, antibiotic-, and inducer-free strain produces L-proline at the level of 142.4 g/L, 2.90 g/L/h, and 0.31 g/g. The CRISPR-assisted strain development strategy can be used for engineering industrial-strength strains for efficient biomanufacturing.
Collapse
Affiliation(s)
- Jiao Liu
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Moshi Liu
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Tuo Shi
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Guannan Sun
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ning Gao
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaojia Zhao
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xuan Guo
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Xiaomeng Ni
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Qianqian Yuan
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Jinhui Feng
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Zhemin Liu
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Yanmei Guo
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Jiuzhou Chen
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Yu Wang
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China. .,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Ping Zheng
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China. .,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Jibin Sun
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| |
Collapse
|
5
|
Meng W, Ma C, Xu P, Gao C. Biotechnological production of chiral acetoin. Trends Biotechnol 2022; 40:958-973. [DOI: 10.1016/j.tibtech.2022.01.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 01/13/2022] [Accepted: 01/13/2022] [Indexed: 11/28/2022]
|
6
|
Tan C, Xu P, Tao F. Harnessing Interactional Sensory Genes for Rationally Reprogramming Chaotic Metabolism. RESEARCH 2022. [DOI: 10.34133/research.0017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Rationally controlling cellular metabolism is of great importance but challenging owing to its highly complex and chaotic nature. Natural existing sensory proteins like histidine kinases (HKs) are understood as “sensitive nodes” of biological networks that can trigger disruptive metabolic reprogramming (MRP) upon perceiving environmental fluctuation. Here, the “sensitive node” genes were adopted to devise a global MRP platform consisting of a CRISPR interference-mediated dual-gene combinational knockdown toolbox and survivorship-based metabolic interaction decoding algorithm. The platform allows users to decode the interfering effects of
n
×
n
gene pairs while only requiring the synthesis of
n
pairs of primers. A total of 35 HK genes and 24 glycine metabolic genes were selected as the targets to determine the effectiveness of our platform in a
Vibrio
sp. FA2. The platform was applied to decode the interfering impact of HKs on antibiotic resistance in strain FA2. A pattern of combined knockdown of HK genes (
sasA_8
and
04288
) was demonstrated to be capable of reducing antibiotic resistance of
Vibrio
by 108-fold. Patterns of combined knockdown of glycine pathway genes (e.g.,
gcvT
and
ltaE
) and several HK genes (e.g.,
cpxA
and
btsS
) were also revealed to increase glycine production. Our platform may enable an efficient and rational approach for global MRP based on the elucidation of high-order gene interactions. A web-based 1-stop service (
https://smrp.sjtu.edu.cn
) is also provided to simplify the implementation of this smart strategy in a broad range of cells.
Collapse
Affiliation(s)
- Chunlin Tan
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Ping Xu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Fei Tao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| |
Collapse
|
7
|
Cui Z, Wang Z, Zheng M, Chen T. Advances in biological production of acetoin: a comprehensive overview. Crit Rev Biotechnol 2021; 42:1135-1156. [PMID: 34806505 DOI: 10.1080/07388551.2021.1995319] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Acetoin, a high-value-added bio-based platform chemical, is widely used in foods, cosmetics, agriculture, and the chemical industry. It is an important precursor for the synthesis of: 2,3-butanediol, liquid hydrocarbon fuels and heterocyclic compounds. Since the fossil resources are becoming increasingly scarce, biological production of acetoin has received increasing attention as an alternative to chemical synthesis. Although there are excellent reviews on the: application, catabolism and fermentative production of acetoin, little attention has been paid to acetoin production via: electrode-assisted fermentation, whole-cell biocatalysis, and in vitro/cell-free biocatalysis. In this review, acetoin biosynthesis pathways and relevant key enzymes are firstly reviewed. In addition, various strategies for biological acetoin production are summarized including: cell-free biocatalysis, whole-cell biocatalysis, microbial fermentation, and electrode-assisted fermentation. The advantages and disadvantages of the different approaches are discussed and weighed, illustrating the increasing progress toward economical, green and efficient production of acetoin. Additionally, recent advances in acetoin extraction and recovery in downstream processing are also briefly reviewed. Moreover, the current issues and future prospects of diverse strategies for biological acetoin production are discussed, with the hope of realizing the promises of industrial acetoin biomanufacturing in the near future.
