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Xingya Z, Xiaoping F, Jie Z, Jun Y, Hongchen Z, Wenqin B, Hui S. BsuMI regulates DNA transformation in Bacillus subtilis besides the defense system and the constructed strain with BsuMI-absence is applicable as a universal transformation platform for wild-type Bacillus. Microb Cell Fact 2024; 23:225. [PMID: 39123211 PMCID: PMC11311917 DOI: 10.1186/s12934-024-02493-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2024] [Accepted: 07/29/2024] [Indexed: 08/12/2024] Open
Abstract
BACKGROUND To effectively introduce plasmids into Bacillus species and conduct genetic manipulations in Bacillus chassis strains, it is essential to optimize transformation methods. These methods aim to extend the period of competence and enhance the permeability of the cell membrane to facilitate the entry of exogenous DNA. Although various strategies have been explored, few studies have delved into identifying metabolites and pathways associated with enhanced competence. Additionally, derivative Bacillus strains with non-functional restriction-modification systems have demonstrated superior efficiency in transforming exogenous DNA, lacking more explorations in the regulation conducted by the restriction-modification system to transformation process. RESULTS Transcriptomic comparisons were performed to discover the competence forming mechanism and the regulation pathway conducted by the BsuMI methylation modification group in Bacillus. subtilis 168 under the Spizizen transformation condition, which were speculated to be the preferential selection of carbon sources by the cells and the preference for specific metabolic pathway when utilizing the carbon source. The cells were found to utilize the glycolysis pathway to exploit environmental glucose while reducing the demand for other phosphorylated precursors in this pathway. The weakening of these ATP-substrate competitive metabolic pathways allowed more ATP substrates to be distributed into the auto-phosphorylation of the signal transduction factor ComP during competence formation, thereby increasing the expression level of the key regulatory protein ComK. The expression of ComK upregulated the expression of the negative regulator SacX of starch and sucrose in host cells, reinforcing the preference for glucose as the primary carbon source. The methylation modification group of the primary protein BsuMI in the restriction-modification system was associated with the functional modification of key enzymes in the oxidative phosphorylation pathway. The absence of the BsuMI methylation modification group resulted in a decrease in the expression of subunits of cytochrome oxidase, leading to a weakening of the oxidative phosphorylation pathway, which promoted the glycolytic rate of cells and subsequently improved the distribution of ATP molecules into competence formation. A genetic transformation platform for wild-type Bacillus strains was successfully established based on the constructed strain B. subtilis 168-R-M- without its native restriction-modification system. With this platform, high plasmids transformation efficiencies were achieved with a remarkable 63-fold improvement compared to the control group and an increased universality in Bacillus species was also obtained. CONCLUSIONS The enhanced competence formation mechanism and the regulation pathway conducted by the functional protein BsuMI of the restriction-modification system were concluded, providing a reference for further investigation. An effective transformation platform was established to overcome the obstacles in DNA transformations in wild-type Bacillus strains.
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Affiliation(s)
- Zhao Xingya
- Industrial Enzymes National Engineering Research Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin Airport Economic Area, 32 West 7th Avenue, Tianjin, 300308, China
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin Airport Economic Area, 32 West 7th Avenue, Tianjin, 300308, China
- National Center of Technology Innovation for Synthetic Biology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin Airport Economic Area, 32 West 7th Avenue, Tianjin, 300308, China
| | - Fu Xiaoping
- Industrial Enzymes National Engineering Research Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin Airport Economic Area, 32 West 7th Avenue, Tianjin, 300308, China
- National Center of Technology Innovation for Synthetic Biology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin Airport Economic Area, 32 West 7th Avenue, Tianjin, 300308, China
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin Airport Economic Area, 32 West 7th Avenue, Tianjin, 300308, China
| | - Zhen Jie
- Industrial Enzymes National Engineering Research Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin Airport Economic Area, 32 West 7th Avenue, Tianjin, 300308, China
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin Airport Economic Area, 32 West 7th Avenue, Tianjin, 300308, China
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin Airport Economic Area, 32 West 7th Avenue, Tianjin, 300308, China
| | - Yang Jun
- Industrial Enzymes National Engineering Research Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin Airport Economic Area, 32 West 7th Avenue, Tianjin, 300308, China
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin Airport Economic Area, 32 West 7th Avenue, Tianjin, 300308, China
| | - Zheng Hongchen
- Industrial Enzymes National Engineering Research Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin Airport Economic Area, 32 West 7th Avenue, Tianjin, 300308, China.
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin Airport Economic Area, 32 West 7th Avenue, Tianjin, 300308, China.
- National Center of Technology Innovation for Synthetic Biology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin Airport Economic Area, 32 West 7th Avenue, Tianjin, 300308, China.
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin Airport Economic Area, 32 West 7th Avenue, Tianjin, 300308, China.
| | - Bai Wenqin
- Industrial Enzymes National Engineering Research Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin Airport Economic Area, 32 West 7th Avenue, Tianjin, 300308, China.
- National Center of Technology Innovation for Synthetic Biology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin Airport Economic Area, 32 West 7th Avenue, Tianjin, 300308, China.
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin Airport Economic Area, 32 West 7th Avenue, Tianjin, 300308, China.
| | - Song Hui
- Industrial Enzymes National Engineering Research Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin Airport Economic Area, 32 West 7th Avenue, Tianjin, 300308, China
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin Airport Economic Area, 32 West 7th Avenue, Tianjin, 300308, China
- National Center of Technology Innovation for Synthetic Biology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin Airport Economic Area, 32 West 7th Avenue, Tianjin, 300308, China
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin Airport Economic Area, 32 West 7th Avenue, Tianjin, 300308, China
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Aguilar Suárez R, Kohlstedt M, Öktem A, Neef J, Wu Y, Ikeda K, Yoshida KI, Altenbuchner J, Wittmann C, van Dijl JM. Metabolic Profile of the Genome-Reduced Bacillus subtilis Strain IIG-Bs-27-39: An Attractive Chassis for Recombinant Protein Production. ACS Synth Biol 2024; 13:2199-2214. [PMID: 38981062 PMCID: PMC11264325 DOI: 10.1021/acssynbio.4c00254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2024] [Revised: 06/22/2024] [Accepted: 06/26/2024] [Indexed: 07/11/2024]
Abstract
The Gram-positive bacterium Bacillus subtilis is extensively used in the industry for the secretory production of proteins with commercial value. To further improve its performance, this microbe has been the subject of extensive genome engineering efforts, especially the removal of large genomic regions that are dispensable or even counterproductive. Here, we present the genome-reduced B. subtilis strain IIG-Bs-27-39, which was obtained through systematic deletion of mobile genetic elements, as well as genes for extracellular proteases, sporulation, flagella formation, and antibiotic production. Different from previously characterized genome-reduced B. subtilis strains, the IIG-Bs-27-39 strain was still able to grow on minimal media. We used this feature to benchmark strain IIG-Bs-27-39 against its parental strain 168 with respect to heterologous protein production and metabolic parameters during bioreactor cultivation. The IIG-Bs-27-39 strain presented superior secretion of difficult-to-produce staphylococcal antigens, as well as higher specific growth rates and biomass yields. At the metabolic level, changes in byproduct formation and internal amino acid pools were observed, whereas energetic parameters such as the ATP yield, ATP/ADP levels, and adenylate energy charge were comparable between the two strains. Intriguingly, we observed a significant increase in the total cellular NADPH level during all tested conditions and increases in the NAD+ and NADP(H) pools during protein production. This indicates that the IIG-Bs-27-39 strain has more energy available for anabolic processes and protein production, thereby providing a link between strain physiology and production performance. On this basis, we conclude that the genome-reduced strain IIG-Bs-27-39 represents an attractive chassis for future biotechnological applications.
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Affiliation(s)
- Rocío Aguilar Suárez
- Department
of Medical Microbiology, University Medical
Center Groningen-University of Groningen, 9700RB Groningen, The Netherlands
| | - Michael Kohlstedt
- Institute
for Systems Biotechnology, Saarland University, 66123 Saarbrücken, Germany
| | - Ayşegül Öktem
- Department
of Medical Microbiology, University Medical
Center Groningen-University of Groningen, 9700RB Groningen, The Netherlands
| | - Jolanda Neef
- Department
of Medical Microbiology, University Medical
Center Groningen-University of Groningen, 9700RB Groningen, The Netherlands
| | - Yuzheng Wu
- Department
of Science, Technology and Innovation, Kobe
University, 657-8501 Kobe, Japan
| | - Kaiya Ikeda
- Department
of Science, Technology and Innovation, Kobe
University, 657-8501 Kobe, Japan
| | - Ken-Ichi Yoshida
- Department
of Science, Technology and Innovation, Kobe
University, 657-8501 Kobe, Japan
| | - Josef Altenbuchner
- Institute
for Industrial Genetics, University of Stuttgart, 70569 Stuttgart, Germany
| | - Christoph Wittmann
- Institute
for Systems Biotechnology, Saarland University, 66123 Saarbrücken, Germany
| | - Jan Maarten van Dijl
- Department
of Medical Microbiology, University Medical
Center Groningen-University of Groningen, 9700RB Groningen, The Netherlands
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3
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Put H, Gerstmans H, Vande Capelle H, Fauvart M, Michiels J, Masschelein J. Bacillus subtilis as a host for natural product discovery and engineering of biosynthetic gene clusters. Nat Prod Rep 2024; 41:1113-1151. [PMID: 38465694 DOI: 10.1039/d3np00065f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Covering: up to October 2023Many bioactive natural products are synthesized by microorganisms that are either difficult or impossible to cultivate under laboratory conditions, or that produce only small amounts of the desired compound. By transferring biosynthetic gene clusters (BGCs) into alternative host organisms that are more easily cultured and engineered, larger quantities can be obtained and new analogues with potentially improved biological activity or other desirable properties can be generated. Moreover, expression of cryptic BGCs in a suitable host can facilitate the identification and characterization of novel natural products. Heterologous expression therefore represents a valuable tool for natural product discovery and engineering as it allows the study and manipulation of their biosynthetic pathways in a controlled setting, enabling innovative applications. Bacillus is a genus of Gram-positive bacteria that is widely used in industrial biotechnology as a host for the production of proteins from diverse origins, including enzymes and vaccines. However, despite numerous successful examples, Bacillus species remain underexploited as heterologous hosts for the expression of natural product BGCs. Here, we review important advantages that Bacillus species offer as expression hosts, such as high secretion capacity, natural competence for DNA uptake, and the increasing availability of a wide range of genetic tools for gene expression and strain engineering. We evaluate different strain optimization strategies and other critical factors that have improved the success and efficiency of heterologous natural product biosynthesis in B. subtilis. Finally, future perspectives for using B. subtilis as a heterologous host are discussed, identifying research gaps and promising areas that require further exploration.
