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Senger J, Seitl I, Pross E, Fischer L. Secretion of the cytoplasmic and high molecular weight β-galactosidase of Paenibacillus wynnii with Bacillus subtilis. Microb Cell Fact 2024; 23:170. [PMID: 38867249 PMCID: PMC11167759 DOI: 10.1186/s12934-024-02445-7] [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: 01/18/2024] [Accepted: 05/30/2024] [Indexed: 06/14/2024] Open
Abstract
BACKGROUND The gram-positive bacterium Bacillus subtilis is widely used for industrial enzyme production. Its ability to secrete a wide range of enzymes into the extracellular medium especially facilitates downstream processing since cell disruption is avoided. Although various heterologous enzymes have been successfully secreted with B. subtilis, the secretion of cytoplasmic enzymes with high molecular weight is challenging. Only a few studies report on the secretion of cytoplasmic enzymes with a molecular weight > 100 kDa. RESULTS In this study, the cytoplasmic and 120 kDa β-galactosidase of Paenibacillus wynnii (β-gal-Pw) was expressed and secreted with B. subtilis SCK6. Different strategies were focused on to identify the best secretion conditions. Tailormade codon-optimization of the β-gal-Pw gene led to an increase in extracellular β-gal-Pw production. Consequently, the optimized gene was used to test four signal peptides and two promoters in different combinations. Differences in extracellular β-gal-Pw activity between the recombinant B. subtilis strains were observed with the successful secretion being highly dependent on the specific combination of promoter and signal peptide used. Interestingly, signal peptides of both the general secretory- and the twin-arginine translocation pathway mediated secretion. The highest extracellular activity of 55.2 ± 6 µkat/Lculture was reached when secretion was mediated by the PhoD signal peptide and expression was controlled by the PAprE promoter. Production of extracellular β-gal-Pw was further enhanced 1.4-fold in a bioreactor cultivation to 77.5 ± 10 µkat/Lculture with secretion efficiencies of more than 80%. CONCLUSION For the first time, the β-gal-Pw was efficiently secreted with B. subtilis SCK6, demonstrating the potential of this strain for secretory production of cytoplasmic, high molecular weight enzymes.
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Affiliation(s)
- Jana Senger
- Institute of Food Science and Biotechnology, Department of Biotechnology and Enzyme Science, University of Hohenheim, Garbenstr. 25, 70599, Stuttgart, Germany
| | - Ines Seitl
- Institute of Food Science and Biotechnology, Department of Biotechnology and Enzyme Science, University of Hohenheim, Garbenstr. 25, 70599, Stuttgart, Germany
| | - Eva Pross
- Institute of Food Science and Biotechnology, Department of Biotechnology and Enzyme Science, University of Hohenheim, Garbenstr. 25, 70599, Stuttgart, Germany
| | - Lutz Fischer
- Institute of Food Science and Biotechnology, Department of Biotechnology and Enzyme Science, University of Hohenheim, Garbenstr. 25, 70599, Stuttgart, Germany.
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2
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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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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. [PMID: 38465694 DOI: 10.1039/d3np00065f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [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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Haq IU, Müller P, Brantl S. A comprehensive study of the interactions in the B. subtilis degradosome with special emphasis on the role of the small proteins SR1P and SR7P. Mol Microbiol 2024; 121:40-52. [PMID: 37994189 DOI: 10.1111/mmi.15195] [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: 10/17/2023] [Revised: 11/09/2023] [Accepted: 11/11/2023] [Indexed: 11/24/2023]
Abstract
Here, we employ coelution experiments and far-western blotting to identify stable interactions between the main components of the B. subtilis degradosome and the small proteins SR1P and SR7P. Our data indicate that B. subtilis has a degradosome comprising at least RNases Y and PnpA, enolase, phosphofructokinase, glycerol-3-phosphate dehydrogenase GapA, and helicase CshA that can be co-purified without cross-linking. All interactions were corroborated by far-western blotting with proteins purified from E. coli. Previously, we discovered that stress-induced SR7P binds enolase to enhance its interaction with and activity of enolase-bound RNase Y (RnY), while SR1P transcribed under gluconeogenic conditions interacts with GapA to stimulate its interaction with and the activity of RnjA (RnjA). We show that SR1P can directly bind RnjA, RnY, and PnpA independently of GapA, whereas SR7P only interacts with enolase. Northern blotting suggests that the degradation of individual RNAs in B. subtilis under gluconeogenic or stress conditions depends on either RnjA or RnY alone or on RnjA-SR1P, RnY-SR1P, or RnY-Eno. In vitro degradation assays with RnY or RnjA substrates corroborate the in vivo role of SR1P. Currently, it is unknown which substrate property is decisive for the utilization of one of the complexes.
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Affiliation(s)
- Inam Ul Haq
- Friedrich-Schiller-Universität Jena, Matthias-Schleiden-Institut, AG Bakteriengenetik, Jena, Germany
| | - Peter Müller
- Friedrich-Schiller-Universität Jena, Matthias-Schleiden-Institut, AG Bakteriengenetik, Jena, Germany
| | - Sabine Brantl
- Friedrich-Schiller-Universität Jena, Matthias-Schleiden-Institut, AG Bakteriengenetik, Jena, Germany
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5
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Jun JS, Jeong HE, Hong KW. Exploring and Engineering Novel Strong Promoters for High-Level Protein Expression in Bacillus subtilis DB104 through Transcriptome Analysis. Microorganisms 2023; 11:2929. [PMID: 38138072 PMCID: PMC10745405 DOI: 10.3390/microorganisms11122929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 12/01/2023] [Accepted: 12/05/2023] [Indexed: 12/24/2023] Open
Abstract
Bacillus subtilis is widely employed for recombinant protein expression. B. subtilis DB104 offers a distinct advantage as a protein expression host because it is an extracellular protease-deficient derivative of B. subtilis 168. We have conducted a time-course transcriptome analysis of B. subtilis DB104 in a prior study. In the present study, we identified 10 genes that exhibited strong expression at each time point or all, based on transcriptome data. Subsequently, we assessed the strength of 12 promoters that transcribe these genes using enhanced green fluorescent protein (eGFP) as a reporter. Among these promoters, Psdp and PskfA had the highest expression levels. At 24 h, these two promoters exhibited 34.5- and 38.8-fold higher strength, respectively, than the strength of P43, the control promoter. Consequently, these two promoters were selected for further development. We enhanced these promoters by optimizing spacer length, promoter sequence, Shine-Dalgarno sequence, regulator binding sites, and terminator sequences. As a result, we successfully engineered the most potent protein expression cassette, Psdp-4, which exhibited a 3.84-fold increase in strength compared to the original Psdp promoter. Furthermore, we constructed an expression cassette for a human epidermal growth factor (hEGF) using Psdp-4 to evaluate its general application. The expression level of His tagged hEGF, quantified using ImageJ analysis and applied to SDS-PAGE, reached the highest yield of 103.9 μg/mL under the control of Psdp-4 at 24 h. The expressed hEGF protein was purified, and its bioactivity was confirmed through a cell proliferation assay using HT-29 cells. Our work demonstrates the construction of a highly efficient expression system for B. subtilis DB104 based on transcriptome data and promoter engineering. This system enables rapid, inducer-free protein expression within 24 h. It can be used as a valuable tool for various industrial applications.
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Affiliation(s)
| | | | - Kwang-Won Hong
- Department of Food Science and Biotechnology, College of Life Science and Biotechnology, Dongguk University, Goyang-si 10326, Republic of Korea; (J.-S.J.); (H.-E.J.)
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6
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Falkenberg F, Kohn S, Bott M, Bongaerts J, Siegert P. Biochemical characterisation of a novel broad pH spectrum subtilisin from Fictibacillus arsenicus DSM 15822 T. FEBS Open Bio 2023; 13:2035-2046. [PMID: 37649135 PMCID: PMC10626276 DOI: 10.1002/2211-5463.13701] [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: 04/25/2023] [Revised: 08/23/2023] [Accepted: 08/29/2023] [Indexed: 09/01/2023] Open
Abstract
Subtilisins from microbial sources, especially from the Bacillaceae family, are of particular interest for biotechnological applications and serve the currently growing enzyme market as efficient and novel biocatalysts. Biotechnological applications include use in detergents, cosmetics, leather processing, wastewater treatment and pharmaceuticals. To identify a possible candidate for the enzyme market, here we cloned the gene of the subtilisin SPFA from Fictibacillus arsenicus DSM 15822T (obtained through a data mining-based search) and expressed it in Bacillus subtilis DB104. After production and purification, the protease showed a molecular mass of 27.57 kDa and a pI of 5.8. SPFA displayed hydrolytic activity at a temperature optimum of 80 °C and a very broad pH optimum between 8.5 and 11.5, with high activity up to pH 12.5. SPFA displayed no NaCl dependence but a high NaCl tolerance, with decreasing activity up to concentrations of 5 m NaCl. The stability enhanced with increasing NaCl concentration. Based on its substrate preference for 10 synthetic peptide 4-nitroanilide substrates with three or four amino acids and its phylogenetic classification, SPFA can be assigned to the subgroup of true subtilisins. Moreover, SPFA exhibited high tolerance to 5% (w/v) SDS and 5% H2 O2 (v/v). The biochemical properties of SPFA, especially its tolerance of remarkably high pH, SDS and H2 O2 , suggest it has potential for biotechnological applications.