Collapse
Affiliation(s)
- Zhenzhen Cui
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, China
| | - Zhiwen Wang
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, China
| | - Meiyu Zheng
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, China
| | - Tao Chen
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, China
| |
Collapse
|
8
|
Maina S, Prabhu AA, Vivek N, Vlysidis A, Koutinas A, Kumar V. Prospects on bio-based 2,3-butanediol and acetoin production: Recent progress and advances. Biotechnol Adv 2021; 54:107783. [PMID: 34098005 DOI: 10.1016/j.biotechadv.2021.107783] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 05/27/2021] [Accepted: 06/02/2021] [Indexed: 11/19/2022]
Abstract
The bio-based platform chemicals 2,3-butanediol (BDO) and acetoin have various applications in chemical, cosmetics, food, agriculture, and pharmaceutical industries, whereas the derivatives of BDO could be used as fuel additives, polymer and synthetic rubber production. This review summarizes the novel technological developments in adapting genetic and metabolic engineering strategies for selection and construction of chassis strains for BDO and acetoin production. The valorization of renewable feedstocks and bioprocess development for the upstream and downstream stages of bio-based BDO and acetoin production are discussed. The techno-economic aspects evaluating the viability and industrial potential of bio-based BDO production are presented. The commercialization of bio-based BDO and acetoin production requires the utilization of crude renewable resources, the chassis strains with high fermentation production efficiencies and development of sustainable purification or conversion technologies.
Collapse
Affiliation(s)
- Sofia Maina
- Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos, 75, 11855 Athens, Greece
| | - Ashish A Prabhu
- Centre for Climate and Environmental Protection, School of Water, Energy and Environment, Cranfield University, Cranfield MK43 0AL, UK
| | - Narisetty Vivek
- Centre for Climate and Environmental Protection, School of Water, Energy and Environment, Cranfield University, Cranfield MK43 0AL, UK
| | - Anestis Vlysidis
- Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos, 75, 11855 Athens, Greece
| | - Apostolis Koutinas
- Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos, 75, 11855 Athens, Greece.
| | - Vinod Kumar
- Centre for Climate and Environmental Protection, School of Water, Energy and Environment, Cranfield University, Cranfield MK43 0AL, UK.
| |
Collapse
|
9
|
Switching metabolic flux by engineering tryptophan operon-assisted CRISPR interference system in Klebsiella pneumoniae. Metab Eng 2021; 65:30-41. [PMID: 33684594 DOI: 10.1016/j.ymben.2021.03.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 12/22/2020] [Accepted: 03/01/2021] [Indexed: 01/17/2023]
Abstract
One grand challenge for bioproduction of desired metabolites is how to coordinate cell growth and product synthesis. Here we report that a tryptophan operon-assisted CRISPR interference (CRISPRi) system can switch glycerol oxidation and reduction pathways in Klebsiella pneumoniae, whereby the oxidation pathway provides energy to sustain growth, and the reduction pathway generates 1,3-propanediol and 3-hydroxypropionic acid (3-HP), two economically important chemicals. Reverse transcription and quantitative PCR (RT-qPCR) showed that this CRISPRi-dependent switch affected the expression of glycerol metabolism-related genes and in turn improved 3-HP production. In shake-flask cultivation, the strain coexpressing dCas9-sgRNA and PuuC (an aldehyde dehydrogenase native to K. pneumoniae for 3-HP biosynthesis) produced 3.6 g/L 3-HP, which was 1.62 times that of the strain only overexpressing PuuC. In a 5 L bioreactor, this CRISPRi strain produced 58.9 g/L 3-HP. When circulation feeding was implemented to alleviate metabolic stress, biomass was substantially improved and 88.8 g/L 3-HP was produced. These results indicated that this CRISPRi-dependent switch can efficiently reconcile biomass formation and 3-HP biosynthesis. Furthermore, this is the first report of coupling CRISPRi system with trp operon, and this architecture holds huge potential in regulating gene expression and allocating metabolic flux.
