1
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Yue XJ, Wang JR, Zhao JN, Pan Z, Li YZ. Determination of the chromosomal position effects for plug-and-play application in the Myxococcus xanthus chassis cells. Synth Syst Biotechnol 2024; 9:540-548. [PMID: 38680947 PMCID: PMC11046052 DOI: 10.1016/j.synbio.2024.04.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 03/30/2024] [Accepted: 04/08/2024] [Indexed: 05/01/2024] Open
Abstract
The chromosomal position effect can significantly affect the transgene expression, which may provide an efficient strategy for the inauguration of alien genes in new hosts, but has been less explored rationally. The bacterium Myxococcus xanthus harbors a large circular high-GC genome, and the position effect in this chassis may result in a thousand-fold expression variation of alien natural products. In this study, we conducted transposon insertion at TA sites on the M. xanthus genome, and used enrichment and dilution indexes to respectively appraise high and low expression potentials of alien genes at insertion sites. The enrichment sites are characteristically distributed along the genome, and the dilution sites are overlapped well with the horizontal transfer genes. We experimentally demonstrated the enrichment sites as high expression integration sites (HEISs), and the dilution sites unsuitable for gene integration expression. This work highlights that HEISs are the plug-and-play sites for efficient expression of integrated genes.
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Affiliation(s)
- Xin-jing Yue
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, PR China
| | - Jia-rui Wang
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, PR China
| | - Jun-ning Zhao
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, PR China
| | - Zhuo Pan
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, PR China
| | - Yue-zhong Li
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, PR China
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2
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Ye B, Tao Q, Yan X. A transposon system for random insertion of a gene expression cassette into the chromosome of Bacillus subtilis. J Biotechnol 2023; 361:66-73. [PMID: 36494011 DOI: 10.1016/j.jbiotec.2022.11.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 11/30/2022] [Indexed: 12/12/2022]
Abstract
Bacillus subtilis is a robust industrial workhorse for the production of heterologous proteins. Chromosomal integration-based protein production has advantages over plasmid-based methods. Considering that the expression level of a gene is affected by its location in the chromosome, it is important to find an optimal integration site for the gene to be expressed. This work establishes a method for random insertion of a gene expression cassette into chromosomes, enabling the screening of optimal integration sites for high-level protein production. Specifically, a gene expression cassette and a chloromycetin-resistance marker are assembled into a transposon. This transposon is inserted between the promoter and the ribosomal binding site of the zeocin-resistance marker in the chromosome, which blocks the transcription of the zeocin-resistance gene. Transposase Himar1-mediated transposition of this transposon activates the zeocin-resistance marker, which can be selected on plates containing both chloromycetin and zeocin. The transposition frequency was over 10-5. This method was used to select proper insertion sites for the expression cassette of methyl parathion hydrolase (MPH). Compared with the common integration site amyE, the expression level of MPH was increased up to 50 % at the yjbH site.
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Affiliation(s)
- Bin Ye
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, PR China; Institute of Microbe and Host Health, College of Agriculture and Forestry, Linyi University, Linyi, Shandong 276000, PR China
| | - Qing Tao
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, PR China
| | - Xin Yan
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, PR China.
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3
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Scholz SA, Lindeboom CD, Freddolino PL. Genetic context effects can override canonical cis regulatory elements in Escherichia coli. Nucleic Acids Res 2022; 50:10360-10375. [PMID: 36134716 PMCID: PMC9561378 DOI: 10.1093/nar/gkac787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 08/10/2022] [Accepted: 09/02/2022] [Indexed: 11/12/2022] Open
Abstract
Recent experiments have shown that in addition to control by cis regulatory elements, the local chromosomal context of a gene also has a profound impact on its transcription. Although this chromosome-position dependent expression variation has been empirically mapped at high-resolution, the underlying causes of the variation have not been elucidated. Here, we demonstrate that 1 kb of flanking, non-coding synthetic sequences with a low frequency of guanosine and cytosine (GC) can dramatically reduce reporter expression compared to neutral and high GC-content flanks in Escherichia coli. Natural and artificial genetic context can have a similarly strong effect on reporter expression, regardless of cell growth phase or medium. Despite the strong reduction in the maximal expression level from the fully-induced reporter, low GC synthetic flanks do not affect the time required to reach the maximal expression level after induction. Overall, we demonstrate key determinants of transcriptional propensity that appear to act as tunable modulators of transcription, independent of regulatory sequences such as the promoter. These findings provide insight into the regulation of naturally occurring genes and an independent control for optimizing expression of synthetic biology constructs.