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Affiliation(s)
- Hanne Put
- Centre of Microbial and Plant Genetics, KU Leuven, 3001 Leuven, Belgium
- VIB-KU Leuven Center for Microbiology, Flanders Institute for Biotechnology, 3001 Leuven, Belgium.
| | - Hans Gerstmans
- VIB-KU Leuven Center for Microbiology, Flanders Institute for Biotechnology, 3001 Leuven, Belgium.
- Laboratory for Biomolecular Discovery & Engineering, KU Leuven, 3001 Leuven, Belgium
- Biosensors Group, KU Leuven, 3001 Leuven, Belgium
| | - Hanne Vande Capelle
- VIB-KU Leuven Center for Microbiology, Flanders Institute for Biotechnology, 3001 Leuven, Belgium.
- Laboratory for Biomolecular Discovery & Engineering, KU Leuven, 3001 Leuven, Belgium
| | - Maarten Fauvart
- Centre of Microbial and Plant Genetics, KU Leuven, 3001 Leuven, Belgium
- VIB-KU Leuven Center for Microbiology, Flanders Institute for Biotechnology, 3001 Leuven, Belgium.
- imec, 3001 Leuven, Belgium
| | - Jan Michiels
- Centre of Microbial and Plant Genetics, KU Leuven, 3001 Leuven, Belgium
- VIB-KU Leuven Center for Microbiology, Flanders Institute for Biotechnology, 3001 Leuven, Belgium.
| | - Joleen Masschelein
- VIB-KU Leuven Center for Microbiology, Flanders Institute for Biotechnology, 3001 Leuven, Belgium.
- Laboratory for Biomolecular Discovery & Engineering, KU Leuven, 3001 Leuven, Belgium
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4
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Ma S, Su T, Lu X, Qi Q. Bacterial genome reduction for optimal chassis of synthetic biology: a review. Crit Rev Biotechnol 2024; 44:660-673. [PMID: 37380345 DOI: 10.1080/07388551.2023.2208285] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 10/13/2022] [Accepted: 02/20/2023] [Indexed: 06/30/2023]
Abstract
Bacteria with streamlined genomes, that harbor full functional genes for essential metabolic networks, are able to synthesize the desired products more effectively and thus have advantages as production platforms in industrial applications. To obtain streamlined chassis genomes, a large amount of effort has been made to reduce existing bacterial genomes. This work falls into two categories: rational and random reduction. The identification of essential gene sets and the emergence of various genome-deletion techniques have greatly promoted genome reduction in many bacteria over the past few decades. Some of the constructed genomes possessed desirable properties for industrial applications, such as: increased genome stability, transformation capacity, cell growth, and biomaterial productivity. The decreased growth and perturbations in physiological phenotype of some genome-reduced strains may limit their applications as optimized cell factories. This review presents an assessment of the advancements made to date in bacterial genome reduction to construct optimal chassis for synthetic biology, including: the identification of essential gene sets, the genome-deletion techniques, the properties and industrial applications of artificially streamlined genomes, the obstacles encountered in constructing reduced genomes, and the future perspectives.
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Affiliation(s)
- Shuai Ma
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, P. R. China
| | - Tianyuan Su
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, P. R. China
| | - Xuemei Lu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, P. R. China
| | - Qingsheng Qi
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, P. R. China
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5
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Öktem A, Pranoto DA, van Dijl JM. Post-translational secretion stress regulation in Bacillus subtilis is controlled by intra- and extracellular proteases. N Biotechnol 2024; 79:71-81. [PMID: 38158017 DOI: 10.1016/j.nbt.2023.12.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 12/20/2023] [Accepted: 12/26/2023] [Indexed: 01/03/2024]
Abstract
The Gram-positive bacterium Bacillus subtilis is a prolific producer of industrial enzymes that are effectively harvested from the fermentation broth. However, the high capacity of B. subtilis for protein secretion has so far not been exploited to the full due to particular bottlenecks, including product degradation by extracellular proteases and counterproductive secretion stress responses. To unlock the Bacillus secretion pathway for difficult-to-produce proteins, various cellular interventions have been explored, including genome engineering. Our previous research has shown a superior performance of genome-reduced B. subtilis strains in the production of staphylococcal antigens compared to the parental strain 168. This was attributed, at least in part, to redirected secretion stress responses, including the presentation of elevated levels of the quality control proteases HtrA and HtrB that also catalyse protein folding. Here we show that this relates to the elimination of two homologous serine proteases, namely the cytosolic protease AprX and the extracellular protease AprE. This unprecedented posttranslational regulation of secretion stress effectors, like HtrA and HtrB, by the concerted action of cytosolic and extracellular proteases has important implications for the biotechnological application of microbial cell factories. In B. subtilis, this conclusion is underscored by extracellular degradation of the staphylococcal antigen IsaA by both AprX and AprE. Extracellular activity of the cytosolic protease AprX is remarkable since it shows that not only extracellular, but also intracellular proteases impact extracellular product levels. We therefore conclude that intracellular proteases represent new targets for improved recombinant protein production in microbial cell factories like B. subtilis.
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Affiliation(s)
- Ayşegül Öktem
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, the Netherlands
| | - Dicky A Pranoto
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, the Netherlands
| | - Jan Maarten van Dijl
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, the Netherlands.
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6
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Schilling T, Ferrero-Bordera B, Neef J, Maaβ S, Becher D, van Dijl JM. Let There Be Light: Genome Reduction Enables Bacillus subtilis to Produce Disulfide-Bonded Gaussia Luciferase. ACS Synth Biol 2023; 12:3656-3668. [PMID: 38011677 PMCID: PMC10729301 DOI: 10.1021/acssynbio.3c00444] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Revised: 11/09/2023] [Accepted: 11/17/2023] [Indexed: 11/29/2023]
Abstract
Bacillus subtilis is a major workhorse for enzyme production in industrially relevant quantities. Compared to mammalian-based expression systems, B. subtilis presents intrinsic advantages, such as high growth rates, high space-time yield, unique protein secretion capabilities, and low maintenance costs. However, B. subtilis shows clear limitations in the production of biopharmaceuticals, especially proteins from eukaryotic origin that contain multiple disulfide bonds. In the present study, we deployed genome minimization, signal peptide screening, and coexpression of recombinant thiol oxidases as strategies to improve the ability of B. subtilis to secrete proteins with multiple disulfide bonds. Different genome-reduced strains served as the chassis for expressing the model protein Gaussia Luciferase (GLuc), which contains five disulfide bonds. These chassis lack extracellular proteases, prophages, and key sporulation genes. Importantly, compared to the reference strain with a full-size genome, the best-performing genome-minimized strain achieved over 3000-fold increased secretion of active GLuc while growing to lower cell densities. Our results show that high-level GLuc secretion relates, at least in part, to the absence of major extracellular proteases. In addition, we show that the thiol-disulfide oxidoreductase requirements for disulfide bonding have changed upon genome reduction. Altogether, our results highlight genome-engineered Bacillus strains as promising expression platforms for proteins with multiple disulfide bonds.
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Affiliation(s)
- Tobias Schilling
- Department
of Medical Microbiology, University of Groningen,
University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, 9700RB Groningen, The Netherlands
| | - Borja Ferrero-Bordera
- Institute
of Microbiology Department of Microbial Proteomics, University of Greifswald, D-17489 Greifswald, Germany
| | - Jolanda Neef
- Department
of Medical Microbiology, University of Groningen,
University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, 9700RB Groningen, The Netherlands
| | - Sandra Maaβ
- Institute
of Microbiology Department of Microbial Proteomics, University of Greifswald, D-17489 Greifswald, Germany
| | - Dörte Becher
- Institute
of Microbiology Department of Microbial Proteomics, University of Greifswald, D-17489 Greifswald, Germany
| | - Jan Maarten van Dijl
- Department
of Medical Microbiology, University of Groningen,
University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, 9700RB Groningen, The Netherlands
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7
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Liu Y, Cheng H, Li H, Zhang Y, Wang M. A Programmable CRISPR/Cas9 Toolkit Improves Lycopene Production in Bacillus subtilis. Appl Environ Microbiol 2023; 89:e0023023. [PMID: 37272803 PMCID: PMC10305015 DOI: 10.1128/aem.00230-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 05/16/2023] [Indexed: 06/06/2023] Open
Abstract
Bacillus subtilis has been widely used and generally recognized as a safe host for the production of recombinant proteins, high-value chemicals, and pharmaceuticals. Thus, its metabolic engineering attracts significant attention. Nevertheless, the limited availability of selective markers makes this process difficult and time-consuming, especially in the case of multistep biosynthetic pathways. Here, we employ CRISPR/Cas9 technology to build an easy cloning toolkit that addresses commonly encountered obstacles in the metabolic engineering of B. subtilis, including the chromosomal integration locus, promoter, terminator, and guide RNA (gRNA) target. Six promoters were characterized, and the promoter strengths ranged from 0.9- to 23-fold that of the commonly used strong promoter P43. We characterized seven terminators in B. subtilis, and the termination efficiencies (TEs) of the seven terminators are all more than 90%. Six gRNA targets were designed upstream of the promoter and downstream of the terminator. Using a green fluorescent protein (GFP) reporter, we confirmed integration efficiency with the single-locus integration site is up to 100%. We demonstrated the applicability of this toolkit by optimizing the expression of a challenging but industrially important product, lycopene. By heterologous expression of the essential genes for lycopene synthesis on the B. subtilis genome, a total of 13 key genes involved in the lycopene biosynthetic pathway were manipulated. Moreover, our findings showed that the gene cluster ispG-idi-dxs-ispD could positively affect the production of lycopene, while the cluster dxr-ispE-ispF-ispH had a negative effect on lycopene production. Hence, our multilocus integration strategy can facilitate the pathway assembly for production of complex chemicals and pharmaceuticals in B. subtilis. IMPORTANCE We present a toolkit that allows for rapid cloning procedures and one-step subcloning to move from plasmid-based expression to stable chromosome integration and expression in a production strain in less than a week. The utility of the customized tool was demonstrated by integrating the MEP (2C-methyl-d-erythritol-4-phosphate) pathway, part of the pentose phosphate pathway (PPP), and the hetero-lycopene biosynthesis genes by stable expression in the genome. The tool could be useful to engineer B. subtilis strains through diverse recombination events and ultimately improve its potential and scope of industrial application as biological chassis.