Collapse
|
10
|
In-situ generation of large numbers of genetic combinations for metabolic reprogramming via CRISPR-guided base editing. Nat Commun 2021; 12:678. [PMID: 33514753 PMCID: PMC7846839 DOI: 10.1038/s41467-021-21003-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 01/07/2021] [Indexed: 11/09/2022] Open
Abstract
Reprogramming complex cellular metabolism requires simultaneous regulation of multigene expression. Ex-situ cloning-based methods are commonly used, but the target gene number and combinatorial library size are severely limited by cloning and transformation efficiencies. In-situ methods such as multiplex automated genome engineering (MAGE) depends on high-efficiency transformation and incorporation of heterologous DNA donors, which are limited to few microorganisms. Here, we describe a Base Editor-Targeted and Template-free Expression Regulation (BETTER) method for simultaneously diversifying multigene expression. BETTER repurposes CRISPR-guided base editors and in-situ generates large numbers of genetic combinations of diverse ribosome binding sites, 5’ untranslated regions, or promoters, without library construction, transformation, and incorporation of DNA donors. We apply BETTER to simultaneously regulate expression of up to ten genes in industrial and model microorganisms Corynebacterium glutamicum and Bacillus subtilis. Variants with improved xylose catabolism, glycerol catabolism, or lycopene biosynthesis are respectively obtained. This technology will be useful for large-scale fine-tuning of multigene expression in both genetically tractable and intractable microorganisms. To obtain optimal yield and productivity in bioproduction, expression of pathway genes must be appropriately coordinated. Here, the authors report repurposing of base editors for simultaneous regulation of multiple gene expression and demonstrate its application in industrially important and model microorganisms.
Collapse
|
11
|
Jing W, Liu J, Wu S, Chen Q, Li X, Liu Y. Development of a Method for Simultaneous Generation of Multiple Genetic Modification in Salmonella enterica Serovar Typhimurium. Front Genet 2020; 11:563491. [PMID: 33193646 PMCID: PMC7544003 DOI: 10.3389/fgene.2020.563491] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 08/19/2020] [Indexed: 01/29/2023] Open
Abstract
To comprehensively analyze bacterial gene function, it is important to simultaneously generate multiple genetic modifications within the target gene. However, current genetic engineering approaches, which mainly use suicide vector- or λ red homologous recombination-based systems, are tedious and technically difficult to perform. Here, we developed a flexible and easy method to simultaneously construct multiple modifications at the same locus on the Salmonella enterica serovar Typhimurium chromosome. The method combines an efficient seamless assembly system in vitro, red homologous recombination in vivo, and counterselection marker sacB. To test this method, with the seamless assembly system, various modification fragments for target genes cpxR, cpxA, and acrB were rapidly and efficiently constructed in vitro. sacBKan cassettes generated via polymerase chain reaction were inserted into the target loci in the genome of Salmonella Typhimurium strain CVCC541. The resulting pKD46-containing kanamycin-resistant recombinants were selected and used as intermediate strains. Multiple target gene modifications were then carried out simultaneously via allelic exchange using various homologous recombinogenic DNA fragments to replace the sacBKan cassettes in the chromosomes of the intermediate strains. Using this method, we successfully carried out site-directed mutagenesis, seamless deletion, and 3 × FLAG tagging of the target genes. This method can be used in any bacterial species that supports sacB gene activity and λ red-mediated recombination, allowing in-depth functional analysis of bacterial genes.