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Affiliation(s)
- Scott A Scholz
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Chase D Lindeboom
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Peter L Freddolino
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, USA
- Department of Computational Medicine and Bioinformatics, University of Michigan Medical School, Ann Arbor, MI, USA
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4
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Jeong DE, Kim MS, Kim HR, Choi SK. Cell Factory Engineering of Undomesticated Bacillus Strains Using a Modified Integrative and Conjugative Element for Efficient Plasmid Delivery. Front Microbiol 2022; 13:802040. [PMID: 35558120 PMCID: PMC9086855 DOI: 10.3389/fmicb.2022.802040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 01/14/2022] [Indexed: 11/29/2022] Open
Abstract
A large number of Bacillus strains have been isolated from various environments and many of them have great potential as cell factories. However, they have been rarely developed as cell factories due to their poor transformation efficiency. In this study, we developed a highly efficient plasmid delivery system for undomesticated Bacillus strains using a modified integrative and conjugative element (MICE), which was designed to be activated by an inducer, prevent self-transfer, and deliver desired plasmids to the recipient cells. The MICE system was demonstrated to successfully introduce a gfp-containing plasmid into all 41 undomesticated Bacillus subtilis strains tested and eight other Bacillus species. The MICE was used to deliver a cytosine base editor (CBE)-based multiplex genome-editing tool for the cell factory engineering of the Bacillus species. The introduced CBE enabled one-step inactivation of the major extracellular protease genes of the tested strains. The engineered strains were used as hosts for heterologous expression of nattokinase, which resulted in various enzyme expression levels. The results suggested that the MICE and CBE systems can be powerful tools for genetic engineering of undomesticated Bacillus strains, and greatly contribute to the expansion of the Bacillus cell factory.
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Affiliation(s)
- Da-Eun Jeong
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea
| | - Man Su Kim
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea.,Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology (UST), Daejeon, South Korea
| | - Ha-Rim Kim
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea
| | - Soo-Keun Choi
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea.,Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology (UST), Daejeon, South Korea
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5
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Luo J, Cheng X, Su Y, Zhang L, Du W, Bao X, Huang W, Feng Q, Cao J, Wu Y. Metagenomic assembly deciphered the type-dependent effects of surfactants on the fates of antibiotics resistance genes during sludge fermentation and the underlying mechanisms. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 807:150822. [PMID: 34627892 DOI: 10.1016/j.scitotenv.2021.150822] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 09/29/2021] [Accepted: 10/01/2021] [Indexed: 06/13/2023]
Abstract
Waste activated sludge (WAS) is an important reservoir of antibiotic resistance genes (ARGs). However, the interactive effects of co-existed substances in WAS on ARGs fates have yet to be disclosed. This study demonstrated the type-dependent effects of surfactants (potentially effective chemicals for WAS disposal) on the reduction of ARGs during WAS fermentation, which followed the order of linear alkylbenzene sulphonates (LAS) > alkyl polyglucoside (APG) > hexadecyl trimethyl ammonium bromide (HTAB). Interestingly, the ratio of ARGs affiliated to efflux pump showed an upward trend in the surfactant-treated reactor. Mechanistic investigations revealed that the extracellular polymeric substances (EPS) destruction induced by surfactants increased the permeability of bacterial cells and caused the ARGs being released and susceptible for subsequent elimination. Besides, the surfactants significantly altered the microbial community, resulting in the ARGs reduction via changing the potential hosts. Also, the metabolic pathways participated in the dissemination of ARGs were remarkably down-regulated, thereby resulting in the reduction of ARGs abundances. This work broadened the understanding of ARGs fates during WAS fermentation and provided insights on the interactive functions of exogenous chemicals in multiple matrics.
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Affiliation(s)
- Jingyang Luo
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, PR China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, PR China
| | - Xiaoshi Cheng
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, PR China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, PR China
| | - Yinglong Su
- Shanghai Engineering Research Center of Biotransformation on Organic Solid Waste, School of Ecological and Environmental Sciences, East China University, Shanghai 200241, China
| | - Le Zhang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, PR China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, PR China
| | - Wei Du
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, PR China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, PR China
| | - Xingchen Bao
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, PR China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, PR China
| | - Wenxuan Huang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, PR China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, PR China
| | - Qian Feng
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, PR China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, PR China
| | - Jiashun Cao
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, PR China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, PR China
| | - Yang Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China.