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Affiliation(s)
- Yang Liu
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Haijiao Cheng
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Haoni Li
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Yingzhe Zhang
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Meng Wang
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
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Hoffmann K, Halmschlag B, Briel S, Sieben M, Putri S, Fukusaki E, Blank LM, Büchs J. Online measurement of the viscosity in shake flasks enables monitoring of γ-PGA production in depolymerase knockout mutants of Bacillus subtilis with the phosphate-starvation inducible promoter P pst. Biotechnol Prog 2023; 39:e3293. [PMID: 36081345 DOI: 10.1002/btpr.3293] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 07/26/2022] [Accepted: 08/11/2022] [Indexed: 11/10/2022]
Abstract
Poly-γ-glutamic acid (γ-PGA) is a biopolymer with a wide range of applications, mainly produced using Bacillus strains. The formation and concomitant secretion of γ-PGA increases the culture broth viscosity, while enzymatic depolymerisation and degradation of γ-PGA decreases the culture broth viscosity. In this study, the recently published ViMOS (Viscosity Monitoring Online System) is applied for optical online measurements of broth viscosity in eight parallel shake flasks. It is shown that the ViMOS is suitable to monitor γ-PGA production and degradation online in shake flasks. This online monitoring enables the detailed analysis of the Ppst promoter and γ-PGA depolymerase knockout mutants in genetically modified Bacillus subtilis 168. The Ppst promoter becomes active under phosphate starvation. The different single depolymerase knockout mutants are ∆ggt, ∆pgdS, ∆cwlO and a triple knockout mutant. An increase in γ-PGA yield in gγ-PGA /gglucose of 190% could be achieved with the triple knockout mutant compared to the Ppst reference strain. The single cwlO knockout also increased γ-PGA production, while the other single knockouts of ggt and pgdS showed no impact. Partial depolymerisation of γ-PGA occurred despite the triple knockout. The online measured data are confirmed with offline measurements. The online viscosity system directly reflects γ-PGA synthesis, γ-PGA depolymerisation, and changes in the molecular weight. Thus, the ViMOS has great potential to rapidly gain detailed and reliable information about new strains and cultivation conditions. The broadened knowledge will facilitate the further optimization of γ-PGA production.
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Affiliation(s)
- Kyra Hoffmann
- AVT - Biochemical Engineering, RWTH Aachen University, Aachen, Germany
| | - Birthe Halmschlag
- Institute of Applied Microbiology - iAMB, Aachen Biology and Biotechnology - ABBt, RWTH Aachen University, Aachen, Germany
| | - Simon Briel
- AVT - Biochemical Engineering, RWTH Aachen University, Aachen, Germany
| | - Michaela Sieben
- AVT - Biochemical Engineering, RWTH Aachen University, Aachen, Germany
| | - Sastia Putri
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan
| | - Eiichiro Fukusaki
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan
| | - Lars M Blank
- Institute of Applied Microbiology - iAMB, Aachen Biology and Biotechnology - ABBt, RWTH Aachen University, Aachen, Germany
| | - Jochen Büchs
- AVT - Biochemical Engineering, RWTH Aachen University, Aachen, Germany
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9
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Tian J, Xing B, Li M, Xu C, Huo YX, Guo S. Efficient Large-Scale and Scarless Genome Engineering Enables the Construction and Screening of Bacillus subtilis Biofuel Overproducers. Int J Mol Sci 2022; 23:ijms23094853. [PMID: 35563243 PMCID: PMC9099979 DOI: 10.3390/ijms23094853] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/17/2022] [Accepted: 04/26/2022] [Indexed: 11/16/2022] Open
Abstract
Bacillus subtilis is a versatile microbial cell factory that can produce valuable proteins and value-added chemicals. Long fragment editing techniques are of great importance for accelerating bacterial genome engineering to obtain desirable and genetically stable host strains. Herein, we develop an efficient CRISPR-Cas9 method for large-scale and scarless genome engineering in the Bacillus subtilis genome, which can delete up to 134.3 kb DNA fragments, 3.5 times as long as the previous report, with a positivity rate of 100%. The effects of using a heterologous NHEJ system, linear donor DNA, and various donor DNA length on the engineering efficiencies were also investigated. The CRISPR-Cas9 method was then utilized for Bacillus subtilis genome simplification and construction of a series of individual and cumulative deletion mutants, which are further screened for overproducer of isobutanol, a new generation biofuel. These results suggest that the method is a powerful genome engineering tool for constructing and screening engineered host strains with enhanced capabilities, highlighting the potential for synthetic biology and metabolic engineering.
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Redirected Stress Responses in a Genome-Minimized 'midi Bacillus' Strain with Enhanced Capacity for Protein Secretion. mSystems 2021; 6:e0065521. [PMID: 34904864 PMCID: PMC8670375 DOI: 10.1128/msystems.00655-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Genome engineering offers the possibility to create completely novel cell factories with enhanced properties for biotechnological applications. In recent years, genome minimization was extensively explored in the Gram-positive bacterial cell factory Bacillus subtilis, where up to 42% of the genome encoding dispensable functions was removed. Such studies showed that some strains with minimized genomes gained beneficial features, especially for secretory protein production. However, strains with the most minimal genomes displayed growth defects. This focused our attention on strains with less extensive genomic deletions that display close-to-wild-type growth properties while retaining the acquired beneficial traits in secretory protein production. A strain of this category is B. subtilis IIG-Bs27-47-24, here referred to as midiBacillus, which lacks 30.95% of the parental genome. To date, it was unknown how the altered genomic configuration of midiBacillus impacts cell physiology in general, and protein secretion in particular. The present study bridges this knowledge gap through comparative quantitative proteome analyses with focus on protein secretion. Interestingly, the results show that the secretion stress responses of midiBacillus, as elicited by high-level expression of the immunodominant staphylococcal antigen A, are completely different from secretion stress responses that occur in the parental strain 168. We further show that midiBacillus has an increased capacity for translation and that a variety of critical Sec secretion machinery components is present at elevated levels. Altogether, our observations demonstrate that high-level protein secretion has different consequences for wild-type and genome-engineered Bacillus strains, dictated by the altered genomic and proteomic configurations. IMPORTANCE Our present study showcases a genome-minimized nonpathogenic bacterium, the so-called midiBacillus, as a chassis for the development of future industrial strains that serve in the production of high-value difficult-to-produce proteins. In particular, we explain how midiBacillus, which lacks about one-third of the original genome, effectively secretes a protein of the major human pathogen Staphylococcus aureus that cannot be produced by the parental Bacillus subtilis strain. This is important, because the secreted S. aureus protein is exemplary for a range of targets that can be implemented in future antistaphylococcal immunotherapies. Accordingly, we anticipate that midiBacillus chassis will contribute to the development of vaccines that protect both humans and livestock against diseases caused by S. aureus, a bacterial pathogen that is increasingly difficult to fight with antibiotics, because it has accumulated resistances to essentially all antibiotics that are currently in clinical practice.
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Sutton G, Fogel GB, Abramson B, Brinkac L, Michael T, Liu ES, Thomas S. A pan-genome method to determine core regions of the Bacillus subtilis and Escherichia coli genomes. F1000Res 2021; 10:286. [PMID: 34113437 PMCID: PMC8156514 DOI: 10.12688/f1000research.51873.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/17/2021] [Indexed: 11/22/2022] Open
Abstract
Background: Synthetic engineering of bacteria to produce industrial products is a burgeoning field of research and application. In order to optimize genome design, designers need to understand which genes are essential, which are optimal for growth, and locations in the genome that will be tolerated by the organism when inserting engineered cassettes. Methods: We present a pan-genome based method for the identification of core regions in a genome that are strongly conserved at the species level. Results: We show that the core regions determined by our method contain all or almost all essential genes. This demonstrates the accuracy of our method as essential genes should be core genes. We show that we outperform previous methods by this measure. We also explain why there are exceptions to this rule for our method. Conclusions: We assert that synthetic engineers should avoid deleting or inserting into these core regions unless they understand and are manipulating the function of the genes in that region. Similarly, if the designer wishes to streamline the genome, non-core regions and in particular low penetrance genes would be good targets for deletion. Care should be taken to remove entire cassettes with similar penetrance of the genes within cassettes as they may harbor toxin/antitoxin genes which need to be removed in tandem. The bioinformatic approach introduced here saves considerable time and effort relative to knockout studies on single isolates of a given species and captures a broad understanding of the conservation of genes that are core to a species.