Collapse
Affiliation(s)
- Wenxian Jing
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Juan Liu
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Shanshan Wu
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Qiwei Chen
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Xuerui Li
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Yongsheng Liu
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| |
Collapse
|
12
|
Li X, Chu J, Jensen PR. The Expression of NOX From Synthetic Promoters Reveals an Important Role of the Redox Status in Regulating Secondary Metabolism of Saccharopolyspora erythraea. Front Bioeng Biotechnol 2020; 8:818. [PMID: 32766231 PMCID: PMC7379104 DOI: 10.3389/fbioe.2020.00818] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 06/26/2020] [Indexed: 12/17/2022] Open
Abstract
Redox cofactors play a pivotal role in primary cellular metabolism, whereas the clear link between redox status and secondary metabolism is still vague. In this study we investigated effects of redox perturbation on the production of erythromycin in Saccharopolyspora erythraea by expressing the water-forming NADH oxidase (NOX) from Streptococcus pneumonia at different levels with synthetic promoters. The expression of NOX reduced the intracellular [NADH]/[NAD+] ratio significantly in S. erythraea which resulted in an increased production of erythromycin by 19∼29% and this increment rose to 60% as more oxygen was supplied. In contrast, the lower redox ratio resulted in a decreased production of another secondary metabolite, the reddish pigment 7-O-rahmnosyl flaviolin. The metabolic shifts of secondary metabolism results in a higher NADH availability which compensates for its oxidization via NOX. The expression of the erythromycin biosynthesis gene cluster (BGC) in the NOX-expression strains was upregulated as the activity of diguanylate cyclase was inhibited moderately by NADH. This study also suggested that lower intracellular [NADH]/[NAD+] ratio benefits the biosynthesis of erythromycin by potentially affecting the biosynthesis of the secondary messenger, bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP), which may stimulate the positive regulation of erythromycin BGC via BldD. The present work provides a basis for future cofactor manipulation in S. erythraea to improve the industrial production of erythromycin.
Collapse
Affiliation(s)
- Xiaobo Li
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China.,National Food Institute, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Ju Chu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Peter R Jensen
- National Food Institute, Technical University of Denmark, Kongens Lyngby, Denmark
| |
Collapse
|
13
|
Li Y, Dai JY, Xiu ZL. Salting-out extraction of acetoin from fermentation broths using hydroxylammonium ionic liquids as extractants. Sep Purif Technol 2020. [DOI: 10.1016/j.seppur.2020.116584] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
14
|
Xu D, Jia Z, Zhang L, Fu S, Gong H. Analysis of the Growth and Metabolites of a Pyruvate Dehydrogenase Complex- Deficient Klebsiella pneumoniae Mutant in a Glycerol-Based Medium. J Microbiol Biotechnol 2020; 30:753-761. [PMID: 32482942 PMCID: PMC9728353 DOI: 10.4014/jmb.1801.01045] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 05/01/2018] [Indexed: 12/15/2022]
Abstract
To determine the role of pyruvate dehydrogenase complex (PDHC) in Klebsiella pneumoniae, the growth and metabolism of PDHC-deficient mutant in glycerol-based medium were analyzed and compared with those of other strains. Under aerobic conditions, the PDHC activity was fourfold higher than that of pyruvate formate lyase (PFL), and blocking of PDHC caused severe growth defect and pyruvate accumulation, indicating that the carbon flux through pyruvate to acetyl coenzyme A mainly depended on PDHC. Under anaerobic conditions, although the PDHC activity was only 50% of that of PFL, blocking of PDHC resulted in more growth defect than blocking of PFL. Subsequently, combined with the requirement of CO2 and intracellular redox status, it was presumed that the critical role of PDHC was to provide NADH for the anaerobic growth of K. pneumoniae. This presumption was confirmed in the PDHC-deficient mutant by further blocking one of the formate dehydrogenases, FdnGHI. Besides, based on our data, it can also be suggested that an improvement in the carbon flux in the PFL-deficient mutant could be an effective strategy to construct highyielding 1,3-propanediol-producing K. pneumoniae strain.