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6
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Zhou C, Yang G, Zhang L, Zhang H, Zhou H, Lu F. Construction of an alkaline protease overproducer strain based on Bacillus licheniformis 2709 using an integrative approach. Int J Biol Macromol 2021; 193:1449-1456. [PMID: 34742839 DOI: 10.1016/j.ijbiomac.2021.10.208] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 10/27/2021] [Accepted: 10/27/2021] [Indexed: 11/16/2022]
Abstract
Bacillus licheniformis 2709 is a potential cell factory for the production of alkaline protease AprE, which has important value in industrial application but still lacks sufficient production capacity. To address this problem, we investigated the effects of the secretory viscous materials on the synthesis of AprE, which might seriously affect the industrial fermentation. Furthermore, an iterative chromosomal integration strategy at various chromosomal loci was implemented to achieve stable high-level expression of AprE in B. licheniformis 2709. The host was genetically modified by disrupting the native pgs cluster controlling the biosynthesis of viscous poly-glutamic acid identified in the study by GC/MS, generating a mutant with significantly higher biomass and better bioreactor performance. We further enhanced the expression of alkaline protease by integrating two additional aprE expression cassettes into the genome, generating the integration mutant BL ∆UEP-3 with three aprE expression cassettes, whose AprE enzyme activity in shake flasks reached 25,736 ± 997 U/mL, which was 136% higher than that of the original strain, while the aprE transcription level increased 4.05 times. Thus, an AprE high-yielding strain with excellent fermentation traits was engineered, which was more suitable for bulk-production. Finally, the AprE titer was further increased in a 5-L fermenter, reaching 57,763 ± 1039 U/mL. In summary, genetic modification is an enabling technology for enhancing enzyme production by eliminating the unfavorable characteristics of the host and optimizing the expression of aprE through iterative chromosomal integration. We believe that the protocol developed in this study provides a valuable reference for chromosomal overexpression of proteins or bioactive molecules in other Bacillus species.
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Affiliation(s)
- Cuixia Zhou
- School of Biology and Brewing Engineering, Taishan University, Taian 271018, PR China; Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science &Technology, Tianjin 300450, PR China
| | - Guangcheng Yang
- School of Biology and Brewing Engineering, Taishan University, Taian 271018, PR China.
| | - Lei Zhang
- School of Biology and Brewing Engineering, Taishan University, Taian 271018, PR China
| | - Huitu Zhang
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science &Technology, Tianjin 300450, PR China
| | - Huiying Zhou
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science &Technology, Tianjin 300450, PR China
| | - Fuping Lu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science &Technology, Tianjin 300450, PR China.
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7
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Kim MS, Kim HR, Jeong DE, Choi SK. Cytosine Base Editor-Mediated Multiplex Genome Editing to Accelerate Discovery of Novel Antibiotics in Bacillus subtilis and Paenibacillus polymyxa. Front Microbiol 2021; 12:691839. [PMID: 34122396 PMCID: PMC8193733 DOI: 10.3389/fmicb.2021.691839] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 04/30/2021] [Indexed: 12/30/2022] Open
Abstract
Genome-based identification of new antibiotics is emerging as an alternative to traditional methods. However, uncovering hidden antibiotics under the background of known antibiotics remains a challenge. To over this problem using a quick and effective genetic approach, we developed a multiplex genome editing system using a cytosine base editor (CBE). The CBE system achieved simultaneous double, triple, quadruple, and quintuple gene editing with efficiencies of 100, 100, 83, and 75%, respectively, as well as the 100% editing efficiency of single targets in Bacillus subtilis. Whole-genome sequencing of the edited strains showed that they had an average of 8.5 off-target single-nucleotide variants at gRNA-independent positions. The CBE system was used to simultaneously knockout five known antibiotic biosynthetic gene clusters to leave only an uncharacterized polyketide biosynthetic gene cluster in Paenibacillus polymyxa E681. The polyketide showed antimicrobial activities against gram-positive bacteria, but not gram-negative bacteria and fungi. Therefore, our findings suggested that the CBE system might serve as a powerful tool for multiplex genome editing and greatly accelerating the unraveling of hidden antibiotics in Bacillus and Paenibacillus species.