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Affiliation(s)
- Fabian Falkenberg
- Institute of Nano‐ and BiotechnologiesAachen University of Applied SciencesJülichGermany
| | - Sophie Kohn
- Institute of Nano‐ and BiotechnologiesAachen University of Applied SciencesJülichGermany
| | - Michael Bott
- Institute of Bio‐ and Geosciences, IBG‐1: BiotechnologyForschungszentrum JülichGermany
| | - Johannes Bongaerts
- Institute of Nano‐ and BiotechnologiesAachen University of Applied SciencesJülichGermany
| | - Petra Siegert
- Institute of Nano‐ and BiotechnologiesAachen University of Applied SciencesJülichGermany
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7
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He B, Sachla AJ, Helmann JD. TerC proteins function during protein secretion to metalate exoenzymes. Nat Commun 2023; 14:6186. [PMID: 37794032 PMCID: PMC10550928 DOI: 10.1038/s41467-023-41896-1] [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: 05/08/2023] [Accepted: 09/14/2023] [Indexed: 10/06/2023] Open
Abstract
Cytosolic metalloenzymes acquire metals from buffered intracellular pools. How exported metalloenzymes are appropriately metalated is less clear. We provide evidence that TerC family proteins function in metalation of enzymes during export through the general secretion (Sec-dependent) pathway. Bacillus subtilis strains lacking MeeF(YceF) and MeeY(YkoY) have a reduced capacity for protein export and a greatly reduced level of manganese (Mn) in the secreted proteome. MeeF and MeeY copurify with proteins of the general secretory pathway, and in their absence the FtsH membrane protease is essential for viability. MeeF and MeeY are also required for efficient function of the Mn2+-dependent lipoteichoic acid synthase (LtaS), a membrane-localized enzyme with an extracytoplasmic active site. Thus, MeeF and MeeY, representative of the widely conserved TerC family of membrane transporters, function in the co-translocational metalation of Mn2+-dependent membrane and extracellular enzymes.
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Affiliation(s)
- Bixi He
- Department of Microbiology, Cornell University, 370 Wing Hall, 123 Wing Drive, Ithaca, NY, 14853-8101, USA
| | - Ankita J Sachla
- Department of Microbiology, Cornell University, 370 Wing Hall, 123 Wing Drive, Ithaca, NY, 14853-8101, USA
| | - John D Helmann
- Department of Microbiology, Cornell University, 370 Wing Hall, 123 Wing Drive, Ithaca, NY, 14853-8101, USA.
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8
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Jun JS, Jeong HE, Moon SY, Shin SH, Hong KW. Time-Course Transcriptome Analysis of Bacillus subtilis DB104 during Growth. Microorganisms 2023; 11:1928. [PMID: 37630488 PMCID: PMC10458515 DOI: 10.3390/microorganisms11081928] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 07/27/2023] [Accepted: 07/28/2023] [Indexed: 08/27/2023] Open
Abstract
Bacillus subtilis DB104, an extracellular protease-deficient derivative of B. subtilis 168, is widely used for recombinant protein expression. An understanding of the changes in gene expression during growth is essential for the commercial use of bacterial strains. Transcriptome and proteome analyses are ideal methods to study the genomic response of microorganisms. In this study, transcriptome analysis was performed to monitor changes in the gene expression level of B. subtilis DB104 while growing on a complete medium. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, K-mean cluster analysis, gene ontology (GO) enrichment analysis, and the function of sigma factors were used to divide 2122 differentially expressed genes (DEGs) into 10 clusters and identified gene functions according to expression patterns. The results of KEGG pathway analysis indicated that ABC transporter is down-regulated during exponential growth and metabolic changes occur at the transition point where sporulation starts. At this point, several stress response genes were also turned on. The genes involved in the lipid catabolic process were up-regulated briefly at 15 h as an outcome of the programmed cell death that postpones sporulation. The results suggest that changes in the gene expression of B. subtilis DB104 were dependent on the initiation of sporulation. However, the expression timing of the spore coat gene was only affected by the relevant sigma factor. This study can help to understand gene expression and regulatory mechanisms in B. subtilis species by providing an overall view of transcriptional changes during the growth of B. subtilis DB104.
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Affiliation(s)
| | | | | | | | - Kwang-Won Hong
- Department of Food Science and Biotechnology, College of Life Science and Biotechnology, Dongguk University, Goyang-si 10326, Republic of Korea; (J.-S.J.); (H.-E.J.); (S.-Y.M.); (S.-H.S.)
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9
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He B, Sachla AJ, Helmann JD. TerC Proteins Function During Protein Secretion to Metalate Exoenzymes. RESEARCH SQUARE 2023:rs.3.rs-2860473. [PMID: 37292672 PMCID: PMC10246235 DOI: 10.21203/rs.3.rs-2860473/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Cytosolic metalloenzymes acquire metals from buffered intracellular pools. How exported metalloenzymes are appropriately metalated is less clear. We provide evidence that TerC family proteins function in metalation of enzymes during export through the general secretion (Sec-dependent) pathway. Bacillus subtilis strains lacking MeeF(YceF) and MeeY(YkoY) have a reduced capacity for protein export and a greatly reduced level of manganese (Mn) in the secreted proteome. MeeF and MeeY copurify with proteins of the general secretory pathway, and in their absence the FtsH membrane protease is essential for viability. MeeF and MeeY are also required for efficient function of the Mn2+-dependent lipoteichoic acid synthase (LtaS), a membrane-localized enzyme with an extracytoplasmic active site. Thus, MeeF and MeeY, representative of the widely conserved TerC family of membrane transporters, function in the co-translocational metalation of Mn2+-dependent membrane and extracellular enzymes.
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Affiliation(s)
- Bixi He
- Department of Microbiology, Cornell University, 370 Wing Hall, 123 Wing Drive, Ithaca, New York 14853-8101, USA
| | - Ankita J. Sachla
- Department of Microbiology, Cornell University, 370 Wing Hall, 123 Wing Drive, Ithaca, New York 14853-8101, USA
| | - John D. Helmann
- Department of Microbiology, Cornell University, 370 Wing Hall, 123 Wing Drive, Ithaca, New York 14853-8101, USA
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10
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Falkenberg F, Voß L, Bott M, Bongaerts J, Siegert P. New robust subtilisins from halotolerant and halophilic Bacillaceae. Appl Microbiol Biotechnol 2023:10.1007/s00253-023-12553-w. [PMID: 37160606 DOI: 10.1007/s00253-023-12553-w] [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: 03/21/2023] [Revised: 04/17/2023] [Accepted: 04/19/2023] [Indexed: 05/11/2023]
Abstract
The aim of the present study was the characterisation of three true subtilisins and one phylogenetically intermediate subtilisin from halotolerant and halophilic microorganisms. Considering the currently growing enzyme market for efficient and novel biocatalysts, data mining is a promising source for novel, as yet uncharacterised enzymes, especially from halophilic or halotolerant Bacillaceae, which offer great potential to meet industrial needs. Both halophilic bacteria Pontibacillus marinus DSM 16465T and Alkalibacillus haloalkaliphilus DSM 5271T and both halotolerant bacteria Metabacillus indicus DSM 16189 and Litchfieldia alkalitelluris DSM 16976T served as a source for the four new subtilisins SPPM, SPAH, SPMI and SPLA. The protease genes were cloned and expressed in Bacillus subtilis DB104. Purification to apparent homogeneity was achieved by ethanol precipitation, desalting and ion-exchange chromatography. Enzyme activity could be observed between pH 5.0-12.0 with an optimum for SPPM, SPMI and SPLA around pH 9.0 and for SPAH at pH 10.0. The optimal temperature for SPMI and SPLA was 70 °C and for SPPM and SPAH 55 °C and 50 °C, respectively. All proteases showed high stability towards 5% (w/v) SDS and were active even at NaCl concentrations of 5 M. The four proteases demonstrate potential for future biotechnological applications. KEY POINTS: • Halophilic and halotolerant Bacillaceae are a valuable source of new subtilisins. • Four new subtilisins were biochemically characterised in detail. • The four proteases show potential for future biotechnological applications.
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Affiliation(s)
- Fabian Falkenberg
- Institute of Nano- and Biotechnologies, Aachen University of Applied Sciences, 52428, Jülich, Germany
| | - Leonie Voß
- Institute of Nano- and Biotechnologies, Aachen University of Applied Sciences, 52428, Jülich, Germany
| | - Michael Bott
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Johannes Bongaerts
- Institute of Nano- and Biotechnologies, Aachen University of Applied Sciences, 52428, Jülich, Germany
| | - Petra Siegert
- Institute of Nano- and Biotechnologies, Aachen University of Applied Sciences, 52428, Jülich, Germany.
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11
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He B, Sachla AJ, Helmann JD. TerC Proteins Function During Protein Secretion to Metalate Exoenzymes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.10.536223. [PMID: 37090602 PMCID: PMC10120614 DOI: 10.1101/2023.04.10.536223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Cytosolic metalloenzymes acquire metals from buffered intracellular pools. How exported metalloenzymes are appropriately metalated is less clear. We provide evidence that TerC family proteins function in metalation of enzymes during export through the general secretion (Sec-dependent) pathway. Bacillus subtilis strains lacking MeeF(YceF) and MeeY(YkoY) have a reduced capacity for protein export and a greatly reduced level of manganese (Mn) in the secreted proteome. MeeF and MeeY copurify with proteins of the general secretory pathway, and in their absence the FtsH membrane protease is essential for viability. MeeF and MeeY are also required for efficient function of the Mn 2+ -dependent lipoteichoic acid synthase (LtaS), a membrane-localized enzyme with an extracytoplasmic active site. Thus, MeeF and MeeY, representative of the widely conserved TerC family of membrane transporters, function in the co-translocational metalation of Mn 2+ -dependent membrane and extracellular enzymes.