Collapse
Affiliation(s)
- Danfeng Xu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, P.R. China
| | - Zongxiao Jia
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, P.R. China
| | - Lijuan Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, P.R. China
| | - Shuilin Fu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, P.R. China
| | - Heng Gong
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, P.R. China
| |
Collapse
|
15
|
Engineering of glycerol utilization in Pseudomonas chlororaphis GP72 for enhancing phenazine-1-carboxylic acid production. World J Microbiol Biotechnol 2020; 36:49. [PMID: 32157439 DOI: 10.1007/s11274-020-02824-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 02/29/2020] [Indexed: 12/25/2022]
Abstract
Glycerol is a by-product of biodiesel, and it has a great application prospect to be transformed to synthesize high value-added compounds. Pseudomonas chlororaphis GP72 isolated from the green pepper rhizosphere is a plant growth promoting rhizobacteria that can utilize amount of glycerol to synthesize phenazine-1-carboxylic acid (PCA). PCA has been commercially registered as "Shenqinmycin" in China due to its characteristics of preventing pepper blight and rice sheath blight. The aim of this study was to engineer glycerol utilization pathway in P. chlororaphis GP72. First, the two genes glpF and glpK from the glycerol metabolism pathway were overexpressed in GP72ANO separately. Then, the two genes were co-expressed in GP72ANO, improving PCA production from 729.4 mg/L to 993.4 mg/L at 36 h. Moreover, the shunt pathway was blocked to enhance glycerol utilization, resulting in 1493.3 mg/L PCA production. Additionally, we confirmed the inhibition of glpR on glycerol metabolism pathway in P. chlororaphis GP72. This study provides a good example for improving the utilization of glycerol to synthesize high value-added compounds in Pseudomonas.
Collapse
|
16
|
Lü C, Ge Y, Cao M, Guo X, Liu P, Gao C, Xu P, Ma C. Metabolic Engineering of Bacillus licheniformis for Production of Acetoin. Front Bioeng Biotechnol 2020; 8:125. [PMID: 32154242 PMCID: PMC7047894 DOI: 10.3389/fbioe.2020.00125] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 02/10/2020] [Indexed: 11/13/2022] Open
Abstract
Acetoin is a potential platform compound for a variety of chemicals. Bacillus licheniformis MW3, a thermophilic and generally regarded as safe (GRAS) microorganism, can produce 2,3-butanediol with a high concentration, yield, and productivity. In this study, B. licheniformis MW3 was metabolic engineered for acetoin production. After deleting two 2,3-butanediol dehydrogenases encoding genes budC and gdh, an engineered strain B. licheniformis MW3 (ΔbudCΔgdh) was constructed. Using fed-batch fermentation of B. licheniformis MW3 (ΔbudCΔgdh), 64.2 g/L acetoin was produced at a productivity of 2.378 g/[L h] and a yield of 0.412 g/g from 156 g/L glucose in 27 h. The fermentation process exhibited rather high productivity and yield of acetoin, indicating that B. licheniformis MW3 (ΔbudCΔgdh) might be a promising acetoin producer.