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Affiliation(s)
- Man Su Kim
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea.,Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology (UST), Daejeon, South Korea
| | - Ha-Rim Kim
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea
| | - Da-Eun Jeong
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea
| | - Soo-Keun Choi
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea.,Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology (UST), Daejeon, South Korea
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8
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Nguyen KN, Kim Y, Maibunkaew S, Park J, Nguyen MT, Oh DB, Kwon O. Enhanced Production of 1-Deoxynojirimycin in Bacillus subtilis subsp. inaquosorum by Random Mutagenesis and Culture Optimization. BIOTECHNOL BIOPROC E 2021. [DOI: 10.1007/s12257-020-0231-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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9
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Su Y, Liu C, Fang H, Zhang D. Bacillus subtilis: a universal cell factory for industry, agriculture, biomaterials and medicine. Microb Cell Fact 2020; 19:173. [PMID: 32883293 PMCID: PMC7650271 DOI: 10.1186/s12934-020-01436-8] [Citation(s) in RCA: 138] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 08/27/2020] [Indexed: 12/18/2022] Open
Abstract
Due to its clear inherited backgrounds as well as simple and diverse genetic manipulation systems, Bacillus subtilis is the key Gram-positive model bacterium for studies on physiology and metabolism. Furthermore, due to its highly efficient protein secretion system and adaptable metabolism, it has been widely used as a cell factory for microbial production of chemicals, enzymes, and antimicrobial materials for industry, agriculture, and medicine. In this mini-review, we first summarize the basic genetic manipulation tools and expression systems for this bacterium, including traditional methods and novel engineering systems. Secondly, we briefly introduce its applications in the production of chemicals and enzymes, and summarize its advantages, mainly focusing on some noteworthy products and recent progress in the engineering of B. subtilis. Finally, this review also covers applications such as microbial additives and antimicrobials, as well as biofilm systems and spore formation. We hope to provide an overview for novice researchers in this area, offering them a better understanding of B. subtilis and its applications.
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Affiliation(s)
- Yuan Su
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China.,Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Chuan Liu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Huan Fang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Dawei Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China. .,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
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10
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Oh Y, Kim JA, Kim CH, Choi SK, Pan JG. Bacillus subtilis spore vaccines displaying protective antigen induce functional antibodies and protective potency. BMC Vet Res 2020; 16:259. [PMID: 32723323 PMCID: PMC7385935 DOI: 10.1186/s12917-020-02468-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 07/10/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Bacillus anthracis is the causative agent of anthrax, a disease of both humans and various animal species, and can be used as a bioterror agent. Effective vaccines are available, but those could benefit from improvements, including increasing the immunity duration, reducing the shot frequency and adverse reactions. In addition, more sophisticated antigen delivery and potentiation systems are urgently required. The protective antigen (PA), one of three major virulence factors associated with anthrax was displayed on the surface of Bacillus subtilis spores, which is a vaccine production host and delivery vector with several advantages such as a low production cost, straightforward administration as it is safe for human consumption and the particulate adjuvanticity. Mice were immunized orally (PO), intranasally (IN), sublingually (SL) or intraperitoneally (IP) with the PA displaying probiotic spore vaccine. Clinical observation, serological analysis and challenge experiment were conducted to investigate the safety and efficacy of the vaccine. RESULTS A/J mice immunized with the PA spore vaccine via PO, IN, SL, and IP were observed to have increased levels of active antibody titer, isotype profiles and toxin neutralizing antibody in sera, and IgA in saliva. The immunized mice were demonstrated to raise protective immunity against the challenge with lethal B. anthracis spores. CONCLUSIONS In this study, we developed a B. subtilis spore vaccine that displays the PA on its surface and showed that the PA-displaying spore vaccine was able to confer active immunity to a murine model based on the results of antibody isotype titration, mucosal antibody identification, and a lethal challenge experiment.
