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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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Sachla AJ, Alfonso AJ, Helmann JD. A Simplified Method for CRISPR-Cas9 Engineering of Bacillus subtilis. Microbiol Spectr 2021; 9:e0075421. [PMID: 34523974 PMCID: PMC8557940 DOI: 10.1128/spectrum.00754-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 08/16/2021] [Indexed: 11/20/2022] Open
Abstract
The clustered regularly interspaced short palindromic repeat (CRISPR)-Cas9 system from Streptococcus pyogenes has been widely deployed as a tool for bacterial strain construction. Conventional CRISPR-Cas9 editing strategies require design and molecular cloning of an appropriate guide RNA (gRNA) to target genome cleavage and a repair template for introduction of the desired site-specific genome modification. Here, we present a streamlined method that leverages the existing collection of nearly 4,000 Bacillus subtilis strains (the BKE collection) with individual genes replaced by an integrated erythromycin (erm) resistance cassette. A single plasmid (pAJS23) with a gRNA targeted to erm allows cleavage of the genome at any nonessential gene and at sites nearby to many essential genes. This plasmid can be engineered to include a repair template, or the repair template can be cotransformed with the plasmid as either a PCR product or genomic DNA. We demonstrate the utility of this system for generating gene replacements, site-specific mutations, modification of intergenic regions, and introduction of gene-reporter fusions. In sum, this strategy bypasses the need for gRNA design and allows the facile transfer of mutations and genetic constructions with no requirement for intermediate cloning steps. IMPORTANCE Bacillus subtilis is a well-characterized Gram-positive model organism and a popular platform for biotechnology. Although many different CRISPR-based genome editing strategies have been developed for B. subtilis, they generally involve the design and cloning of a specific guide RNA (gRNA) and repair template for each application. By targeting the erm resistance cassette with an anti-erm gRNA, genome editing can be directed to any of nearly 4,000 gene disruptants within the existing BKE collection of strains. Repair templates can be engineered as PCR products, or specific alleles and constructions can be transformed as chromosomal DNA, thereby bypassing the need for plasmid construction. The described method is rapid and facilitates a wide range of genome manipulations.
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Affiliation(s)
- Ankita J. Sachla
- Department of Microbiology, Cornell University, Ithaca, New York, USA
| | | | - John D. Helmann
- Department of Microbiology, Cornell University, Ithaca, New York, USA
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Wannier TM, Ciaccia PN, Ellington AD, Filsinger GT, Isaacs FJ, Javanmardi K, Jones MA, Kunjapur AM, Nyerges A, Pal C, Schubert MG, Church GM. Recombineering and MAGE. NATURE REVIEWS. METHODS PRIMERS 2021; 1:7. [PMID: 35540496 PMCID: PMC9083505 DOI: 10.1038/s43586-020-00006-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/19/2020] [Indexed: 12/17/2022]
Abstract
Recombination-mediated genetic engineering, also known as recombineering, is the genomic incorporation of homologous single-stranded or double-stranded DNA into bacterial genomes. Recombineering and its derivative methods have radically improved genome engineering capabilities, perhaps none more so than multiplex automated genome engineering (MAGE). MAGE is representative of a set of highly multiplexed single-stranded DNA-mediated technologies. First described in Escherichia coli, both MAGE and recombineering are being rapidly translated into diverse prokaryotes and even into eukaryotic cells. Together, this modern set of tools offers the promise of radically improving the scope and throughput of experimental biology by providing powerful new methods to ease the genetic manipulation of model and non-model organisms. In this Primer, we describe recombineering and MAGE, their optimal use, their diverse applications and methods for pairing them with other genetic editing tools. We then look forward to the future of genetic engineering.
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Affiliation(s)
- Timothy M. Wannier
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
| | - Peter N. Ciaccia
- Department of Molecular, Cellular & Developmental Biology, Yale University, New Haven, CT, USA
- Systems Biology Institute, Yale University, West Haven, CT, USA
| | - Andrew D. Ellington
- Department of Molecular Biosciences, College of Natural Sciences, University of Texas at Austin, Austin, TX, USA
| | - Gabriel T. Filsinger
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
- Department of Systems Biology, Harvard University, Cambridge, MA, USA
| | - Farren J. Isaacs
- Department of Molecular, Cellular & Developmental Biology, Yale University, New Haven, CT, USA
- Systems Biology Institute, Yale University, West Haven, CT, USA
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - Kamyab Javanmardi
- Department of Molecular Biosciences, College of Natural Sciences, University of Texas at Austin, Austin, TX, USA
| | - Michaela A. Jones
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE, USA
| | - Aditya M. Kunjapur
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE, USA
| | - Akos Nyerges
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
| | - Csaba Pal
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
| | - Max G. Schubert
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
| | - George M. Church
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
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Zhou C, Ye B, Cheng S, Zhao L, Liu Y, Jiang J, Yan X. Promoter engineering enables overproduction of foreign proteins from a single copy expression cassette in Bacillus subtilis. Microb Cell Fact 2019; 18:111. [PMID: 31200722 PMCID: PMC6570832 DOI: 10.1186/s12934-019-1159-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Accepted: 06/09/2019] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Bacillus subtilis is developed to be an attractive expression host to produce both secreted and cytoplasmic proteins owing to its prominent biological characteristics. Chromosomal integration is a stable expression strategy while the expression level is not ideal compared with plasmid expression. Thus, to meet the requirement of protein overexpression, promoter, as one of the key elements, is important. It is necessary to obtain an ideal promoter for overproduction of foreign proteins from a single copy expression cassette. RESULTS The activity of promoter Pylb was further enhanced by optimizing the - 35, - 10 core region and upstream sequence (UP) by substituting both sequences with consensus sequences. The final engineered promoter exhibited almost 26-fold in β-galactosidase (BgaB) activity and 195-fold in super-folded green fluorescent protein (sfGFP) intensity than that of WT. The two proteins account for 43% and 30% of intracellular proteins, respectively. The promoter was eventually tested by successful extracellular overproduction of Methyl Parathion Hydrolase (MPH) and Chlorothalonil hydrolytic dehalogenase (Chd) to a level of 0.3 g/L (144 U/mL) and 0.27 g/L (4.4 U/mL) on shake-flask culture condition. CONCLUSIONS A strong promoter was engineered for efficient chromosomally integrated expression of heterologous proteins.