Collapse
Affiliation(s)
- Chuanjuan Lü
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Yongsheng Ge
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Menghao Cao
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Xiaoting Guo
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Peihai Liu
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Chao Gao
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Ping Xu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Cuiqing Ma
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| |
Collapse
|
17
|
Westbrook AW, Miscevic D, Kilpatrick S, Bruder MR, Moo-Young M, Chou CP. Strain engineering for microbial production of value-added chemicals and fuels from glycerol. Biotechnol Adv 2019; 37:538-568. [DOI: 10.1016/j.biotechadv.2018.10.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Revised: 10/03/2018] [Accepted: 10/10/2018] [Indexed: 12/22/2022]
|
18
|
Recent Advances in the Metabolic Engineering of Klebsiella pneumoniae: A Potential Platform Microorganism for Biorefineries. BIOTECHNOL BIOPROC E 2019. [DOI: 10.1007/s12257-018-0346-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
19
|
Zhan Y, Sheng B, Wang H, Shi J, Cai D, Yi L, Yang S, Wen Z, Ma X, Chen S. Rewiring glycerol metabolism for enhanced production of poly-γ-glutamic acid in Bacillus licheniformis. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:306. [PMID: 30455735 PMCID: PMC6225680 DOI: 10.1186/s13068-018-1311-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 11/01/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND Poly-γ-glutamic acid (γ-PGA) is a natural polymer with great potential applications in areas of agriculture, industry, and pharmaceutical. The biodiesel-derived glycerol can be used as an attractive feedstock for γ-PGA production due to its availability and low price; however, insufficient production of γ-PGA from glycerol is limitation. RESULTS The metabolic pathway of Bacillus licheniformis WX-02 was rewired to improve the efficiency of glycerol assimilation and the supply of NADPH for γ-PGA synthesis. GlpK, GlpX, Zwf, and Tkt1 were found to be the key enzymes for γ-PGA synthesis using glycerol as a feedstock. Through combinational expression of these key enzymes, the γ-PGA titer increased to 19.20 ± 1.57 g/L, which was 1.50-fold of that of the wild-type strain. Then, we studied the flux distributions, gene expression, and intracellular metabolites in WX-02 and the recombinant strain BC4 (over-expression of the above quadruple enzymes). Our results indicated that over-expression of the quadruple enzymes redistributed metabolic flux to γ-PGA synthesis. Furthermore, using crude glycerol as carbon source, the BC4 strain showed a high productivity of 0.38 g/L/h, and produced 18.41 g/L γ-PGA, with a high yield of 0.46 g γ-PGA/g glycerol. CONCLUSIONS The approach to rewiring of metabolic pathways enables B. licheniformis to efficiently synthesize γ-PGA from glycerol. The γ-PGA productivity reported in this work is the highest obtained in glutamate-free medium. The present study demonstrates that the recombinant B. licheniformis strain shows significant potential to produce valuable compounds from crude glycerol.
Collapse
Affiliation(s)
- Yangyang Zhan
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuhan, 430062 Hubei People’s Republic of China
| | - Bojie Sheng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
| | - Huan Wang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuhan, 430062 Hubei People’s Republic of China
| | - Jiao Shi
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuhan, 430062 Hubei People’s Republic of China
| | - Dongbo Cai
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuhan, 430062 Hubei People’s Republic of China
| | - Li Yi
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuhan, 430062 Hubei People’s Republic of China
| | - Shihui Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuhan, 430062 Hubei People’s Republic of China
| | - Zhiyou Wen
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
- Department of Food Science and Human Nutrition, Iowa State University, Ames, IA 50011 USA
| | - Xin Ma
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuhan, 430062 Hubei People’s Republic of China
| | - Shouwen Chen
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuhan, 430062 Hubei People’s Republic of China
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
| |
Collapse
|
20
|
A Novel Corynebacterium glutamicum l-Glutamate Exporter. Appl Environ Microbiol 2018; 84:AEM.02691-17. [PMID: 29330181 DOI: 10.1128/aem.02691-17] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 01/07/2018] [Indexed: 01/24/2023] Open
Abstract