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Affiliation(s)
- Yeonsu Oh
- Department of Veterinary Pathology, College of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University, 1 Kangwondaehak-gil, Chuncheon, 24341 Republic of Korea
| | - Jung Ae Kim
- Infectious Disease Research Center (Superbacteria Group), Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Chang-Hwan Kim
- The 4th R&D Institute, Agency for Defense Development (ADD), Yuseong, Daejeon, 34186 Republic of Korea
| | - Soo-Keun Choi
- Infectious Disease Research Center (Superbacteria Group), Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Jae-Gu Pan
- Infectious Disease Research Center (Superbacteria Group), Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
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11
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Zhou C, Zhou H, Li D, Zhang H, Wang H, Lu F. Optimized expression and enhanced production of alkaline protease by genetically modified Bacillus licheniformis 2709. Microb Cell Fact 2020; 19:45. [PMID: 32093734 PMCID: PMC7041084 DOI: 10.1186/s12934-020-01307-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 02/12/2020] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Bacillus licheniformis 2709 is extensively applied as a host for the high-level production of heterologous proteins, but Bacillus cells often possess unfavorable wild-type properties, such as production of viscous materials and foam during fermentation, which seriously influenced the application in industrial fermentation. How to develop it from a soil bacterium to a super-secreting cell factory harboring less undomesticated properties always plays vital role in industrial production. Besides, the optimal expression pattern of the inducible enzymes like alkaline protease has not been optimized by comparing the transcriptional efficiency of different plasmids and genomic integration sites in B. licheniformis. RESULT Bacillus licheniformis 2709 was genetically modified by disrupting the native lchAC genes related to foaming and the eps cluster encoding the extracellular mucopolysaccharide via a markerless genome-editing method. We further optimized the expression of the alkaline protease gene (aprE) by screening the most efficient expression system among different modular plasmids and genomic loci. The results indicated that genomic expression of aprE was superior to plasmid expression and finally the transcriptional level of aprE greatly increased 1.67-fold through host optimization and chromosomal integration in the vicinity of the origin of replication, while the enzyme activity significantly improved 62.19% compared with the wild-type alkaline protease-producing strain B. licheniformis. CONCLUSION We successfully engineered an AprE high-yielding strain free of undesirable properties and its fermentation traits could be applied to bulk-production by host genetic modification and expression optimization. In summary, host optimization is an enabling technology for improving enzyme production by eliminating the harmful traits of the host and optimizing expression patterns. We believe that these strategies can be applied to improve heterologous protein expression in other Bacillus species.
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Affiliation(s)
- Cuixia Zhou
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science & Technology, No. 29, 13th Road, Tianjin Economic-Technological Development Area, Tianjin 022, 300457, People's Republic of China
| | - Huiying Zhou
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science & Technology, No. 29, 13th Road, Tianjin Economic-Technological Development Area, Tianjin 022, 300457, People's Republic of China
| | - Dengke Li
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science & Technology, No. 29, 13th Road, Tianjin Economic-Technological Development Area, Tianjin 022, 300457, People's Republic of China
| | - Huitu Zhang
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science & Technology, No. 29, 13th Road, Tianjin Economic-Technological Development Area, Tianjin 022, 300457, People's Republic of China.
| | - Hongbin Wang
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science & Technology, No. 29, 13th Road, Tianjin Economic-Technological Development Area, Tianjin 022, 300457, People's Republic of China
| | - Fuping Lu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science & Technology, No. 29, 13th Road, Tianjin Economic-Technological Development Area, Tianjin 022, 300457, People's Republic of China.
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12
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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: 13] [Impact Index Per Article: 2.6] [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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Lim H, Choi SK. Programmed gRNA Removal System for CRISPR-Cas9-Mediated Multi-Round Genome Editing in Bacillus subtilis. Front Microbiol 2019; 10:1140. [PMID: 31164882 PMCID: PMC6536666 DOI: 10.3389/fmicb.2019.01140] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 05/06/2019] [Indexed: 01/25/2023] Open
Abstract
CRISPR/Cas9 has become a simple and powerful genome editing tool for many organisms. However, multi-round genome editing should replace single-guide RNA (sgRNA) every round, which is laborious and time-consuming. Here, we have developed a multi-round genome editing system in which genome editing and the programmed removal of the sgRNA have sequentially occurred in a growth-dependent manner in Bacillus subtilis. The system contains two plasmids, one containing a cas9 gene and the other containing two sgRNAs and a donor DNA for homology directed repair (HDR). The two sgRNAs are chromosome-targeting (sgRNAct) and self-targeting (sgRNAst) under the control of a constitutive promoter and sporulation-specific promoter, respectively. In the growth phase, the sgRNAct is transcribed and complexed with the Cas9 to edit the chromosomal target, while the sgRNAst is transcribed in the sporulation phase and complexed with the Cas9 to attack its own plasmid. Therefore, the system automatically makes the cell ready for next-round genome editing during cultivation. The system was approved through the sequential deletion of eight extracellular protease genes in the B. subtilis, suggesting that it can be used for versatile applications in multi-round genome editing.