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Affiliation(s)
- Granger Sutton
- J. Craig Venter Institute, Rockville, Maryland, 20850, USA
| | - Gary B Fogel
- Natural Selection, Inc., San Diego, CA, 92121, USA
| | | | | | - Todd Michael
- J. Craig Venter Institute, Rockville, Maryland, 20850, USA
| | - Enoch S Liu
- Natural Selection, Inc., San Diego, CA, 92121, USA
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12
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Appelbaum M, Schweder T. Metabolic Engineering of
Bacillus
– New Tools, Strains, and Concepts. Metab Eng 2021. [DOI: 10.1002/9783527823468.ch13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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13
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Hoffmann M, Braig A, Fernandez Cano Luna DS, Rief K, Becker P, Treinen C, Klausmann P, Morabbi Heravi K, Henkel M, Lilge L, Hausmann R. Evaluation of an oxygen-dependent self-inducible surfactin synthesis in B. subtilis by substitution of native promoter P srfA by anaerobically active P narG and P nasD. AMB Express 2021; 11:57. [PMID: 33876328 PMCID: PMC8055807 DOI: 10.1186/s13568-021-01218-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 04/07/2021] [Indexed: 01/09/2023] Open
Abstract
A novel approach targeting self-inducible surfactin synthesis under oxygen-limited conditions is presented. Because both the nitrate (NarGHI) and nitrite (NasDE) reductase are highly expressed during anaerobic growth of B. subtilis, the native promoter PsrfA of the surfactin operon in strain B. subtilis JABs24 was replaced by promoters PnarG and PnasD to induce surfactin synthesis anaerobically. Shake flask cultivations with varying oxygen availabilities indicated no significant differences in native PsrfA expression. As hypothesized, activity of PnarG and PnasD increased with lower oxygen levels and surfactin was not produced by PsrfA::PnarG as well as PsrfA::PnasD mutant strains under conditions with highest oxygen availability. PnarG showed expressions similar to PsrfA at lowest oxygen availability, while maximum value of PnasD was more than 5.5-fold higher. Although the promoter exchange PsrfA::PnarG resulted in a decreased surfactin titer at lowest oxygen availability, the strain carrying PsrfA::PnasD reached a 1.4-fold increased surfactin concentration with 696 mg/L and revealed an exceptional high overall YP/X of 1.007 g/g. This value also surpassed the YP/X of the reference strain JABs24 at highest and moderate oxygen availability. Bioreactor cultivations illustrated that significant cell lysis occurred when the process of "anaerobization" was performed too fast. However, processes with a constantly low agitation and aeration rate showed promising potential for process improvement, especially by employing the strain carrying PsrfA::PnasD promoter exchange. Additionally, replacement of other native promoters by nitrite reductase promoter PnasD represents a promising tool for anaerobic-inducible bioprocesses in Bacillus.
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Affiliation(s)
- Mareen Hoffmann
- Institute of Food Science and Biotechnology (150), Department of Bioprocess Engineering (150k), University of Hohenheim, Fruwirthstr. 12, 70599, Stuttgart, Germany
| | - Alina Braig
- Institute of Food Science and Biotechnology (150), Department of Bioprocess Engineering (150k), University of Hohenheim, Fruwirthstr. 12, 70599, Stuttgart, Germany
| | - Diana Stephanie Fernandez Cano Luna
- Institute of Food Science and Biotechnology (150), Department of Bioprocess Engineering (150k), University of Hohenheim, Fruwirthstr. 12, 70599, Stuttgart, Germany
| | - Katharina Rief
- Institute of Food Science and Biotechnology (150), Department of Bioprocess Engineering (150k), University of Hohenheim, Fruwirthstr. 12, 70599, Stuttgart, Germany
| | - Philipp Becker
- Institute of Food Science and Biotechnology (150), Department of Bioprocess Engineering (150k), University of Hohenheim, Fruwirthstr. 12, 70599, Stuttgart, Germany
| | - Chantal Treinen
- Institute of Food Science and Biotechnology (150), Department of Bioprocess Engineering (150k), University of Hohenheim, Fruwirthstr. 12, 70599, Stuttgart, Germany
| | - Peter Klausmann
- Institute of Food Science and Biotechnology (150), Department of Bioprocess Engineering (150k), University of Hohenheim, Fruwirthstr. 12, 70599, Stuttgart, Germany
| | - Kambiz Morabbi Heravi
- Institute of Food Science and Biotechnology (150), Department of Bioprocess Engineering (150k), University of Hohenheim, Fruwirthstr. 12, 70599, Stuttgart, Germany
| | - Marius Henkel
- Institute of Food Science and Biotechnology (150), Department of Bioprocess Engineering (150k), University of Hohenheim, Fruwirthstr. 12, 70599, Stuttgart, Germany
| | - Lars Lilge
- Institute of Food Science and Biotechnology (150), Department of Bioprocess Engineering (150k), University of Hohenheim, Fruwirthstr. 12, 70599, Stuttgart, Germany.
| | - Rudolf Hausmann
- Institute of Food Science and Biotechnology (150), Department of Bioprocess Engineering (150k), University of Hohenheim, Fruwirthstr. 12, 70599, Stuttgart, Germany
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14
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Sutton G, Fogel GB, Abramson B, Brinkac L, Michael T, Liu ES, Thomas S. A pan-genome method to determine core regions of the Bacillus subtilis and Escherichia coli genomes. F1000Res 2021; 10:286. [DOI: 10.12688/f1000research.51873.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/31/2021] [Indexed: 11/20/2022] Open
Abstract
Background: Synthetic engineering of bacteria to produce industrial products is a burgeoning field of research and application. In order to optimize genome design, designers need to understand which genes are essential, which are optimal for growth, and locations in the genome that will be tolerated by the organism when inserting engineered cassettes. Methods: We present a pan-genome based method for the identification of core regions in a genome that are strongly conserved at the species level. Results: We show that the core regions determined by our method contain all or almost all essential genes. This demonstrates the accuracy of our method as essential genes should be core genes. We show that we outperform previous methods by this measure. We also explain why there are exceptions to this rule for our method. Conclusions: We assert that synthetic engineers should avoid deleting or inserting into these core regions unless they understand and are manipulating the function of the genes in that region. Similarly, if the designer wishes to streamline the genome, non-core regions and in particular low penetrance genes would be good targets for deletion. Care should be taken to remove entire cassettes with similar penetrance of the genes within cassettes as they may harbor toxin/antitoxin genes which need to be removed in tandem. The bioinformatic approach introduced here saves considerable time and effort relative to knockout studies on single isolates of a given species and captures a broad understanding of the conservation of genes that are core to a species.
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15
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Fragment Exchange Plasmid Tools for CRISPR/Cas9-Mediated Gene Integration and Protease Production in Bacillus subtilis. Appl Environ Microbiol 2020; 87:AEM.02090-20. [PMID: 33097498 PMCID: PMC7755240 DOI: 10.1128/aem.02090-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 10/14/2020] [Indexed: 12/26/2022] Open
Abstract
We complemented a cloning platform with new editing plasmids that allow a quick transition from high-throughput cloning and the expression of new enzymes to the stable integration of genes for the production of enzymes through B. subtilis fermentation. We present two systems for the effective assembly cloning of any genome-editing cassette that shortens the engineering procedure to obtain the final editing constructs. The utility of the customized tools is demonstrated by disrupting Bacillus’ capacity to sporulate and by introducing the stable expression of subtilisin. The tools should be useful to engineer B. subtilis strains by a variety of recombination events to ultimately improve the application range of this industry-relevant host. Since its discovery as part of the bacterial adaptative immune system, CRISPR/Cas has emerged as the most promising tool for targeted genome editing over the past few years. Various tools for genome editing in Bacillus subtilis have recently been developed, expanding and simplifying its potential development as an industrial species. A collection of vectors compatible with high-throughput (HTP) fragment exchange (FX) cloning for heterologous expression in Escherichia coli and Bacillus was previously developed. This vector catalogue was through this work supplemented with editing plasmids for genome engineering in Bacillus by adapting two CRISPR/Cas plasmids to the cloning technology. The customized tools allow versatile editing at any chosen genomic position (single-plasmid strategy) or at a fixed genomic locus (double-plasmid strategy). The single-plasmid strategy was validated by deleting the spoIIAC gene, which has an essential role in sporulation. Using the double-plasmid strategy, we demonstrate the quick transition from plasmid-based subtilisin expression to the stable integration of the gene into the amyE locus of a seven-protease-deficient KO7 strain. The newly engineered B. subtilis strain allowed the successful production of a functional enzyme. The customized tools provide improvements to the cloning procedure, should be useful for versatile genomic engineering, and contribute to a cloning platform for a quick transition from HTP enzyme expression to production through the fermentation of industrially relevant B. subtilis and related strains. IMPORTANCE We complemented a cloning platform with new editing plasmids that allow a quick transition from high-throughput cloning and the expression of new enzymes to the stable integration of genes for the production of enzymes through B. subtilis fermentation. We present two systems for the effective assembly cloning of any genome-editing cassette that shortens the engineering procedure to obtain the final editing constructs. The utility of the customized tools is demonstrated by disrupting Bacillus’ capacity to sporulate and by introducing the stable expression of subtilisin. The tools should be useful to engineer B. subtilis strains by a variety of recombination events to ultimately improve the application range of this industry-relevant host.