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Affiliation(s)
- Chaoyang Zhou
- Department of Microbiology, College of Life Sciences, Key Laboratory for Microbiological Engineering of Agricultural, Environment of Ministry of Agriculture, Nanjing Agricultural University, 6 Tongwei Road, Nanjing, 210095, Jiangsu, People's Republic of China
| | - Bin Ye
- Department of Microbiology, College of Life Sciences, Key Laboratory for Microbiological Engineering of Agricultural, Environment of Ministry of Agriculture, Nanjing Agricultural University, 6 Tongwei Road, Nanjing, 210095, Jiangsu, People's Republic of China
| | - Shan Cheng
- Department of Microbiology, College of Life Sciences, Key Laboratory for Microbiological Engineering of Agricultural, Environment of Ministry of Agriculture, Nanjing Agricultural University, 6 Tongwei Road, Nanjing, 210095, Jiangsu, People's Republic of China
| | - Leizhen Zhao
- Department of Microbiology, College of Life Sciences, Key Laboratory for Microbiological Engineering of Agricultural, Environment of Ministry of Agriculture, Nanjing Agricultural University, 6 Tongwei Road, Nanjing, 210095, Jiangsu, People's Republic of China
| | - Yuanxin Liu
- Department of Microbiology, College of Life Sciences, Key Laboratory for Microbiological Engineering of Agricultural, Environment of Ministry of Agriculture, Nanjing Agricultural University, 6 Tongwei Road, Nanjing, 210095, Jiangsu, People's Republic of China
| | - Jiandong Jiang
- Department of Microbiology, College of Life Sciences, Key Laboratory for Microbiological Engineering of Agricultural, Environment of Ministry of Agriculture, Nanjing Agricultural University, 6 Tongwei Road, Nanjing, 210095, Jiangsu, People's Republic of China
| | - Xin Yan
- Department of Microbiology, College of Life Sciences, Key Laboratory for Microbiological Engineering of Agricultural, Environment of Ministry of Agriculture, Nanjing Agricultural University, 6 Tongwei Road, Nanjing, 210095, Jiangsu, People's Republic of China.
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Zhao L, Ye B, Zhang Q, Cheng D, Zhou C, Cheng S, Yan X. Construction of second generation protease-deficient hosts of Bacillus subtilis for secretion of foreign proteins. Biotechnol Bioeng 2019; 116:2052-2060. [PMID: 30989640 DOI: 10.1002/bit.26992] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 03/18/2019] [Accepted: 04/11/2019] [Indexed: 12/23/2022]
Abstract
Although one of the major factors limiting the application of Bacillus subtilis as an expression host has been its production of at least eight extracellular proteases, researchers have also noticed that some proteases benefited the secretion of foreign proteins at times. Therefore, to maximize the yield of a foreign protein, the proteases should be selectively inactivated. This raises a new question that how to identify the favorable and unfavorable proteases for a target protein. Here, an evaluation system containing nine mutant strains of B. subtilis 168 was developed to address this question. The mutant strain PD8 has all the eight proteases inactivated whereas each of the other eight mutant strains expresses only one kind of these eight proteases. The target protein is secreted in these nine mutant strains; if the production of target protein in a mutant strain is higher than that in strain PD8, the corresponding protease is regarded as favorable. Accordingly, the optimal protease-deficient host is constructed through inactivating the unfavorable proteases. The effectiveness of this system was confirmed by expressing three foreign proteins. This study provides a strategy for improving the secretion of a foreign protein in B. subtilis through tailoring a personalized protease-deficient host.
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Affiliation(s)
- Leizhen Zhao
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Bin Ye
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Qi Zhang
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Dan Cheng
- Laboratory Center of Life Sciences, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Chaoyang Zhou
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Shan Cheng
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Xin Yan
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China.,Provincial Key Laboratory of Agrobiology, Institute of Agro-biotechnology, Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu, People's Republic of China
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