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Affiliation(s)
- Bixi He
- Department of Microbiology, Cornell University, 370 Wing Hall, 123 Wing Drive, Ithaca, New York 14853-8101, USA
| | - Ankita J. Sachla
- Department of Microbiology, Cornell University, 370 Wing Hall, 123 Wing Drive, Ithaca, New York 14853-8101, USA
| | - John D. Helmann
- Department of Microbiology, Cornell University, 370 Wing Hall, 123 Wing Drive, Ithaca, New York 14853-8101, USA
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12
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Cannon JA, Reynolds TB. Synergistic Mutations Create Bacillus Subtilisin Variants with Enhanced Poly-l-Lactic Acid Depolymerization Activity. Biomacromolecules 2023; 24:1141-1154. [PMID: 36780360 DOI: 10.1021/acs.biomac.2c01198] [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: 02/14/2023]
Abstract
Enzymatic recycling of poly-l-lactic acid (PLLA) plastic has recently become an area of interest; however, investigation of enzymatic mechanisms and engineering strategies to improve activity remains limited. In this study, we have identified a subtilisin from Bacillus pumilus that has the ability to depolymerize high-molecular-weight PLLA. We performed a comparative, mutational analysis of this enzyme with a less active homologue from Bacillus subtilis to determine residues favored for activity. Our results demonstrate that both enzymes contain residues favored for PLLA depolymerization, with the generation of several hyperactive variants. In silico modeling suggests that increases in activity are due to opening of the binding pockets and increased surface hydrophobicity. Combinations of hyperactive mutations have synergistic effects with the generation of subtilisin variants with 830- and 184-fold increases in activity for B. subtilis and B. pumilus subtilisins, respectively. One B. pumilus subtilisin variant can visibly dissolve high-molecular-weight PLLA films.
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Affiliation(s)
- Jordan A Cannon
- Department of Microbiology, University of Tennessee at Knoxville, Knoxville, Tennessee 37996, United States
| | - Todd B Reynolds
- Department of Microbiology, University of Tennessee at Knoxville, Knoxville, Tennessee 37996, United States
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13
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Grasso S, Dabene V, Hendriks MMW, Zwartjens P, Pellaux R, Held M, Panke S, van Dijl JM, Meyer A, van Rij T. Signal Peptide Efficiency: From High-Throughput Data to Prediction and Explanation. ACS Synth Biol 2023; 12:390-404. [PMID: 36649479 PMCID: PMC9942255 DOI: 10.1021/acssynbio.2c00328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The passage of proteins across biological membranes via the general secretory (Sec) pathway is a universally conserved process with critical functions in cell physiology and important industrial applications. Proteins are directed into the Sec pathway by a signal peptide at their N-terminus. Estimating the impact of physicochemical signal peptide features on protein secretion levels has not been achieved so far, partially due to the extreme sequence variability of signal peptides. To elucidate relevant features of the signal peptide sequence that influence secretion efficiency, an evaluation of ∼12,000 different designed signal peptides was performed using a novel miniaturized high-throughput assay. The results were used to train a machine learning model, and a post-hoc explanation of the model is provided. By describing each signal peptide with a selection of 156 physicochemical features, it is now possible to both quantify feature importance and predict the protein secretion levels directed by each signal peptide. Our analyses allow the detection and explanation of the relevant signal peptide features influencing the efficiency of protein secretion, generating a versatile tool for the de novo design and in silico evaluation of signal peptides.
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Affiliation(s)
- Stefano Grasso
- Department
of Medical Microbiology, University of Groningen,
University Medical Center Groningen, Hanzeplein 1, Groningen 9700 RB, The Netherlands,DSM
Biotechnology Center, Alexander Fleminglaan 1, Delft 2613 AX, Netherlands
| | - Valentina Dabene
- Department
of Biosystems Science and Engineering, ETH
Zurich, Mattenstrasse
26, Basel 4058, Switzerland,FGen
AG, Hochbergerstrasse
60C, Basel 4057, Switzerland
| | | | - Priscilla Zwartjens
- DSM
Biotechnology Center, Alexander Fleminglaan 1, Delft 2613 AX, Netherlands
| | - René Pellaux
- FGen
AG, Hochbergerstrasse
60C, Basel 4057, Switzerland
| | - Martin Held
- Department
of Biosystems Science and Engineering, ETH
Zurich, Mattenstrasse
26, Basel 4058, Switzerland
| | - Sven Panke
- Department
of Biosystems Science and Engineering, ETH
Zurich, Mattenstrasse
26, Basel 4058, Switzerland
| | - Jan Maarten van Dijl
- Department
of Medical Microbiology, University of Groningen,
University Medical Center Groningen, Hanzeplein 1, Groningen 9700 RB, The Netherlands,. Phone: +31503615187
| | - Andreas Meyer
- FGen
AG, Hochbergerstrasse
60C, Basel 4057, Switzerland
| | - Tjeerd van Rij
- DSM
Biotechnology Center, Alexander Fleminglaan 1, Delft 2613 AX, Netherlands,. Phone: +31628441843
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14
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Falkenberg F, Rahba J, Fischer D, Bott M, Bongaerts J, Siegert P. Biochemical characterization of a novel oxidatively stable, halotolerant, and high-alkaline subtilisin from Alkalihalobacillus okhensis Kh10-101 T. FEBS Open Bio 2022; 12:1729-1746. [PMID: 35727859 PMCID: PMC9527586 DOI: 10.1002/2211-5463.13457] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/13/2022] [Accepted: 06/20/2022] [Indexed: 12/14/2022] Open
Abstract
Halophilic and halotolerant microorganisms represent a promising source of salt-tolerant enzymes suitable for various biotechnological applications where high salt concentrations would otherwise limit enzymatic activity. Considering the current growing enzyme market and the need for more efficient and new biocatalysts, the present study aimed at the characterization of a high-alkaline subtilisin from Alkalihalobacillus okhensis Kh10-101T . The protease gene was cloned and expressed in Bacillus subtilis DB104. The recombinant protease SPAO with 269 amino acids belongs to the subfamily of high-alkaline subtilisins. The biochemical characteristics of purified SPAO were analyzed in comparison with subtilisin Carlsberg, Savinase, and BPN'. SPAO, a monomer with a molecular mass of 27.1 kDa, was active over a wide range of pH 6.0-12.0 and temperature 20-80 °C, optimally at pH 9.0-9.5 and 55 °C. The protease is highly oxidatively stable to hydrogen peroxide and retained 58% of residual activity when incubated at 10 °C with 5% (v/v) H2 O2 for 1 h while stimulated at 1% (v/v) H2 O2 . Furthermore, SPAO was very stable and active at NaCl concentrations up to 5.0 m. This study demonstrates the potential of SPAO for biotechnological applications in the future.
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Affiliation(s)
- Fabian Falkenberg
- Institute of Nano‐ and BiotechnologiesAachen University of Applied SciencesJülichGermany
| | - Jade Rahba
- Institute of Nano‐ and BiotechnologiesAachen University of Applied SciencesJülichGermany
| | - David Fischer
- Institute of Nano‐ and BiotechnologiesAachen University of Applied SciencesJülichGermany
| | - Michael Bott
- Institute of Bio‐ and GeosciencesIBG‐1: Biotechnology, Forschungszentrum JülichGermany
| | - Johannes Bongaerts
- Institute of Nano‐ and BiotechnologiesAachen University of Applied SciencesJülichGermany
| | - Petra Siegert
- Institute of Nano‐ and BiotechnologiesAachen University of Applied SciencesJülichGermany
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15
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Chen W, Li L, Ye C, Zhao Z, Huang K, Zou D, Wei X. Efficient production of extracellular alkaline protease in Bacillus amyloliquefaciens by host strain construction. Lebensm Wiss Technol 2022. [DOI: 10.1016/j.lwt.2022.113620] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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16
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Ye J, Li Y, Bai Y, Zhang T, Jiang W, Shi T, Wu Z, Zhang YHPJ. A facile and robust T7-promoter-based high-expression of heterologous proteins in Bacillus subtilis. BIORESOUR BIOPROCESS 2022; 9:56. [PMID: 38647747 PMCID: PMC10991129 DOI: 10.1186/s40643-022-00540-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 04/27/2022] [Indexed: 11/10/2022] Open
Abstract
To mimic the Escherichia coli T7 protein expression system, we developed a facile T7 promoter-based protein expression system in an industrial microorganism Bacillus subtilis. This system has two parts: a new B. subtilis strain SCK22 and a plasmid pHT7. To construct strain SCK22, the T7 RNA polymerase gene was inserted into the chromosome, and several genes, such as two major protease genes, a spore generation-related gene, and a fermentation foam generation-related gene, were knocked out to facilitate good expression in high-density cell fermentation. The gene of a target protein can be subcloned into plasmid pHT7, where the gene of the target protein was under tight control of the T7 promoter with a ribosome binding site (RBS) sequence of B. subtilis (i.e., AAGGAGG). A few recombinant proteins (i.e., green fluorescent protein, α-glucan phosphorylase, inositol monophosphatase, phosphoglucomutase, and 4-α-glucanotransferase) were expressed with approximately 25-40% expression levels relative to the cellular total proteins estimated by SDS-PAGE by using B. subtilis SCK22/pHT7-derived plasmid. A fed-batch high-cell density fermentation was conducted in a 5-L fermenter, producing up to 4.78 g/L inositol monophosphatase. This expression system has a few advantageous features, such as, wide applicability for recombinant proteins, high protein expression level, easy genetic operation, high transformation efficiency, good genetic stability, and suitability for high-cell density fermentation.