Besides metabolic pathways and regulatory networks, transport systems are also pivotal for cellular metabolism and hyperproduction of biochemicals using microbial cell factories. The identification and characterization of transporters are therefore of great significance for the understanding and engineering of transport reactions. Herein, a novel l-glutamate exporter, MscCG2, which exists extensively in Corynebacterium glutamicum strains but is distinct from the only known l-glutamate exporter, MscCG, was discovered in an industrial l-glutamate-producing C. glutamicum strain. MscCG2 was predicted to possess three transmembrane helices in the N-terminal region and located in the cytoplasmic membrane, which are typical structural characteristics of the mechanosensitive channel of small conductance. MscCG2 has a low amino acid sequence identity (23%) to MscCG and evolved separately from MscCG with four transmembrane helices. Despite the considerable differences between MscCG2 and MscCG in sequence and structure, gene deletion and complementation confirmed that MscCG2 also functioned as an l-glutamate exporter and an osmotic safety valve in C. glutamicum Besides, transcriptional analysis showed that MscCG2 and MscCG genes were transcribed in similar patterns and not induced by l-glutamate-producing conditions. It was also demonstrated that MscCG2-mediated l-glutamate excretion was activated by biotin limitation or penicillin treatment and that constitutive l-glutamate excretion was triggered by a gain-of-function mutation of MscCG2 (A151V). Discovery of MscCG2 will enrich the understanding of bacterial amino acid transport and provide additional targets for exporter engineering.IMPORTANCE The exchange of matter, energy, and information with surroundings is fundamental for cellular metabolism. Therefore, studying transport systems that are essential for these processes is of great significance. Besides, transport systems of bacterial cells are usually related to product excretion as well as product reuptake, making transporter engineering a useful strategy for strain improvement. The significance of our research is in identifying and characterizing a novel l-glutamate exporter from the industrial workhorse Corynebacterium glutamicum, which will enrich the understanding of l-glutamate excretion and provide a new target for studying bacterial amino acid transport and engineering transport reactions.
Collapse
|
21
|
Xu Y, Xu C, Li X, Sun B, Eldin AA, Jia Y. A combinational optimization method for efficient synthesis of tetramethylpyrazine by the recombinant Escherichia coli. Biochem Eng J 2018. [DOI: 10.1016/j.bej.2017.10.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
22
|
Dai L, Tao F, Tang H, Guo Y, Shen Y, Xu P. Directing enzyme devolution for biosynthesis of alkanols and 1,n-alkanediols from natural polyhydroxy compounds. Metab Eng 2017; 44:70-80. [DOI: 10.1016/j.ymben.2017.09.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Revised: 09/07/2017] [Accepted: 09/13/2017] [Indexed: 12/01/2022]
|
23
|
Improvement of glycerol catabolism in Bacillus licheniformis for production of poly-γ-glutamic acid. Appl Microbiol Biotechnol 2017; 101:7155-7164. [PMID: 28804802 DOI: 10.1007/s00253-017-8459-2] [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: 01/02/2017] [Revised: 07/08/2017] [Accepted: 07/30/2017] [Indexed: 01/08/2023]
Abstract
Bacillus licheniformis WX-02 is a well-studied strain to produce poly-γ-glutamic acid (γ-PGA) with numerous applications. This study is to improve WX-02 strain's capability of assimilating glycerol, a major byproduct of biofuels industries, through metabolic manipulation. Through gene knockout, the GlpK pathway was identified as the sole functional glycerol catabolism pathway, while the DhaK pathway was inactive for this strain under either aerobic or anaerobic conditions. The enhancement of glycerol utilization was attempted by substituting the native glpFK promoter with the constitutive promoter (P43), ytzE promoter (PytzE), and bacABC operon promoter (PbacA), respectively. The glycerol consumptions of the corresponding mutant strains WX02-P43glpFK, WX02-PytzEglpFK, and WX02-PbacAglpFK were 30.9, 26.42, and 18.8% higher than that of the WX-02 strain, respectively. The γ-PGA concentrations produced by the three mutant strains were 33.71, 23.39, and 30.05% higher than that of WX-02 strain, respectively. When biodiesel-derived crude glycerol was used as the carbon source, the mutant WX02-P43glpFK produced 16.63 g L-1 of γ-PGA, with a productivity of 0.35 g L-1 h-1. Collectively, this study demonstrated that glycerol can be used as an effective substrate for producing γ-PGA by metabolic engineering B. licheniformis strains.
Collapse
|