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Affiliation(s)
- Hayeon Lim
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea.,Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, Korea University of Science and Technology, Daejeon, South Korea
| | - Soo-Keun Choi
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea.,Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, Korea University of Science and Technology, Daejeon, South Korea
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Zhang W, Yang Y, Liu X, Liu C, Bai Z. Development of a secretory expression system with high compatibility between expression elements and an optimized host for endoxylanase production in Corynebacterium glutamicum. Microb Cell Fact 2019; 18:72. [PMID: 30995928 PMCID: PMC6471998 DOI: 10.1186/s12934-019-1116-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 04/03/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND In terms of protein production, the internal environment of the host influences the activity of expression elements, thus affecting the expression level of the target protein. Native expression elements from a specific strain always function well in the original host. In the present study, to enhance the endoxylanase (XynA) production level in Corynebacterium glutamicum CGMCC1.15647 with its native expression elements, approaches to reduce host expression obstacles and to promote expression were evaluated. RESULTS We identified the signal peptide of CspB2 in C. glutamicum CGMCC1.15647 by MALDI-TOF and applied it along with its promoter for the production of endoxylanase (XynA) in this strain. The native cspB2 promoter and cspB2 signal peptide are superior to the well-used cspB1 promoter and cspA signal peptide for XynA expression in C. glutamicum CGMCC1.15647, and expression in this strain is superior to the expression in C. glutamicum ATCC13032. The highest XynA secretion efficiency level in deep 24-well plates level (2492.88 U/mL) was achieved by disruption of the cell wall protein CspB2 and the protease ClpS, chromosomal integration of xynA and coexisting plasmid expression, which increased expression 11.43- and 1.35-fold compared to that of chromosomal expression and pXMJ19-xynA-mediated expression in the original strain, respectively. In fed-batch cultivation, the highest XynA accumulation (1.77 g/L) was achieved in the culture supernatant after 44 h of cultivation. CONCLUSION Adaptation between the expression elements and the host is crucial for XynA production in C. glutamicum CGMCC1.15647. Strategies including host optimization, chromosomal integration, and coexistence of plasmids were useful for efficient protein production in C. glutamicum.
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Affiliation(s)
- Wei Zhang
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, 214122 China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122 China
| | - Yankun Yang
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, 214122 China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122 China
| | - Xiuxia Liu
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, 214122 China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122 China
| | - Chunli Liu
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, 214122 China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122 China
| | - Zhonghu Bai
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, 214122 China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122 China
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Scholz SA, Diao R, Wolfe MB, Fivenson EM, Lin XN, Freddolino PL. High-Resolution Mapping of the Escherichia coli Chromosome Reveals Positions of High and Low Transcription. Cell Syst 2019; 8:212-225.e9. [PMID: 30904377 DOI: 10.1016/j.cels.2019.02.004] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 11/19/2018] [Accepted: 02/11/2019] [Indexed: 01/28/2023]
Abstract
Recent studies on targeted gene integrations in bacteria have demonstrated that chromosomal location can substantially affect a gene's expression level. However, these studies have only provided information on a small number of sites. To measure position effects on transcriptional propensity at high resolution across the genome, we built and analyzed a library of over 144,000 genome-integrated, standardized reporters in a single mixed population of Escherichia coli. We observed more than 20-fold variations in transcriptional propensity across the genome when the length of the chromosome was binned into broad 4 kbp regions; greater variability was observed over smaller regions. Our data reveal peaks of high transcriptional propensity centered on ribosomal RNA operons and core metabolic genes, while prophages and mobile genetic elements were enriched in less transcribable regions. In total, our work supports the hypothesis that E. coli has evolved gene-independent mechanisms for regulating expression from specific regions of its genome.
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Affiliation(s)
- Scott A Scholz
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI 48103, USA
| | - Rucheng Diao
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48103, USA
| | - Michael B Wolfe
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48103, USA; Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48103, USA
| | - Elayne M Fivenson
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48103, USA
| | - Xiaoxia Nina Lin
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48103, USA; Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48103, USA.
| | - Peter L Freddolino
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48103, USA; Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48103, USA.
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