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16
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Vahidinasab M, Lilge L, Reinfurt A, Pfannstiel J, Henkel M, Morabbi Heravi K, Hausmann R. Construction and description of a constitutive plipastatin mono-producing Bacillus subtilis. Microb Cell Fact 2020; 19:205. [PMID: 33167976 PMCID: PMC7654001 DOI: 10.1186/s12934-020-01468-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 10/29/2020] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Plipastatin is a potent Bacillus antimicrobial lipopeptide with the prospect to replace conventional antifungal chemicals for controlling plant pathogens. However, the application of this lipopeptide has so far been investigated in a few cases, principally because of the yield in low concentration and unknown regulation of biosynthesis pathways. B. subtilis synthesizes plipastatin by a non-ribosomal peptide synthetase encoded by the ppsABCDE operon. In this study, B. subtilis 3NA (a non-sporulation strain) was engineered to gain more insights about plipastatin mono-production. RESULTS The 4-phosphopantetheinyl transferase Sfp posttranslationally converts non-ribosomal peptide synthetases from inactive apoforms into their active holoforms. In case of 3NA strain, sfp gene is inactive. Accordingly, the first step was an integration of a repaired sfp version in 3NA to construct strain BMV9. Subsequently, plipastatin production was doubled after integration of a fully expressed degQ version from B. subtilis DSM10T strain (strain BMV10), ensuring stimulation of DegU-P regulatory pathway that positively controls the ppsABSDE operon. Moreover, markerless substitution of the comparably weak native plipastatin promoter (Ppps) against the strong constitutive promoter Pveg led to approximately fivefold enhancement of plipastatin production in BMV11 compared to BMV9. Intriguingly, combination of both repaired degQ expression and promoter exchange (Ppps::Pveg) did not increase the plipastatin yield. Afterwards, deletion of surfactin (srfAA-AD) operon by the retaining the regulatory comS which is located within srfAB and is involved in natural competence development, resulted in the loss of plipastatin production in BMV9 and significantly decreased the plipastatin production of BMV11. We also observed that supplementation of ornithine as a precursor for plipastatin formation caused higher production of plipastatin in mono-producer strains, albeit with a modified pattern of plipastatin composition. CONCLUSIONS This study provides evidence that degQ stimulates the native plipastatin production. Moreover, a full plipastatin production requires surfactin synthetase or some of its components. Furthermore, as another conclusion of this study, results point towards ornithine provision being an indispensable constituent for a plipastatin mono-producer B. subtilis strain. Therefore, targeting the ornithine metabolic flux might be a promising strategy to further investigate and enhance plipastatin production by B. subtilis plipastatin mono-producer strains.
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Affiliation(s)
- Maliheh Vahidinasab
- Institute of Food Science and Biotechnology, Department of Bioprocess Engineering (150K), University of Hohenheim, Fruwirthstraße 12, 70599, Stuttgart, Germany
| | - Lars Lilge
- Institute of Food Science and Biotechnology, Department of Bioprocess Engineering (150K), University of Hohenheim, Fruwirthstraße 12, 70599, Stuttgart, Germany.
| | - Aline Reinfurt
- Institute of Food Science and Biotechnology, Department of Bioprocess Engineering (150K), University of Hohenheim, Fruwirthstraße 12, 70599, Stuttgart, Germany
| | - Jens Pfannstiel
- Core Facility Hohenheim, Mass Spectrometry Unit, University of Hohenheim, August-von-Hartmann-Str. 3, 70599, Stuttgart, Germany
| | - Marius Henkel
- Institute of Food Science and Biotechnology, Department of Bioprocess Engineering (150K), University of Hohenheim, Fruwirthstraße 12, 70599, Stuttgart, Germany
| | - Kambiz Morabbi Heravi
- Institute of Food Science and Biotechnology, Department of Bioprocess Engineering (150K), University of Hohenheim, Fruwirthstraße 12, 70599, Stuttgart, Germany
| | - Rudolf Hausmann
- Institute of Food Science and Biotechnology, Department of Bioprocess Engineering (150K), University of Hohenheim, Fruwirthstraße 12, 70599, Stuttgart, Germany
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17
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Poly-γ-glutamic acid production by Bacillus subtilis 168 using glucose as the sole carbon source: A metabolomic analysis. J Biosci Bioeng 2020; 130:272-282. [DOI: 10.1016/j.jbiosc.2020.04.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 04/22/2020] [Accepted: 04/26/2020] [Indexed: 11/18/2022]
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18
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Machinandiarena F, Nakamatsu L, Schujman GE, de Mendoza D, Albanesi D. Revisiting the coupling of fatty acid to phospholipid synthesis in bacteria with FapR regulation. Mol Microbiol 2020; 114:653-663. [PMID: 32671874 DOI: 10.1111/mmi.14574] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 07/07/2020] [Accepted: 07/11/2020] [Indexed: 12/31/2022]
Abstract
A key aspect in membrane biogenesis is the coordination of fatty acid to phospholipid synthesis rates. In most bacteria, PlsX is the first enzyme of the phosphatidic acid synthesis pathway, the common precursor of all phospholipids. Previously, we proposed that PlsX is a key regulatory point that synchronizes the fatty acid synthase II with phospholipid synthesis in Bacillus subtilis. However, understanding the basis of such coordination mechanism remained a challenge in Gram-positive bacteria. Here, we show that the inhibition of fatty acid and phospholipid synthesis caused by PlsX depletion leads to the accumulation of long-chain acyl-ACPs, the end products of the fatty acid synthase II. Hydrolysis of the acyl-ACP pool by heterologous expression of a cytosolic thioesterase relieves the inhibition of fatty acid synthesis, indicating that acyl-ACPs are feedback inhibitors of this metabolic route. Unexpectedly, inactivation of PlsX triggers a large increase of malonyl-CoA leading to induction of the fap regulon. This finding discards the hypothesis, proposed for B. subtilis and extended to other Gram-positive bacteria, that acyl-ACPs are feedback inhibitors of the acetyl-CoA carboxylase. Finally, we propose that the continuous production of malonyl-CoA during phospholipid synthesis inhibition provides an additional mechanism for fine-tuning the coupling between phospholipid and fatty acid production in bacteria with FapR regulation.
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Affiliation(s)
- Federico Machinandiarena
- Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Leandro Nakamatsu
- División de Biología Sintética, Ingeniería Metabólica SA (INMET), Rosario, Argentina
| | - Gustavo E Schujman
- División de Biología Sintética, Ingeniería Metabólica SA (INMET), Rosario, Argentina.,CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Diego de Mendoza
- Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Daniela Albanesi
- Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
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19
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Halmschlag B, Putri SP, Fukusaki E, Blank LM. Identification of Key Metabolites in Poly-γ-Glutamic Acid Production by Tuning γ-PGA Synthetase Expression. Front Bioeng Biotechnol 2020; 8:38. [PMID: 32083073 PMCID: PMC7002566 DOI: 10.3389/fbioe.2020.00038] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 01/16/2020] [Indexed: 11/13/2022] Open
Abstract
Poly-γ-glutamic acid (γ-PGA) production is commonly achieved using glycerol, citrate, and L-glutamic acid as substrates. The constitutive expression of the γ-PGA synthetase enabled γ-PGA production with Bacillus subtilis from glucose only. The precursors for γ-PGA synthesis, D- and L-glutamate, are ubiquitous metabolites. Hence, the metabolic flux toward γ-PGA directly depends on the concentration and activity of the synthetase and thereby on its expression. To identify pathway bottlenecks and important metabolites that are highly correlated with γ-PGA production from glucose, we engineered B. subtilis strains with varying γ-PGA synthesis rates. To alter the rate of γ-PGA synthesis, the expression level was controlled by two approaches: (1) Using promoter variants from the constitutive promoter P veg and (2) Varying induction strength of the xylose inducible promoter P xyl . The variation in the metabolism caused by γ-PGA production was investigated using metabolome analysis. The xylose-induction strategy revealed that the γ-PGA production rate increased the total fluxes through metabolism indicating a driven by demand adaption of the metabolism. Metabolic bottlenecks during γ-PGA from glucose were identified by generation of a model that correlates γ-PGA production rate with intracellular metabolite levels. The generated model indicates the correlation of certain metabolites such as phosphoenolpyruvate with γ-PGA production. The identified metabolites are targets for strain improvement to achieve high level γ-PGA production from glucose.
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Affiliation(s)
- Birthe Halmschlag
- Institute of Applied Microbiology-iAMB, Aachen Biology and Biotechnology-ABBt, RWTH Aachen University, Aachen, Germany
| | - Sastia P. Putri
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Osaka, Japan
| | - Eiichiro Fukusaki
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Osaka, Japan
| | - Lars M. Blank
- Institute of Applied Microbiology-iAMB, Aachen Biology and Biotechnology-ABBt, RWTH Aachen University, Aachen, Germany
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20
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Halmschlag B, Hoffmann K, Hanke R, Putri SP, Fukusaki E, Büchs J, Blank LM. Comparison of Isomerase and Weimberg Pathway for γ-PGA Production From Xylose by Engineered Bacillus subtilis. Front Bioeng Biotechnol 2020; 7:476. [PMID: 32039180 PMCID: PMC6985040 DOI: 10.3389/fbioe.2019.00476] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 12/23/2019] [Indexed: 11/13/2022] Open
Abstract
The production of poly-γ-glutamic acid (γ-PGA), a biopolymer consisting of D- and L-glutamic acid monomers, currently relies on L-glutamate, or citrate as carbon substrates. Here we aimed at using plant biomass-derived substrates such as xylose. γ-PGA producing microorganisms including Bacillus subtilis natively metabolize xylose via the isomerase pathway. The Weimberg pathway, a xylose utilization pathway first described for Caulobacter crescentus, offers a carbon-efficient alternative converting xylose to 2-oxoglutarate without carbon loss. We engineered a recombinant B. subtilis strain that was able to grow on xylose with a growth rate of 0.43 h-1 using a recombinant Weimberg pathway. Although ion-pair reversed-phase LC/MS/MS metabolome analysis revealed lower concentrations of γ-PGA precursors such as 2-oxoglutarate, the γ-PGA titer was increased 6-fold compared to the native xylose isomerase strain. Further metabolome analysis indicates a metabolic bottleneck in the phosphoenolpyruvate-pyruvate-oxaloacetate node causing bi-phasic (diauxic) growth of the recombinant Weimberg strain. Flux balance analysis (FBA) of the γ-PGA producing B. subtilis indicated that a maximal theoretical γ-PGA yield is achieved on D-xylose/ D-glucose mixtures. The results of the B. subtilis strain harboring the Weimberg pathway on such D-xylose/ D-glucose mixtures demonstrate indeed resource efficient, high yield γ-PGA production from biomass-derived substrates.