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Affiliation(s)
- Jing Ye
- Tianjin Key Laboratory of Food Science and Biotechnology, College of Biotechnology and Food Science, Tianjin University of Commerce, Tianjin, China
| | - Yunjie Li
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China
| | - Yuqing Bai
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China
| | - Ting Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China
| | - Wei Jiang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China
| | - Ting Shi
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China.
| | - Zijian Wu
- Tianjin Key Laboratory of Food Science and Biotechnology, College of Biotechnology and Food Science, Tianjin University of Commerce, Tianjin, China.
| | - Yi-Heng P Job Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China.
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17
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Bruce JB, Lion S, Buckling A, Westra ER, Gandon S. Regulation of prophage induction and lysogenization by phage communication systems. Curr Biol 2021; 31:5046-5051.e7. [PMID: 34562385 PMCID: PMC8612742 DOI: 10.1016/j.cub.2021.08.073] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/20/2021] [Accepted: 08/31/2021] [Indexed: 11/25/2022]
Abstract
Many viruses cause both lytic infections, where they release viral particles, and dormant infections, where they await future opportunities to reactivate.1 The benefits of each transmission mode depend on the density of susceptible hosts in the environment.2-4 Some viruses infecting bacteria use molecular signaling to respond plastically to changes in host availability.5 These viruses produce a signal during lytic infection and regulate, based on the signal concentration in the environment, the probability with which they switch to causing dormant infections.5,6 We present an analytical framework to examine the adaptive significance of plasticity in viral life-history traits in fluctuating environments. Our model generalizes and extends previous theory7 and predicts that host density fluctuations should select for plasticity in entering lysogeny as well as virus reactivation once signal concentrations decline. Using Bacillus subtilis and its phage phi3T, we experimentally confirm the prediction that phages use signal to make informed decisions over prophage induction. We also demonstrate that lysogens produce signaling molecules and that signal is degraded by hosts in a density-dependent manner. Declining signal concentrations therefore potentially indicate the presence of uninfected hosts and trigger prophage induction. Finally, we find that conflict over the responses of lysogenization and reactivation to signal is resolved through the evolution of different response thresholds for each trait. Collectively, these findings deepen our understanding of the ways viruses use molecular communication to regulate their infection strategies, which can be leveraged to manipulate host and phage population dynamics in natural environments.
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Affiliation(s)
- John B Bruce
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Exeter, UK.
| | - Sébastien Lion
- CEFE, CNRS, Univ Montpellier, EPHE, IRD, Univ Paul Valéry Montpellier 3, Montpellier, France
| | - Angus Buckling
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Exeter, UK
| | - Edze R Westra
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Exeter, UK.
| | - Sylvain Gandon
- CEFE, CNRS, Univ Montpellier, EPHE, IRD, Univ Paul Valéry Montpellier 3, Montpellier, France.
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18
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Galano M, van den Dungen MW, van Rij T, Abbas HE. Safety evaluation of food enzymes produced by a safe strain lineage of Bacillussubtilis. Regul Toxicol Pharmacol 2021; 126:105030. [PMID: 34455008 DOI: 10.1016/j.yrtph.2021.105030] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 08/16/2021] [Accepted: 08/18/2021] [Indexed: 11/30/2022]
Abstract
The safety of microbially-derived food enzymes must be carefully assessed before market introduction. The production strain's safety is central to the assessment. In this paper, we have determined that DSM's Bacillus subtilis strain lineage can be considered safe for food enzyme production. The mutations introduced into this non-pathogenic and non-toxigenic microorganism do not lead to any safety concerns, as ensured by a thorough characterization of the strain lineage. The safety of both targeted and randomly introduced changes into the production strain's genome is confirmed by validating the absence of vector sequences and antibiotic resistance genes in all relevant production strains, and by demonstrating absence of cytotoxic peptide production. Furthermore, three food enzyme preparations produced by strains within this lineage did not show genotoxic potential. 90-day oral toxicity studies performed with the same enzyme preparations did not reveal toxicologically significant adverse effects. These results demonstrate absence of safety concerns from the introduced genetic modifications. Based on the establishment of this safe strain lineage, we postulate that future enzymes produced by current and new strains derived from the lineage can be safely developed without additional genotoxicity and systemic toxicity studies, allowing for a reduction of animal testing without compromising on product safety.
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Affiliation(s)
- Melina Galano
- DSM Food Specialties B.V., Alexander Fleminglaan 1, 2613 AX, Delft, the Netherlands.
| | | | - Tjeerd van Rij
- DSM Food Specialties B.V., Alexander Fleminglaan 1, 2613 AX, Delft, the Netherlands
| | - Hanna E Abbas
- DSM Food Specialties B.V., Alexander Fleminglaan 1, 2613 AX, Delft, the Netherlands
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19
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Harwood CR, Kikuchi Y. The ins and outs of Bacillus proteases: activities, functions and commercial significance. FEMS Microbiol Rev 2021; 46:6354784. [PMID: 34410368 PMCID: PMC8767453 DOI: 10.1093/femsre/fuab046] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 08/17/2021] [Indexed: 12/23/2022] Open
Abstract
Because the majority of bacterial species divide by binary fission, and do not have distinguishable somatic and germline cells, they could be considered to be immortal. However, bacteria ‘age’ due to damage to vital cell components such as DNA and proteins. DNA damage can often be repaired using efficient DNA repair mechanisms. However, many proteins have a functional ‘shelf life’; some are short lived, while others are relatively stable. Specific degradation processes are built into the life span of proteins whose activities are required to fulfil a specific function during a prescribed period of time (e.g. cell cycle, differentiation process, stress response). In addition, proteins that are irreparably damaged or that have come to the end of their functional life span need to be removed by quality control proteases. Other proteases are involved in performing a variety of specific functions that can be broadly divided into three categories: processing, regulation and feeding. This review presents a systematic account of the proteases of Bacillus subtilis and their activities. It reviews the proteases found in, or associated with, the cytoplasm, the cell membrane, the cell wall and the external milieu. Where known, the impacts of the deletion of particular proteases are discussed, particularly in relation to industrial applications.
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Affiliation(s)
- Colin R Harwood
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University NE2 4AX, Newcastle upon Tyne, UK
| | - Yoshimi Kikuchi
- Research Institute for Bioscience Products & Fine Chemicals, Ajinomoto Co., Inc., Kawasaki 210-8681, JAPAN
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20
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Recombinant protein secretion by Bacillus subtilis and Lactococcus lactis: pathways, applications, and innovation potential. Essays Biochem 2021; 65:187-195. [PMID: 33955475 PMCID: PMC8314018 DOI: 10.1042/ebc20200171] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 04/15/2021] [Accepted: 04/16/2021] [Indexed: 01/01/2023]
Abstract
Secreted recombinant proteins are of great significance for industry, healthcare and a sustainable bio-based economy. Consequently, there is an ever-increasing need for efficient production platforms to deliver such proteins in high amounts and high quality. Gram-positive bacteria, particularly bacilli such as Bacillus subtilis, are favored for the production of secreted industrial enzymes. Nevertheless, recombinant protein production in the B. subtilis cell factory can be very challenging due to bottlenecks in the general (Sec) secretion pathway as well as this bacterium’s intrinsic capability to secrete a cocktail of highly potent proteases. This has placed another Gram-positive bacterium, Lactococcus lactis, in the focus of attention as an alternative, non-proteolytic, cell factory for secreted proteins. Here we review our current understanding of the secretion pathways exploited in B. subtilis and L. lactis to deliver proteins from their site of synthesis, the cytoplasm, into the fermentation broth. An advantage of this cell factory comparison is that it identifies opportunities for protein secretion pathway engineering to remove or bypass current production bottlenecks. Noteworthy new developments in cell factory engineering are the mini-Bacillus concept, highlighting potential advantages of massive genome minimization, and the application of thus far untapped ‘non-classical’ protein secretion routes. Altogether, it is foreseen that engineered lactococci will find future applications in the production of high-quality proteins at the relatively small pilot scale, while engineered bacilli will remain a favored choice for protein production in bulk.
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21
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Kim D, Kim W, Kim J. New Bacterial Surface Display System Development and Application Based on Bacillus subtilis YuaB Biofilm Component as an Anchoring Motif. BIOTECHNOL BIOPROC E 2021; 26:39-46. [PMID: 33584103 PMCID: PMC7872719 DOI: 10.1007/s12257-020-0397-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/07/2021] [Accepted: 01/07/2021] [Indexed: 12/11/2022]
Abstract
Bacterial surface display system has been adopted in various biotechnological applications. In the case of Bacillus subtilis, most of the studies have been developed using spore based surface display system utilizing the inherent rigidity of spore against heat, alkali, and shear stress. But, spore harvest, purification and separation need additional cost and labor. To eliminate this procedure and to use the gram-positive nature of B. subtilis, YuaB, which is one of the major B. subtilis biofilm components and locates in the cell wall, based cell surface display system, is developed. P43 promoter driven overexpression of YuaB-His6 tag does not hamper bacterial cell growth and promoted biofilm formation of recombinant strain. Flow cytometry of recombinant strain and its protoplast using FITC-Anti His6 antibody, verified that YuaB locate in plasma membrane and protrude to the outside of cell wall, which means YuaB can be used as very efficient anchoring motif. Using surface expressed YuaB-His6 tag, removal of divalent metal ion, Cu2+ and Ni2+, was tried to test its possibility for the environmental application of developed system.
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Affiliation(s)
- Daeun Kim
- Department of Chemical Engineer, Dong-A University, Busan, 49315 Korea
| | - Wooil Kim
- Department of Chemical Engineer, Dong-A University, Busan, 49315 Korea
| | - Junehyung Kim
- Department of Chemical Engineer, Dong-A University, Busan, 49315 Korea.,Center for Sliver-Targeted Biomaterials, Brain Busan 21 Plus Program, Graduate School, Dong-A University, Busan, 49315 Korea
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22
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Engineering Bacillus subtilis Cells as Factories: Enzyme Secretion and Value-added Chemical Production. BIOTECHNOL BIOPROC E 2020. [DOI: 10.1007/s12257-020-0104-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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23
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Yao Z, Meng Y, Le HG, Lee SJ, Jeon HS, Yoo JY, Kim HJ, Kim JH. Cloning of a Novel vpr Gene Encoding a Minor Fibrinolytic Enzyme from Bacillus subtilis SJ4 and the Properties of Vpr. J Microbiol Biotechnol 2020; 30:1720-1728. [PMID: 32830189 PMCID: PMC9728201 DOI: 10.4014/jmb.2006.06014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 08/14/2020] [Accepted: 08/18/2020] [Indexed: 12/15/2022]
Abstract
We have previously characterized AprESJ4, the major fibrinolytic enzyme from Bacillus subtilis SJ4 (Yao et al., 2019). During that study, we observed a 68 kDa protein with fibrinolytic activity. In this study, we cloned the gene (vprSJ4) encoding the 68 kDa protein, a mature Vpr and minor protease secreted by Bacillus species. vprSJ4 encodes a preproenzyme consisting of 810 amino acids (aa) including signal sequence (28 aa) and prosequence (132 aa). The mature enzyme (650 aa) has a predicted molecular weight of 68,467.35. Unlike Vprs from other B. subtilis strains, VprSJ4 has 4 additional amino acids (DEFA) at the C-terminus. vprSJ4 was overexpressed in Escherichia coli. PreproVprSJ4 was localized in inclusion bodies, and subjected to in vitro renaturation and purification by an affinity column. SDS-PAGE and western blot showed that autoprocessing of preproVprSJ4 occurred and 68 kDa and smaller proteins were produced. The optimum pH and temperature of the recombinant VprSJ4 were pH 7.0 and 40°C, respectively. Kinetic parameters of recombinant VprSJ4 were measured by using an artificial substrate, N-succinyl-ala-ala-pro-phe-p-nitroanilide. Coexpression of vprSJ4 and aprESJ4 using pHY300PLK increased the fibrinolytic activity a further 117% when compared with aprESJ4 single expression using the same vector in B. subtilis WB600.
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Affiliation(s)
- Zhuang Yao
- Division of Applied Life Science (BK2 Four), Graduate School, Gyeongsang National University, Jinju 52828, Republic of Korea
| | - Yu Meng
- Division of Applied Life Science (BK2 Four), Graduate School, Gyeongsang National University, Jinju 52828, Republic of Korea
| | - Huong Giang Le
- Division of Applied Life Science (BK2 Four), Graduate School, Gyeongsang National University, Jinju 52828, Republic of Korea
| | - Se Jin Lee
- Division of Applied Life Science (BK2 Four), Graduate School, Gyeongsang National University, Jinju 52828, Republic of Korea
| | - Hye Sung Jeon
- Division of Applied Life Science (BK2 Four), Graduate School, Gyeongsang National University, Jinju 52828, Republic of Korea
| | - Ji Yeon Yoo
- Division of Applied Life Science (BK2 Four), Graduate School, Gyeongsang National University, Jinju 52828, Republic of Korea
| | - Hyun-Jin Kim
- Division of Applied Life Science (BK2 Four), Graduate School, Gyeongsang National University, Jinju 52828, Republic of Korea,Institute of Agriculture and Life Science, Gyeongsang National University, Jinju 588, Republic of Korea
| | - Jeong Hwan Kim
- Division of Applied Life Science (BK2 Four), Graduate School, Gyeongsang National University, Jinju 52828, Republic of Korea,Institute of Agriculture and Life Science, Gyeongsang National University, Jinju 588, Republic of Korea,Corresponding author Phone: +82-55-772-1904 Fax: +82-55-772-1909 E-mail:
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24
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Mechanisms for Induction of Microbial Extracellular Proteases in Response to Exterior Proteins. Appl Environ Microbiol 2020; 86:AEM.01036-20. [PMID: 32709731 DOI: 10.1128/aem.01036-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Proteins are a main organic nitrogen source for microorganisms. Many heterotrophic microorganisms secrete extracellular proteases (ex-proteases) to efficiently decompose proteins into oligopeptides and amino acids when exterior proteins are required for growth. These ex-proteases not only play important roles in microbial nutrient acquisition or host infection but also contribute greatly to the global recycling of carbon and nitrogen. Moreover, may microbial ex-proteases have important applications in industrial, medical, and biotechnological areas. Therefore, uncovering the mechanisms by which microorganisms initiate the expression of ex-protease genes in response to exterior proteins is of great significance. In this review, the progress made in understanding the induction mechanisms of microbial ex-proteases in response to exterior proteins is summarized, with a focus on the inducer molecules, membrane sensors, and downstream pathways. Problems to be solved for better understanding of the induction mechanisms of microbial ex-proteases are also discussed.
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25
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Abstract
Here, we describe SR7, a dual-function antisense RNA encoded on the Bacillus subtilis chromosome. This RNA was earlier described as SigB-dependent regulatory RNA S1136 and reported to reduce the amount of the small ribosomal subunit under ethanol stress. We found that the 5ʹ portion of SR7 encodes a small protein composed of 39 amino acids which we designated SR7P. It is translated from a 185 nt SigB-dependent mRNA under five different stress conditions and a longer SigB-independent RNA constitutively. About three-fold higher amounts of SR7P were detected in B. subtilis cells exposed to salt, ethanol, acid or heat stress. Co-elution experiments with SR7PC-FLAG and Far-Western blotting demonstrated that SR7P interacts with the glycolytic enzyme enolase. Enolase is a scaffolding component of the B. subtilis degradosome where it interacts with RNase Y and phosphofructokinase PfkA. We found that SR7P increases the amount of RNase Y bound to enolase without affecting PfkA. RNA does not bridge the SR7P-enolase-RNase Y interaction. In vitro-degradation assays with the known RNase Y substrates yitJ and rpsO mRNA revealed enhanced enzymatic activity of enolase-bound RNase Y in the presence of SR7P. Northern blots showed a major effect of enolase and a minor effect of SR7P on the half-life of rpsO mRNA indicating a fine-tuning role of SR7P in RNA degradation.
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Affiliation(s)
- Inam Ul Haq
- Friedrich-Schiller-Universität Jena, Matthias-Schleiden-Institut , AG Bakteriengenetik, Jena, Germany
| | - Peter Müller
- Friedrich-Schiller-Universität Jena, Matthias-Schleiden-Institut , AG Bakteriengenetik, Jena, Germany
| | - Sabine Brantl
- Friedrich-Schiller-Universität Jena, Matthias-Schleiden-Institut , AG Bakteriengenetik, Jena, Germany
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26
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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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Zhou C, Zhou H, Fang H, Ji Y, Wang H, Liu F, Zhang H, Lu F. Spo0A can efficiently enhance the expression of the alkaline protease gene aprE in Bacillus licheniformis by specifically binding to its regulatory region. Int J Biol Macromol 2020; 159:444-454. [PMID: 32437805 DOI: 10.1016/j.ijbiomac.2020.05.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 05/04/2020] [Accepted: 05/05/2020] [Indexed: 02/06/2023]
Abstract
The expression of enzymes in Bacillus licheniformis, such as the valuable extracellular alkaline protease AprE, is highly regulated by a complex transcriptional regulation mechanism. Here, we found that the transcript abundance of aprE varies >343-fold in response to the supply of nutrients or to environmental challenges. To identify the underlying regulatory mechanism, the core promoter of aprE and several important upstream regulatory regions outside the promoter were firstly confirmed by 5'-RACE and mutagenesis experiments. The specific proteins that bind to the identified sequences were subsequently captured by DNA pull-down experiments, which yielded the transcriptional factors (TFs) Spo0A, CggR, FruR, YhcZ, as well as fragments of functionally unassigned proteins. Further electrophoretic mobility shift assay (EMSA) and DNase I foot-printing experiments indicated that Spo0A can directly bind to the region from -92 to -118 nucleotides upstream of the transcription start site, and the deletion of this specific region drastically decreased the production of AprE. Taken together, these results indicated that the expression of aprE was mainly regulated by the interplay between Spo0A and its cognate DNA sequence, which was successfully applied to overproduce AprE in a genetically modified host harboring three aprE expression cassettes. The DNA binding proteins may serve to increase the efficiency of transcription by creating an additional binding site for RNA polymerase. The discovery of this mechanism significantly increases our understanding of the aprE transcription mechanism, which is of great importance for AprE overproduction.