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Affiliation(s)
- Birthe Halmschlag
- Institute of Applied Microbiology, Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany
| | - Kyra Hoffmann
- AVT-Biochemical Engineering, RWTH Aachen University, Aachen, Germany
| | - René Hanke
- AVT-Biochemical Engineering, RWTH Aachen University, Aachen, Germany
| | - Sastia P Putri
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Osaka, Japan
| | - Eiichiro Fukusaki
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Osaka, Japan
| | - Jochen Büchs
- AVT-Biochemical Engineering, RWTH Aachen University, Aachen, Germany
| | - Lars M Blank
- Institute of Applied Microbiology, Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany
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21
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van Tilburg AY, Cao H, van der Meulen SB, Solopova A, Kuipers OP. Metabolic engineering and synthetic biology employing Lactococcus lactis and Bacillus subtilis cell factories. Curr Opin Biotechnol 2019; 59:1-7. [DOI: 10.1016/j.copbio.2019.01.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 12/05/2018] [Accepted: 01/16/2019] [Indexed: 12/11/2022]
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22
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Watzlawick H, Altenbuchner J. Multiple integration of the gene ganA into the Bacillus subtilis chromosome for enhanced β-galactosidase production using the CRISPR/Cas9 system. AMB Express 2019; 9:158. [PMID: 31571017 PMCID: PMC6768931 DOI: 10.1186/s13568-019-0884-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Accepted: 09/21/2019] [Indexed: 01/18/2023] Open
Abstract
The ganA gene from Bacillus subtilis encoding a β-galactosidase for degradation of the galactomannan was integrated in different loci of the B. subtilis chromosome employing the CRISPR/Cas9 system. Hereby a total of five copies of ganA cassettes in which the ganA gene was fused with the glucitol-promoter were inserted in the recipient chromosome wherein hypothetical, sporulation and protease genes were deleted. The strain with five copies of ganA expression cassette showed a β-galactosidase activity similar to the one with the same gene on a pUB110 derived multi-copy plasmid and under the same regulatory control of the glucitol promoter and GutR activator. The production of β-galactosidase in the strain with the multi-copy plasmid decreased rapidly when growth was performed under induced conditions and without antibiotic selection. In contrast, the strain with the five copies of ganA in the chromosome produced β-galactosidase for at least 40 generations. This demonstrates that the CRISPR/Cas9 system is a valuable and easy tool for constructing stable producer strains. The bigger efforts that are needed for the multiple target gene integration into the chromosome compared to cloning in expression vectors were justified by the higher stability of the target genes and the lack of antibiotic resistance genes.
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Toymentseva AA, Altenbuchner J. New CRISPR-Cas9 vectors for genetic modifications of Bacillus species. FEMS Microbiol Lett 2019; 366:5232309. [PMID: 30520985 DOI: 10.1093/femsle/fny284] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 12/05/2018] [Indexed: 12/16/2022] Open
Abstract
Genetic manipulation is a fundamental procedure for the study of gene and operon functions and new characteristics acquisition. Modern CRISPR-Cas technology allows genome editing more precisely and increases the efficiency of transferring mutations in a variety of hard to manipulate organisms. Here, we describe new CRISPR-Cas vectors for genetic modifications in bacillary species. Our plasmids are single CRISPR-Cas plasmids comprising all components for genome editing and should be functional in a broad host range. They are highly efficient (up to 97%) and precise. The employment and delivery of these plasmids to bacillary strains can be easily achieved by conjugation from Escherichia coli. During our research we also demonstrated the absence of compatibility between CRISPR-Cas system and non-homologous end joining in Bacillus subtilis.
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Affiliation(s)
- Anna A Toymentseva
- Institut für Industrielle Genetik, Universität Stuttgart, Allmandring 31, 70569 Stuttgart, Germany
| | - Josef Altenbuchner
- Institut für Industrielle Genetik, Universität Stuttgart, Allmandring 31, 70569 Stuttgart, Germany
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Wynands B, Otto M, Runge N, Preckel S, Polen T, Blank LM, Wierckx N. Streamlined Pseudomonas taiwanensis VLB120 Chassis Strains with Improved Bioprocess Features. ACS Synth Biol 2019; 8:2036-2050. [PMID: 31465206 DOI: 10.1021/acssynbio.9b00108] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Microbes harbor many traits that are dispensable or even unfavorable under industrial and laboratory settings. The elimination of such traits could improve the host's efficiency, genetic stability, and robustness, thereby increasing the predictability and boosting its performance as a microbial cell factory. We engineered solvent-tolerant Pseudomonas taiwanensis VLB120 to yield streamlined chassis strains with higher growth rates and biomass yields, enhanced solvent tolerance, and improved process performance. In total, the genome was reduced by up to 10%. This was achieved by the elimination of genes that enable the cell to swim and form biofilms and by the deletion of the megaplasmid pSTY and large proviral segments. The resulting strain GRC1 had a 15% higher growth rate and biomass yield than the wildtype. However, this strain lacks the pSTY-encoded efflux pump TtgGHI, rendering it solvent-sensitive. Through reintegration of ttgGHI by chromosomal insertion without (GRC2) and with (GRC3) the corresponding regulator genes, the solvent-tolerant phenotype was enhanced. The generated P. taiwanensis GRC strains enlarge the repertoire of streamlined chassis with enhanced key performance indicators, making them attractive hosts for biotechnological applications. The different solvent tolerance levels of GRC1, GRC2, and GRC3 enable the selection of a fitting host platform in relation to the desired process requirements in a chassis à la carte principle. This was demonstrated in a metabolic engineering approach for the production of phenol from glycerol. The streamlined producer GRC1Δ5-TPL38 outperformed the equivalent nonstreamlined producer VLB120Δ5-TPL38 concerning phenol titer, rate, and yield, thereby highlighting the added value of the streamlined chassis.
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Affiliation(s)
- Benedikt Wynands
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Maike Otto
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Nadine Runge
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Sarah Preckel
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Tino Polen
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Lars M. Blank
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Nick Wierckx
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
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Halmschlag B, Steurer X, Putri SP, Fukusaki E, Blank LM. Tailor-made poly-γ-glutamic acid production. Metab Eng 2019; 55:239-248. [DOI: 10.1016/j.ymben.2019.07.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 07/16/2019] [Accepted: 07/20/2019] [Indexed: 10/26/2022]
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Geissler M, Kühle I, Morabbi Heravi K, Altenbuchner J, Henkel M, Hausmann R. Evaluation of surfactin synthesis in a genome reduced Bacillus subtilis strain. AMB Express 2019; 9:84. [PMID: 31190306 PMCID: PMC6562014 DOI: 10.1186/s13568-019-0806-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Accepted: 06/05/2019] [Indexed: 11/10/2022] Open
Abstract
Strain engineering is often a method of choice towards increasing the yields of the biosurfactant surfactin which is naturally synthesized by many Bacillus spp., most notably Bacillus subtilis. In the current study, a genome reduced B. subtilis 168 strain lacking 10% of the genome was established and tested for its suitability to synthesize surfactin under aerobic and anaerobic conditions at 25 °C, 30 °C, 37 °C and 40 °C. This genome reduced strain was named IIG-Bs20-5-1 and lacks, amongst others, genes synthesizing the lipopeptide plipastatin, the antibiotic bacilysin, toxins and prophages, as well as genes involved in sporulation. Amongst all temperatures tested, 37 °C was overall superior. In comparison to the reference strain JABs24, a surfactin synthesizing variant of B. subtilis 168, strain IIG-Bs20-5-1 was both aerobically and anaerobically superior with respect to specific growth rates µ and yields YX/S. However, in terms of surfactin production, strain JABs24 reached higher absolute concentrations with up to 1147.03 mg/L and 296.37 mg/L under aerobic and anaerobic conditions, respectively. Concomitant, strain JABs24 reached higher YP/S and YP/X. Here, an outstanding YP/X of 1.541 g/g was obtained under anaerobic conditions at 37 °C. The current study indicates that the employed genome reduced strain IIG-Bs20-5-1 has several advantages over the strain JABs24 such as better conversion from glucose into biomass and higher growth rates. However, regarding surfactin synthesis and yields, the strain was overall inferior at the investigated temperatures and oxygen conditions. Further studies addressing process development and strain engineering should be performed combining the current observed advantages of the genome reduced strain to increase the surfactin yields and to construct a tailor-made genome reduced strain to realize the theoretically expected advantages of such genome reduced strains.
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Phosphosugar Stress in Bacillus subtilis: Intracellular Accumulation of Mannose 6-Phosphate Derepressed the glcR-phoC Operon from Repression by GlcR. J Bacteriol 2019; 201:JB.00732-18. [PMID: 30782637 DOI: 10.1128/jb.00732-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 02/14/2019] [Indexed: 01/10/2023] Open
Abstract
Bacillus subtilis phosphorylates sugars during or after their transport into the cell. Perturbation in the conversion of intracellular phosphosugars to the central carbon metabolites and accumulation of phosphosugars can impose stress on the cells. In this study, we investigated the effect of phosphosugar stress on B. subtilis Preliminary experiments indicated that the nonmetabolizable analogs of glucose were unable to impose stress on B. subtilis In contrast, deletion of manA encoding mannose 6-phosphate isomerase (responsible for conversion of mannose 6-phosphate to fructose 6-phosphate) resulted in growth arrest and bulged cell shape in the medium containing mannose. Besides, an operon encoding a repressor (GlcR) and a haloic acid dehalogenase (HAD)-like phosphatase (PhoC; previously YwpJ) were upregulated. Integration of the P glcR-lacZ cassette into different mutational backgrounds indicated that P glcR is induced when (i) a manA-deficient strain is cultured with mannose or (ii) when glcR is deleted. GlcR repressed the transcription of glcR-phoC by binding to the σA-type core elements of P glcR An electrophoretic mobility shift assay showed no interaction between mannose 6-phosphate (or other phosphosugars) and the GlcR-P glcR DNA complex. PhoC was an acid phosphatase mainly able to dephosphorylate glycerol 3-phosphate and ribose 5-phosphate. Mannose 6-phosphate was only weakly dephosphorylated by PhoC. Since deletion of glcR and phoC alone or in combination had no effect on the cells during phosphosugar stress, it is assumed that the derepression of glcR-phoC is a side effect of phosphosugar stress in B. subtilis IMPORTANCE Bacillus subtilis has different stress response systems to cope with external and internal stressors. Here, we investigated how B. subtilis deals with the high intracellular concentration of phosphosugars as an internal stressor. The results indicated the derepression of an operon consisting of a repressor (GlcR) and a phosphatase (PhoC). Further analysis revealed that this operon is not a phosphosugar stress response system. The substrate specificity of PhoC may indicate a connection between the glcR-phoC operon and pathways in which glycerol 3-phosphate and ribose 5-phosphate are utilized, such as membrane biosynthesis and teichoic acid elongation.