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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, Tianjin 300450, PR China; School of biology and brewing engineering, Taishan University, Taian 271018, 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
| | - Honglei Fang
- Key laboratory of industrial fermentation microbiology, ministry of education, College of biotechnology, Tianjin University of Science &Technology, Tianjin 300450, PR China
| | - Yizhi Ji
- Beijing Key Laboratory of Biomass Waste Resource Utilization, College of Biochemistry and Engineering, Beijing Union University, Beijing 100023, PR China
| | - Hongbin Wang
- Key laboratory of industrial fermentation microbiology, ministry of education, College of biotechnology, Tianjin University of Science &Technology, Tianjin 300450, PR China
| | - Fufeng Liu
- Key laboratory of industrial fermentation microbiology, ministry of education, College of biotechnology, Tianjin University of Science &Technology, Tianjin 300450, 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.
| | - 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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Su HH, Chen JC, Chen PT. Production of recombinant human epidermal growth factor in Bacillus subtilis. J Taiwan Inst Chem Eng 2020. [DOI: 10.1016/j.jtice.2019.10.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Wei R, Breite D, Song C, Gräsing D, Ploss T, Hille P, Schwerdtfeger R, Matysik J, Schulze A, Zimmermann W. Biocatalytic Degradation Efficiency of Postconsumer Polyethylene Terephthalate Packaging Determined by Their Polymer Microstructures. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2019; 6:1900491. [PMID: 31380212 PMCID: PMC6662049 DOI: 10.1002/advs.201900491] [Citation(s) in RCA: 113] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 04/24/2019] [Indexed: 05/09/2023]
Abstract
Polyethylene terephthalate (PET) is the most important mass-produced thermoplastic polyester used as a packaging material. Recently, thermophilic polyester hydrolases such as TfCut2 from Thermobifida fusca have emerged as promising biocatalysts for an eco-friendly PET recycling process. In this study, postconsumer PET food packaging containers are treated with TfCut2 and show weight losses of more than 50% after 96 h of incubation at 70 °C. Differential scanning calorimetry analysis indicates that the high linear degradation rates observed in the first 72 h of incubation is due to the high hydrolysis susceptibility of the mobile amorphous fraction (MAF) of PET. The physical aging process of PET occurring at 70 °C is shown to gradually convert MAF to polymer microstructures with limited accessibility to enzymatic hydrolysis. Analysis of the chain-length distribution of degraded PET by nuclear magnetic resonance spectroscopy reveals that MAF is rapidly hydrolyzed via a combinatorial exo- and endo-type degradation mechanism whereas the remaining PET microstructures are slowly degraded only by endo-type chain scission causing no detectable weight loss. Hence, efficient thermostable biocatalysts are required to overcome the competitive physical aging process for the complete degradation of postconsumer PET materials close to the glass transition temperature of PET.
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Affiliation(s)
- Ren Wei
- Department of Microbiology and Bioprocess TechnologyInstitute of BiochemistryLeipzig UniversityJohannisallee 23D‐04103LeipzigGermany
| | - Daniel Breite
- Leibniz Institute of Surface Engineering (IOM)Permoserstrasse 15D‐04318LeipzigGermany
| | - Chen Song
- Institute of Analytical ChemistryLeipzig UniversityLinnéstrasse 3D‐04103LeipzigGermany
| | - Daniel Gräsing
- Institute of Analytical ChemistryLeipzig UniversityLinnéstrasse 3D‐04103LeipzigGermany
| | - Tina Ploss
- AB Enzymes GmbHFeldbergstrasse 78D‐64293DarmstadtGermany
| | - Patrick Hille
- Department of Microbiology and Bioprocess TechnologyInstitute of BiochemistryLeipzig UniversityJohannisallee 23D‐04103LeipzigGermany
| | | | - Jörg Matysik
- Institute of Analytical ChemistryLeipzig UniversityLinnéstrasse 3D‐04103LeipzigGermany
| | - Agnes Schulze
- Leibniz Institute of Surface Engineering (IOM)Permoserstrasse 15D‐04318LeipzigGermany
| | - Wolfgang Zimmermann
- Department of Microbiology and Bioprocess TechnologyInstitute of BiochemistryLeipzig UniversityJohannisallee 23D‐04103LeipzigGermany
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Müller P, Gimpel M, Wildenhain T, Brantl S. A new role for CsrA: promotion of complex formation between an sRNA and its mRNA target in Bacillus subtilis. RNA Biol 2019; 16:972-987. [PMID: 31043113 PMCID: PMC6546359 DOI: 10.1080/15476286.2019.1605811] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
CsrA is a widely conserved, abundant small RNA binding protein that has been found in E. coli and other Gram-negative bacteria where it is involved in the regulation of carbon metabolism, biofilm formation and virulence. CsrA binds to single-stranded GGA motifs around the SD sequence of target mRNAs where it inhibits or activates translation or influences RNA processing. Small RNAs like CsrB or CsrC containing 13–22 GGA motifs can sequester CsrA, thereby abrogating the effect of CsrA on its target mRNAs. In B. subtilis, CsrA has so far only been found to regulate one target, hag mRNA and to be sequestered by a protein (FliW) and not by an sRNA. Here, we employ a combination of in vitro and in vivo methods to investigate the effect of CsrA on the small regulatory RNA SR1 from B. subtilis, its primary target ahrC mRNA and its downstream targets, the rocABC and rocDEF operons. We demonstrate that CsrA can promote the base-pairing interactions between SR1 and ahrC mRNA, a function that has so far only been found for Hfq or ProQ. Abbreviations: aa, amino acid; bp, basepair; nt, nucleotide; PAA, polyacrylamide; SD, Shine Dalgarno.
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Affiliation(s)
- Peter Müller
- a Matthias-Schleiden-Institut für Genetik, Bioinformatik und Molekulare Botanik, AG Bakteriengenetik , Friedrich-Schiller-Universität Jena , Jena , Germany
| | - Matthias Gimpel
- a Matthias-Schleiden-Institut für Genetik, Bioinformatik und Molekulare Botanik, AG Bakteriengenetik , Friedrich-Schiller-Universität Jena , Jena , Germany.,b Institut für Biotechnologie , Fachgebiet Bioverfahrenstechnik , Berlin , Germany
| | - Theresa Wildenhain
- a Matthias-Schleiden-Institut für Genetik, Bioinformatik und Molekulare Botanik, AG Bakteriengenetik , Friedrich-Schiller-Universität Jena , Jena , Germany
| | - Sabine Brantl
- a Matthias-Schleiden-Institut für Genetik, Bioinformatik und Molekulare Botanik, AG Bakteriengenetik , Friedrich-Schiller-Universität Jena , Jena , Germany
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Song T, Wang F, Xiong S, Jiang H. Surface display of organophosphorus-degrading enzymes on the recombinant spore of Bacillus subtilis. Biochem Biophys Res Commun 2019; 510:13-19. [PMID: 30660365 DOI: 10.1016/j.bbrc.2018.12.077] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 12/11/2018] [Indexed: 12/17/2022]
Abstract
Organophosphorus-degrading enzymes show high hydrolysis efficiency and provide an environmentally friendly solution to the pollution of organophosphorus compound. However, poor enzyme stability and tedious purification process have limited practical applications. Spore-based display system can provide many advantages, such as safety, low cost, easy preparation and high resistance to harsh conditions. Recently, we have constituted the recombinant spore displaying organophosphorus hydrolase and organophosphorus acid anhydrolase. In the spore display systems, recombinant spores could be reliably produced and normal sporulation was not affected; the activities of recombinant spores were 15.81 and 10.67 U/mg spores (dry weight) respectively; furthermore, the recombinant spores exhibited significantly enhanced resistance to various harsh conditions compared to free-form enzymes. These results indicated that the spore display could contribute to the practical application of organophosphorus-degrading enzymes and provide a promising solution to bioremediation of organophosphorus compounds.
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Affiliation(s)
- Tianyu Song
- Research Institute of Chemical Defense, Academy of Military Sciences, Beijing, 102205, PR China; State Key Laboratory of NBC Protection for Civilian, Academy of Military Sciences, Beijing, 102205, PR China
| | - Fuli Wang
- State Key Laboratory of NBC Protection for Civilian, Academy of Military Sciences, Beijing, 102205, PR China
| | - Shanshan Xiong
- Research Institute of Chemical Defense, Academy of Military Sciences, Beijing, 102205, PR China; State Key Laboratory of NBC Protection for Civilian, Academy of Military Sciences, Beijing, 102205, PR China
| | - Hui Jiang
- Research Institute of Chemical Defense, Academy of Military Sciences, Beijing, 102205, PR China; State Key Laboratory of NBC Protection for Civilian, Academy of Military Sciences, Beijing, 102205, PR China.