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Noack S, Baumgart M. Communities of Niche-Optimized Strains: Small-Genome Organism Consortia in Bioproduction. Trends Biotechnol 2019; 37:126-139. [DOI: 10.1016/j.tibtech.2018.07.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 07/16/2018] [Accepted: 07/17/2018] [Indexed: 12/30/2022]
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Cross Talk among Transporters of the Phosphoenolpyruvate-Dependent Phosphotransferase System in Bacillus subtilis. J Bacteriol 2018; 200:JB.00213-18. [PMID: 30038046 PMCID: PMC6148471 DOI: 10.1128/jb.00213-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 07/18/2018] [Indexed: 12/23/2022] Open
Abstract
The phosphoenolpyruvate-dependent phosphotransferase system (PTS) is the main carbohydrate uptake system in Bacillus subtilis A typical PTS consists of two general proteins, enzyme I (EI) and a histidine-containing protein (HPr), as well as a specific carbohydrate transporter (or enzyme II [EII]), all of which transfer the phosphoryl group from phosphoenolpyruvate to the transported carbohydrate. The specific PTS transporters are formed by multidomain proteins or single-domain subunits. These domains are domain C (EIIC), the transmembrane channel for the carbohydrate transport; domain B (EIIB), the membrane-bound domain responsible for phosphorylation of the carbohydrate; and domain A (EIIA), the mediator between HPr(H15∼P) and EIIB. There are 16 PTS transporters in B. subtilis, 6 of which, i.e., NagP, MalP, MurP, TreP, SacP, and SacX, contain no EIIA domain. Deletion of the single-EIIA-containing transporters showed that there is cross talk between the noncognate EIIA and EIIB domains in PTS. By deletion of all EIIA-containing proteins, strain KM455 (ΔEIIA) was constructed, and the EIIA-containing proteins were individually introduced into the strain. In this way, the PTS transporters of the glucose family, namely, PtsG, GamP, and PtsA (also known as YpqE), enabled growth with maltose, N-acetylglucosamine, sucrose, or trehalose as the sole carbon source. Construction of TkmA-EIIA fusion proteins confirmed the probable interaction between the EIIAs of the glucose family of PTS transporters and the EIIA-deficient PTS transporters. Likewise, we have shown that SacX is mainly phosphorylated by PtsA and GamP. PtsG and GmuA were also able to phosphorylate SacX, albeit less well than GamP and PtsA.IMPORTANCE The phosphoenolpyruvate-dependent phosphotransferase system (PTS) not only is a carbohydrate uptake system in B. subtilis but also plays an important role in sensing the nutrient fluctuation in the medium. This sensing system enables the cells to respond to these fluctuations properly. The PTS transporters have a pivotal role in this sensing system since they are carbohydrate specific. In this study, we tried to understand the interactions among these transporters which revealed the cross talk among PTSs. Three PTS proteins, namely, PtsG (the specific transporter of glucose), GamP (the specific transporter of glucosamine), and PtsA (a cytoplasmic single-domain EIIA protein) were shown to play the major role in the interaction among the PTSs.
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Schilling T, Dietrich S, Hoppert M, Hertel R. A CRISPR-Cas9-Based Toolkit for Fast and Precise In Vivo Genetic Engineering of Bacillus subtilis Phages. Viruses 2018; 10:v10050241. [PMID: 29734705 PMCID: PMC5977234 DOI: 10.3390/v10050241] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 04/29/2018] [Accepted: 05/01/2018] [Indexed: 12/13/2022] Open
Abstract
Phages are currently under discussion as a solution for the antibiotic crisis, as they may cure diseases caused by multi-drug-resistant pathogens. However, knowledge of phage biology and genetics is limited, which impedes risk assessment of therapeutic applications. In order to enable advances in phage genetic research, the aim of this work was to create a toolkit for simple and fast genetic engineering of phages recruiting Bacillus subtilis as host system. The model organism B. subtilis represents a non-pathogenic surrogate of its harmful relatives, such as Bacillus anthracis or Bacillus cereus. This toolkit comprises the application CutSPR, a bioinformatic tool for rapid primer design, and facilitates the cloning of specific CRISPR-Cas9-based mutagenesis plasmids. The employment of the prophage-free and super-competent B. subtilis TS01 strain enables an easy and fast introduction of specific constructs for in vivo phage mutagenesis. Clean gene deletions and a functional clean gene insertion into the genome of the model phage vB_BsuP-Goe1 served as proof of concept and demonstrate reliability and high efficiency. The here presented toolkit allows comprehensive investigation of the diverse phage genetic pool, a better understanding of phage biology, and safe phage applications.
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Affiliation(s)
- Tobias Schilling
- Department of Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August-University Göttingen, 37077 Göttingen, Germany.
| | - Sascha Dietrich
- Department of Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August-University Göttingen, 37077 Göttingen, Germany.
| | - Michael Hoppert
- Department of General Microbiology, Institute of Microbiology and Genetics, Georg-August-University Göttingen, 37077 Göttingen, Germany.
| | - Robert Hertel
- Department of Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August-University Göttingen, 37077 Göttingen, Germany.
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31
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Wu J, Deng A, Sun Q, Bai H, Sun Z, Shang X, Zhang Y, Liu Q, Liang Y, Liu S, Che Y, Wen T. Bacterial Genome Editing via a Designed Toxin-Antitoxin Cassette. ACS Synth Biol 2018; 7:822-831. [PMID: 28094982 DOI: 10.1021/acssynbio.6b00287] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Manipulating the bacterial genomes in an efficient manner is essential to biological and biotechnological research. Here, we reprogrammed the bacterial TA systems as the toxin counter-selectable cassette regulated by an antitoxin switch (TCCRAS) for genetic modifications in the extensively studied and utilized Gram-positive bacteria, B. subtilis and Corynebacterium glutamicum. In the five characterized type II TA systems, the RelBE complex can specifically and efficiently regulate cell growth and death by the conditionally controlled antitoxin RelB switch, thereby serving as a novel counter-selectable cassette to establish the TCCRAS system. Using a single vector, such a system has been employed to perform in-frame deletion, functional knock-in, gene replacement, precise point mutation, large-scale insertion, and especially, deletion of the fragments up to 194.9 kb in B. subtilis. In addition, the biosynthesis of lycopene was first achieved in B. subtilis using TCCRAS to integrate a 5.4-kb fusion cluster ( P spac- crtI- crtE- crtB). The system was further adapted for gene knockdown and replacement, and large-scale deletion of the fragments up to 179.8 kb in C. glutamicum, with the mutation efficiencies increased by 0.8-1.0-fold compared to the conventional SacB method. TCCRAS thus holds promise as an effective and versatile genome-scale engineering technology for metabolic engineering and synthetic genomics research in a broad range of the Gram-positive bacteria.
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Affiliation(s)
- Jie Wu
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Aihua Deng
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Qinyun Sun
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Hua Bai
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhaopeng Sun
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiuling Shang
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yun Zhang
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Qian Liu
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yong Liang
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Shuwen Liu
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yongsheng Che
- State Key Laboratory of Toxicology & Medical Countermeasures, Beijing Institute of Pharmacology & Toxicology, Beijing 100850, China
| | - Tingyi Wen
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- Savaid medical school, University of Chinese Academy of Sciences, Beijing 100049, China
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An enhanced vector-free allele exchange (VFAE) mutagenesis protocol for genome editing in a wide range of bacterial species. AMB Express 2017. [PMID: 28629206 PMCID: PMC5474227 DOI: 10.1186/s13568-017-0425-y] [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] [Indexed: 11/10/2022] Open
Abstract
Vector-free allele exchange (VFAE) is a newly developed protocol for genome editing in Pseudomonas species. Although several parameters have been determined to optimize the procedures for obtaining a stable and high-frequency mutation, numerous false-positive clones still appear on the plate, which increases the difficulty of finding the desired mutants. It has also not been established whether this protocol can be used for genome editing in other bacterial species. In the current study, the protocol was modified to dramatically decrease the occurrence of false-positive colonies using Pseudomonas stutzeri A1501 as a model strain. This improvement was reached by increasing the occurrence of circular-DNA cassettes of the correct size. Furthermore, the enhanced protocol was used to construct mutants in both the gram-negative Escherichia coli BL21 and gram-positive Bacillus subtilis 168 strains. The protocol works well in both strains, yielding ideal results with a low percentage of false-positive colonies. In summary, the enhanced VFAE mutagenesis protocol is a potential tool for use in bacterial genome editing.
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33
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Reuß DR, Commichau FM, Stülke J. The contribution of bacterial genome engineering to sustainable development. Microb Biotechnol 2017; 10:1259-1263. [PMID: 28772004 PMCID: PMC5609340 DOI: 10.1111/1751-7915.12784] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 07/01/2017] [Indexed: 11/30/2022] Open
Abstract
The United Nations’ Sustainable Development Goals define important challenges for the prosperous development of mankind. To reach several of these goals, among them the production of value‐added compounds, improved economic and ecologic balance of production processes, prevention of climate change and protection of ecosystems, the use of engineered bacteria can make valuable contributions. We discuss the strategies for genome engineering and how they can be applied to meet the United Nations’ goals for sustainable development.