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J. Thiele M, Davari MD, König M, Hofmann I, Junker NO, Mirzaei Garakani T, Vojcic L, Fitter J, Schwaneberg U. Enzyme–Polyelectrolyte Complexes Boost the Catalytic Performance of Enzymes. ACS Catal 2018. [DOI: 10.1021/acscatal.8b02935] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Martin J. Thiele
- Institute of Biotechnology, RWTH Aachen University, Worringerweg 3, 52074 Aachen, Germany
| | - Mehdi D. Davari
- Institute of Biotechnology, RWTH Aachen University, Worringerweg 3, 52074 Aachen, Germany
| | - Melanie König
- Institute of Biotechnology, RWTH Aachen University, Worringerweg 3, 52074 Aachen, Germany
| | - Isabell Hofmann
- Institute of Biotechnology, RWTH Aachen University, Worringerweg 3, 52074 Aachen, Germany
| | - Niklas O. Junker
- I. Physikalisches Institut (IA), AG Biophysik, RWTH Aachen, Sommerfeldstrasse 14, 52074 Aachen, Germany
| | | | - Ljubica Vojcic
- Institute of Biotechnology, RWTH Aachen University, Worringerweg 3, 52074 Aachen, Germany
- Codexis, Inc., 200 Penobscot Drive, Redwood City, California 94063, United States
| | - Jörg Fitter
- I. Physikalisches Institut (IA), AG Biophysik, RWTH Aachen, Sommerfeldstrasse 14, 52074 Aachen, Germany
- Institute of Complex Systems (ICS-5): Molecular Biophysics, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Ulrich Schwaneberg
- Institute of Biotechnology, RWTH Aachen University, Worringerweg 3, 52074 Aachen, Germany
- DWI-Leibniz Institut für Interaktive Materialien, Forckenbeckstraße 50, 52056 Aachen, Germany
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Stress-Induced, Highly Efficient, Donor Cell-Dependent Cell-to-Cell Natural Transformation in Bacillus subtilis. J Bacteriol 2018; 200:JB.00267-18. [PMID: 29941421 DOI: 10.1128/jb.00267-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 06/14/2018] [Indexed: 11/20/2022] Open
Abstract
Horizontal gene transfer (HGT) is a driving force for bacterial evolution that occurs via conjugation, transduction, and transformation. Whereas conjugation and transduction depend on nonbacterial vehicles, transformation is considered a naturally occurring process in which naked DNA molecules are taken up by a competent recipient cell. Here, we report that HGT occurred between two Bacillus subtilis strains cocultured on a minimum medium agar plate for 10 h. This process was almost completely resistant to DNase treatment and appeared to require close proximity between cells. The deletion of comK in the recipient completely abolished gene transfer, indicating that the process involved transformation. This process was also highly efficient, reaching 1.75 × 106 transformants/μg DNA compared to 5.3 × 103 and 1.86 × 105 transformants/μg DNA for DNA-to-cell transformation by the same agar method and the standard two-step procedure, respectively. Interestingly, when three distantly localized chromosomal markers were selected simultaneously, the efficiency of cell-to-cell transformation still reached 6.26 × 104 transformants/μg DNA, whereas no transformants were obtained when free DNA was used as the donor. Stresses, such as starvation and exposure to antibiotics, further enhanced transformation efficiency by affecting the donor cells, suggesting that stress served as an important signal for promoting this type of HGT. Taken together, our results defined a bona fide process of cell-to-cell natural transformation (CTCNT) in B. subtilis and related species. This finding reveals the previously unrecognized role of donor cells in bacterial natural transformation and improves our understanding of how HGT drives bacterial evolution at a mechanistic level.IMPORTANCE Because DNA is easily prepared, studies of bacterial natural genetic transformation traditionally focus on recipient cells. However, such laboratory artifacts cannot explain how this process occurs in nature. In most cases, competence is only transient and involves approximately 20 to 50 genes, and it is unreasonable for bacteria to spend so many genetic resources on unpredictable and uncertain environmental DNA. Here, we characterized a donor cell-dependent CTCNT process in B. subtilis and related species that was almost completely resistant to DNase treatment and was more efficient than classical natural transformation using naked DNA as a donor, i.e., DNA-to-cell transformation, suggesting that DNA donor cells were also important in the transformation process in natural environments.
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Ye B, Zhou C, Zhao L, Cheng S, Cheng D, Yan X. Unmarked genetic manipulation in Bacillus subtilis by natural co-transformation. J Biotechnol 2018; 284:57-62. [PMID: 30092237 DOI: 10.1016/j.jbiotec.2018.08.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 07/27/2018] [Accepted: 08/05/2018] [Indexed: 01/14/2023]
Abstract
Bacillus subtilis is well known as both a model organism and as a microbial cell factory. Simple and scarless gene modification is a desirable tool for basic research and industrial applications of B. subtilis. It has been demonstrated that naturally competent strains of B. subtilis can uptake multiple different DNA molecules, a phenomenon called co-transformation. Here, we describe a co-transformation-based method for generating unmarked mutants of B. subtilis. The PCR product containing the desired mutant allele is introduced into B. subtilis through co-transformation of the plasmid pUS20, which harbours a spectinomycin-resistant marker (Spcr). The target mutation is acquired by screening transformants for integration of pUS20 by resistance to spectinomycin. Due to its unstable replication in B. subtilis, pUS20 is easily cured from transformants in the absence of spectinomycin. This method allows for point mutation delivery at frequencies of approximately 30%. Deletions and insertions of long DNA fragments can also be carried out efficiently using this method. Moreover, this method is also successful in Bacillus velezensis, indicating that it may be extended to other Bacillus species that can form natural competence.
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Affiliation(s)
- Bin Ye
- Jiangsu Provincial Key Lab for Solid Organic Wastes Utilization, Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, PR China
| | - Chaoyang Zhou
- Jiangsu Provincial Key Lab for Solid Organic Wastes Utilization, Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, PR China
| | - Leizhen Zhao
- Jiangsu Provincial Key Lab for Solid Organic Wastes Utilization, Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, PR China
| | - Shan Cheng
- Jiangsu Provincial Key Lab for Solid Organic Wastes Utilization, Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, PR China
| | - Dan Cheng
- Jiangsu Provincial Key Lab for Solid Organic Wastes Utilization, Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, PR China
| | - Xin Yan
- Jiangsu Provincial Key Lab for Solid Organic Wastes Utilization, 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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Reif C, Löser C, Brantl S. Bacillus subtilis Type I antitoxin SR6 Promotes Degradation of Toxin yonT mRNA and Is Required to Prevent Toxic yoyJ Overexpression. Toxins (Basel) 2018; 10:toxins10020074. [PMID: 29414903 PMCID: PMC5848175 DOI: 10.3390/toxins10020074] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 01/30/2018] [Accepted: 02/04/2018] [Indexed: 11/19/2022] Open
Abstract
yonT/SR6 is the second type I toxin-antitoxin (TA) system encoded on prophage SPβ in the B. subtilis chromosome. The yonT ORF specifying a 58 aa toxin is transcribed on a polycistronic mRNA under control of the yonT promoter. The antitoxin SR6 is a 100 nt antisense RNA that overlaps yonT at its 3′ end and the downstream gene yoyJ encoding a second, much weaker, toxin at its 5′ end. SR6 displays a half-life of >60 min, whereas yonT mRNA is less stable with a half-life of ≈8 min. SR6 is in significant excess over yonT mRNA except in minimal medium with glucose. It interacts with the 3′ UTR of yonT mRNA, thereby promoting its degradation by RNase III. By contrast, SR6 does not affect the amount or half-life of yoyJ mRNA. However, in its absence, a yoyJ overexpression plasmid could not be established in Bacillus subtilis suggesting that SR6 inhibits yoyJ translation by directly binding to its ribosome-binding site. While the amounts of both yonT RNA and SR6 were affected by vancomycin, manganese, heat-shock and ethanol stress as well as iron limitation, oxygen stress decreased only the amount of SR6.
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Affiliation(s)
- Celine Reif
- Friedrich-Schiller-Universität Jena, Lehrstuhl für Genetik, AG Bakteriengenetik, Philosophenweg 12, D-07743 Jena, Germany.
| | - Charlotte Löser
- Friedrich-Schiller-Universität Jena, Lehrstuhl für Genetik, AG Bakteriengenetik, Philosophenweg 12, D-07743 Jena, Germany.
| | - Sabine Brantl
- Friedrich-Schiller-Universität Jena, Lehrstuhl für Genetik, AG Bakteriengenetik, Philosophenweg 12, D-07743 Jena, Germany.
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Spacapan M, Danevčič T, Mandic-Mulec I. ComX-Induced Exoproteases Degrade ComX in Bacillus subtilis PS-216. Front Microbiol 2018; 9:105. [PMID: 29449835 PMCID: PMC5799266 DOI: 10.3389/fmicb.2018.00105] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 01/17/2018] [Indexed: 11/13/2022] Open
Abstract
Gram-positive bacteria use peptides as auto-inducing (AI) signals to regulate the production of extracellular enzymes (e.g., proteases). ComX is an AI peptide, mostly known for its role in the regulation of bacterial competence and surfactant production in Bacillus subtilis. These two traits are regulated accordingly to the bacterial population size, thus classifying ComX as a quorum sensing signal. ComX also indirectly regulates exoprotease production through the intermediate transcriptional regulator DegQ. We here use this peptide-based AI system (the ComQXPA system) as a model to address exoprotease regulation by ComX in biofilms. We also investigate the potential of ComX regulated proteases to degrade the ComX AI peptide. Results indicate that ComX indeed induces the expression of aprE, the gene for the major serine protease subtilisin, and stimulates overall exoprotease production in biofilms of B. subtilis PS-216 and several other B. subtilis soil isolates. We also provide evidence that these exoproteases can degrade ComX. The ComX biological activity decay is reduced in the spent media of floating biofilms with low proteolytic activity found in the comP and degQ mutants. ComX biological activity decay can be restored by the addition of subtilisin to such media. In contrast, inhibition of metalloproteases by EDTA reduces ComX biological activity decay. This suggests that both serine and metalloproteases, which are induced by ComX, are ultimately capable of degrading this signaling peptide. This work brings novel information on regulation of exoproteases in B. subtilis floating biofilms and reveals that these proteolytic enzymes degrade the AI signaling peptide ComX, which is also a major determinant of their expression in biofilms.