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Affiliation(s)
- Daniel R Reuß
- Department of General Microbiology, Institute of Microbiology and Genetics, Georg-August University Göttingen, Grisebachstr. 8, D-37077, Göttingen, Germany
| | - Fabian M Commichau
- Department of General Microbiology, Institute of Microbiology and Genetics, Georg-August University Göttingen, Grisebachstr. 8, D-37077, Göttingen, Germany
| | - Jörg Stülke
- Department of General Microbiology, Institute of Microbiology and Genetics, Georg-August University Göttingen, Grisebachstr. 8, D-37077, Göttingen, Germany
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34
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Reuß DR, Altenbuchner J, Mäder U, Rath H, Ischebeck T, Sappa PK, Thürmer A, Guérin C, Nicolas P, Steil L, Zhu B, Feussner I, Klumpp S, Daniel R, Commichau FM, Völker U, Stülke J. Large-scale reduction of the Bacillus subtilis genome: consequences for the transcriptional network, resource allocation, and metabolism. Genome Res 2016; 27:289-299. [PMID: 27965289 PMCID: PMC5287234 DOI: 10.1101/gr.215293.116] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 12/01/2016] [Indexed: 11/24/2022]
Abstract
Understanding cellular life requires a comprehensive knowledge of the essential cellular functions, the components involved, and their interactions. Minimized genomes are an important tool to gain this knowledge. We have constructed strains of the model bacterium, Bacillus subtilis, whose genomes have been reduced by ∼36%. These strains are fully viable, and their growth rates in complex medium are comparable to those of wild type strains. An in-depth multi-omics analysis of the genome reduced strains revealed how the deletions affect the transcription regulatory network of the cell, translation resource allocation, and metabolism. A comparison of gene counts and resource allocation demonstrates drastic differences in the two parameters, with 50% of the genes using as little as 10% of translation capacity, whereas the 6% essential genes require 57% of the translation resources. Taken together, the results are a valuable resource on gene dispensability in B. subtilis, and they suggest the roads to further genome reduction to approach the final aim of a minimal cell in which all functions are understood.
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Affiliation(s)
- Daniel R Reuß
- Department of General Microbiology, Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Josef Altenbuchner
- Institute for Industrial Genetics, University of Stuttgart, 70569 Stuttgart, Germany
| | - Ulrike Mäder
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, 17487 Greifswald, Germany
| | - Hermann Rath
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, 17487 Greifswald, Germany
| | - Till Ischebeck
- Department of Plant Biochemistry, Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Praveen Kumar Sappa
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, 17487 Greifswald, Germany
| | - Andrea Thürmer
- Department of Genomic and Applied Microbiology, Göttingen Genomics Laboratory, Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Cyprien Guérin
- MaIAGE, INRA Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Pierre Nicolas
- MaIAGE, INRA Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Leif Steil
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, 17487 Greifswald, Germany
| | - Bingyao Zhu
- Department of General Microbiology, Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Ivo Feussner
- Department of Plant Biochemistry, Georg-August-University Göttingen, 37077 Göttingen, Germany.,Georg-August-University, Göttingen Center for Molecular Biosciences (GZMB), 37077 Göttingen, Germany
| | - Stefan Klumpp
- Institute for Nonlinear Dynamics, Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Rolf Daniel
- Department of Genomic and Applied Microbiology, Göttingen Genomics Laboratory, Georg-August-University Göttingen, 37077 Göttingen, Germany.,Georg-August-University, Göttingen Center for Molecular Biosciences (GZMB), 37077 Göttingen, Germany
| | - Fabian M Commichau
- Department of General Microbiology, Georg-August-University Göttingen, 37077 Göttingen, Germany.,Georg-August-University, Göttingen Center for Molecular Biosciences (GZMB), 37077 Göttingen, Germany
| | - Uwe Völker
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, 17487 Greifswald, Germany
| | - Jörg Stülke
- Department of General Microbiology, Georg-August-University Göttingen, 37077 Göttingen, Germany.,Georg-August-University, Göttingen Center for Molecular Biosciences (GZMB), 37077 Göttingen, Germany
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Abstract
Bacillus subtilis is one of the best-studied organisms. Due to the broad knowledge and annotation and the well-developed genetic system, this bacterium is an excellent starting point for genome minimization with the aim of constructing a minimal cell. We have analyzed the genome of B. subtilis and selected all genes that are required to allow life in complex medium at 37°C. This selection is based on the known information on essential genes and functions as well as on gene and protein expression data and gene conservation. The list presented here includes 523 and 119 genes coding for proteins and RNAs, respectively. These proteins and RNAs are required for the basic functions of life in information processing (replication and chromosome maintenance, transcription, translation, protein folding, and secretion), metabolism, cell division, and the integrity of the minimal cell. The completeness of the selected metabolic pathways, reactions, and enzymes was verified by the development of a model of metabolism of the minimal cell. A comparison of the MiniBacillus genome to the recently reported designed minimal genome of Mycoplasma mycoides JCVI-syn3.0 indicates excellent agreement in the information-processing pathways, whereas each species has a metabolism that reflects specific evolution and adaptation. The blueprint of MiniBacillus presented here serves as the starting point for a successive reduction of the B. subtilis genome.
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Editing of the Bacillus subtilis Genome by the CRISPR-Cas9 System. Appl Environ Microbiol 2016; 82:5421-7. [PMID: 27342565 DOI: 10.1128/aem.01453-16] [Citation(s) in RCA: 209] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 06/22/2016] [Indexed: 12/26/2022] Open
Abstract
UNLABELLED The clustered regularly interspaced short palindromic repeat (CRISPR)-associated (Cas) systems are adaptive immune systems of bacteria. A type II CRISPR-Cas9 system from Streptococcus pyogenes has recently been developed into a genome engineering tool for prokaryotes and eukaryotes. Here, we present a single-plasmid system which allows efficient genome editing of Bacillus subtilis The plasmid pJOE8999 is a shuttle vector that has a pUC minimal origin of replication for Escherichia coli, the temperature-sensitive replication origin of plasmid pE194(ts) for B. subtilis, and a kanamycin resistance gene working in both organisms. For genome editing, it carries the cas9 gene under the control of the B. subtilis mannose-inducible promoter PmanP and a single guide RNA (sgRNA)-encoding sequence transcribed via a strong promoter. This sgRNA guides the Cas9 nuclease to its target. The 20-nucleotide spacer sequence at the 5' end of the sgRNA sequence, responsible for target specificity, is located between BsaI sites. Thus, the target specificity is altered by changing the spacer sequences via oligonucleotides fitted between the BsaI sites. Cas9 in complex with the sgRNA induces double-strand breaks (DSBs) at its target site. Repair of the DSBs and the required modification of the genome are achieved by adding homology templates, usually two PCR fragments obtained from both sides of the target sequence. Two adjacent SfiI sites enable the ordered integration of these homology templates into the vector. The function of the CRISPR-Cas9 vector was demonstrated by introducing two large deletions in the B. subtilis chromosome and by repair of the trpC2 mutation of B. subtilis 168. IMPORTANCE In prokaryotes, most methods used for scarless genome engineering are based on selection-counterselection systems. The disadvantages are often the lack of a suitable counterselection marker, the toxicity of the compounds needed for counterselection, and the requirement of certain mutations in the target strain. CRISPR-Cas systems were recently developed as important tools for genome editing. The single-plasmid system constructed for the genome editing of B. subtilis overcomes the problems of counterselection methods. It allows deletions and introduction of point mutations. It is easy to handle and very efficient, and it may be adapted for use in other firmicutes.
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Complete Genome Sequence of Bacillus subtilis subsp. subtilis Strain ∆6. GENOME ANNOUNCEMENTS 2016; 4:4/4/e00759-16. [PMID: 27469946 PMCID: PMC4966479 DOI: 10.1128/genomea.00759-16] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Bacillus subtilis ∆6 is a genome-reduced strain that was cured from six prophages and AT-rich islands. This strain is of great interest for biotechnological applications. Here, we announce the full-genome sequence of this strain. Interestingly, the conjugative element ICEBs1 has most likely undergone self-excision in B. subtilis ∆6.
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Rahmer R, Morabbi Heravi K, Altenbuchner J. Construction of a Super-Competent Bacillus subtilis 168 Using the P mtlA -comKS Inducible Cassette. Front Microbiol 2015; 6:1431. [PMID: 26732353 PMCID: PMC4685060 DOI: 10.3389/fmicb.2015.01431] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 12/01/2015] [Indexed: 11/16/2022] Open
Abstract
Competence is a physiological state that enables Bacillus subtilis 168 to take up and internalize extracellular DNA. In practice, only a small subpopulation of B. subtilis 168 cells becomes competent when they enter stationary phase. In this study, we developed a new transformation method to improve the transformation efficiency of B. subtilis 168, specially in rich media. At first, different competence genes, namely comK, comS, and dprA, were alone or together integrated into the chromosome of B. subtilis 168 under control of mannitol-inducible PmtlA promoter. Overexpression of both comK and comS increased the transformation efficiency of B. subtilis REG19 with plasmid DNA by 6.7-fold compared to the wild type strain 168. This transformation efficiency reached its maximal level after 1.5 h of induction by mannitol. Besides, transformability of the REG19 cells was saturated in the presence of 100 ng dimeric plasmid or 3000 ng chromosomal DNA. Studying the influence of global regulators on the development of competence pointed out that important competence development factors, such as Spo0A, ComQXPA, and DegU, could be removed in REG19. On the other hand, efficient REG19 transformation remained highly dependent on the original copies of comK and comS regardless of the presence of PmtlA-comKS. Finally, novel plasmid-free strategies were used for transformation of REG19 based on Gibson assembly.
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Affiliation(s)
- Regine Rahmer
- Institut für Industrielle Genetik, Universität Stuttgart Stuttgart, Germany
| | | | - Josef Altenbuchner
- Institut für Industrielle Genetik, Universität Stuttgart Stuttgart, Germany
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Identification and characterization of the vanillin dehydrogenase YfmT in Bacillus subtilis 3NA. Appl Microbiol Biotechnol 2015; 100:3511-21. [DOI: 10.1007/s00253-015-7197-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 11/21/2015] [Accepted: 11/23/2015] [Indexed: 11/27/2022]
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