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Affiliation(s)
- Mihael Spacapan
- Chair of Microbiology, Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Tjaša Danevčič
- Chair of Microbiology, Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Ines Mandic-Mulec
- Chair of Microbiology, Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
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Cell surface engineering of Bacillus subtilis improves production yields of heterologously expressed α-amylases. Microb Cell Fact 2017; 16:56. [PMID: 28376879 PMCID: PMC5379735 DOI: 10.1186/s12934-017-0674-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 03/31/2017] [Indexed: 11/24/2022] Open
Abstract
Background Bacillus subtilis is widely used as a cell factory for numerous heterologous proteins of commercial value and medical interest. To explore the possibility of further enhancing the secretion potential of this model bacterium, a library of engineered strains with modified cell surface components was constructed, and the corresponding influences on protein secretion were investigated by analyzing the secretion of α-amylase variants with either low-, neutral- or high- isoelectric points (pI). Results Relative to the wild-type strain, the presence of overall anionic membrane phospholipids (phosphatidylglycerol and cardiolipin) increased dramatically in the PssA-, ClsA- and double KO mutants, which resulted in an up to 47% higher secretion of α-amylase. Additionally, we demonstrated that the appropriate net charge of secreted targets (AmyTS-23, AmyBs and AmyBm) was beneficial for secretion efficiency as well. Conclusions In B. subtilis, the characteristics of cell membrane phospholipid bilayer and the pIs of heterologous α-amylases appear to be important for their secretion efficiency. These two factors can be engineered to reduce the electrostatic interaction between each other during the secretion process, which finally leads to a better secretion yield of α-amylases.
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Zhu F, Yang X, Wu Y, Wang Y, Tang XF, Tang B. Release of an HtrA-Like Protease from the Cell Surface of Thermophilic Brevibacillus sp. WF146 via Substrate-Induced Autoprocessing of the N-terminal Membrane Anchor. Front Microbiol 2017; 8:481. [PMID: 28377763 PMCID: PMC5359297 DOI: 10.3389/fmicb.2017.00481] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Accepted: 03/08/2017] [Indexed: 01/07/2023] Open
Abstract
High-temperature requirement A (HtrA)-like proteases participate in protein quality control in prokaryotes and eukaryotes by degrading damaged proteins; however, little is known about HtrAs produced by thermophiles. HtrAw is an HtrA-like protease of thermophilic Brevibacillus sp. WF146. The intact form of HtrAw (iHtrAw) consisting of a transmembrane segment-containing N-terminal domain, a trypsin-like protease domain, and a C-terminal PDZ domain was produced in Escherichia coli. Purified iHtrAw itself is unable to cleave the N-terminal domain, but requires protein substrates to autoprocess the N-terminal domain intermolecularly, yielding a short form (sHtrAw). Mutation at the substrate-binding site in the PDZ domain affects the conversion of iHtrAw to sHtrAw. Deletion analysis revealed that the N-terminal domain is not necessary for enzyme folding, activity, and thermostability. Compared with other known HtrAs, HtrAw contains an additional Ca2+-binding Dx[DN]xDG motif important for enzyme stability and/or activity. When produced in an htrA/htrB double deletion mutant of Bacillus subtilis, iHtrAw localized predominantly to the cell pellet, and the amount of sHtrAw in the culture supernatant increased at elevated temperatures. Moreover, HtrAw increased the heat resistance of the B. subtilis mutant. In strain WF146, HtrAw exists in both a cell-associated intact form and a cell-free short form; an increase in growth temperature enhanced HtrAw production and the amount of cell-free short form. Release of the short form of HtrAw from the membrane may have the advantage of allowing the enzyme to freely access and degrade damaged proteins surrounding the bacterium living at high temperatures.
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Affiliation(s)
- Fengtao Zhu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University Wuhan, China
| | - Xing Yang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University Wuhan, China
| | - Yan Wu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University Wuhan, China
| | - Yasi Wang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University Wuhan, China
| | - Xiao-Feng Tang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan UniversityWuhan, China; Hubei Provincial Cooperative Innovation Center of Industrial FermentationWuhan, China
| | - Bing Tang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan UniversityWuhan, China; Hubei Provincial Cooperative Innovation Center of Industrial FermentationWuhan, China
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Simple and rapid direct cloning and heterologous expression of natural product biosynthetic gene cluster in Bacillus subtilis via Red/ET recombineering. Sci Rep 2016; 6:34623. [PMID: 27687863 PMCID: PMC5043344 DOI: 10.1038/srep34623] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 09/08/2016] [Indexed: 11/16/2022] Open
Abstract
Heterologous expression of biosynthetic pathways is an important way to research and discover microbial natural products. Bacillus subtilis is a suitable host for the heterologous production of natural products from bacilli and related Firmicutes. Existing technologies for heterologous expression of large biosynthetic gene clusters in B. subtilis are complicated. Herein, we present a simple and rapid strategy for direct cloning based heterologous expression of biosynthetic pathways in B. subtilis via Red/ET recombineering, using a 5.2 kb specific direct cloning vector carrying homologous sequences to the amyE gene in B. subtilis and CcdB counterselection marker. Using a two-step procedure, two large biosynthetic pathways for edeine (48.3 kb) and bacillomycin (37.2 kb) from Brevibacillus brevis X23 and B. amyloliquefaciens FZB42, respectively, were directly cloned and subsequently integrated into the chromosome of B. subtilis within one week. The gene cluster for bacillomycin was successfully expressed in the heterologous host, although edeine production was not detectable. Compared with similar technologies, this method offers a simpler and more feasible system for the discovery of natural products from bacilli and related genera.
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Toplak A, Nuijens T, Quaedflieg PJLM, Wu B, Janssen DB. Peptiligase, an Enzyme for Efficient Chemoenzymatic Peptide Synthesis and Cyclization in Water. Adv Synth Catal 2016. [DOI: 10.1002/adsc.201600017] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Ploss TN, Reilman E, Monteferrante CG, Denham EL, Piersma S, Lingner A, Vehmaanperä J, Lorenz P, van Dijl JM. Homogeneity and heterogeneity in amylase production by Bacillus subtilis under different growth conditions. Microb Cell Fact 2016; 15:57. [PMID: 27026185 PMCID: PMC4812647 DOI: 10.1186/s12934-016-0455-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 03/22/2016] [Indexed: 12/22/2022] Open
Abstract
Background Bacillus subtilis is an important cell factory for the biotechnological industry due to its ability to secrete commercially relevant proteins in large amounts directly into the growth medium. However, hyper-secretion of proteins, such as α-amylases, leads to induction of the secretion stress-responsive CssR-CssS regulatory system, resulting in up-regulation of the HtrA and HtrB proteases. These proteases degrade misfolded proteins secreted via the Sec pathway, resulting in a loss of product. The aim of this study was to investigate the secretion stress response in B. subtilis 168 cells overproducing the industrially relevant α-amylase AmyM from Geobacillus stearothermophilus, which was expressed from the strong promoter P(amyQ)-M. Results Here we show that activity of the htrB promoter as induced by overproduction of AmyM was “noisy”, which is indicative for heterogeneous activation of the secretion stress pathway. Plasmids were constructed to allow real-time analysis of P(amyQ)-M promoter activity and AmyM production by, respectively, transcriptional and out-of-frame translationally coupled fusions with gfpmut3. Our results show the emergence of distinct sub-populations of high- and low-level AmyM-producing cells, reflecting heterogeneity in the activity of P(amyQ)-M. This most likely explains the heterogeneous secretion stress response. Importantly, more homogenous cell populations with regard to P(amyQ)-M activity were observed for the B. subtilis mutant strain 168degUhy32, and the wild-type strain 168 under optimized growth conditions. Conclusion Expression heterogeneity of secretory proteins in B. subtilis can be suppressed by degU mutation and optimized growth conditions. Further, the out-of-frame translational fusion of a gene for a secreted target protein and gfp represents a versatile tool for real-time monitoring of protein production and opens novel avenues for Bacillus production strain improvement.
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Affiliation(s)
- Tina N Ploss
- AB Enzymes GmbH, Feldbergstrasse 78, 64293, Darmstadt, Germany
| | - Ewoud Reilman
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RD, Groningen, The Netherlands
| | - Carmine G Monteferrante
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RD, Groningen, The Netherlands.,Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Emma L Denham
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RD, Groningen, The Netherlands.,Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK
| | - Sjouke Piersma
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RD, Groningen, The Netherlands
| | - Anja Lingner
- AB Enzymes GmbH, Feldbergstrasse 78, 64293, Darmstadt, Germany.,c-LEcta GmbH, Perlickstraße 5, 04103, Leipzig, Germany
| | | | - Patrick Lorenz
- AB Enzymes GmbH, Feldbergstrasse 78, 64293, Darmstadt, Germany
| | - Jan Maarten van Dijl
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RD, Groningen, The Netherlands.
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Interplay of CodY and ScoC in the Regulation of Major Extracellular Protease Genes of Bacillus subtilis. J Bacteriol 2016; 198:907-20. [PMID: 26728191 DOI: 10.1128/jb.00894-15] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 12/24/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED AprE and NprE are two major extracellular proteases in Bacillus subtilis whose expression is directly regulated by several pleiotropic transcriptional factors, including AbrB, DegU, ScoC, and SinR. In cells growing in a rich, complex medium, the aprE and nprE genes are strongly expressed only during the post-exponential growth phase; mutations in genes encoding the known regulators affect the level of post-exponential-phase gene expression but do not permit high-level expression during the exponential growth phase. Using DNA-binding assays and expression and mutational analyses, we have shown that the genes for both exoproteases are also under strong, direct, negative control by the global transcriptional regulator CodY. However, because CodY also represses scoC, little or no derepression of aprE and nprE was seen in a codY null mutant due to overexpression of scoC. Thus, CodY is also an indirect positive regulator of these genes by limiting the synthesis of a second repressor. In addition, in cells growing under conditions that activate CodY, a scoC null mutation had little effect on aprE or nprE expression; full effects of scoC or codY null mutations could be seen only in the absence of the other regulator. However, even the codY scoC double mutant did not show high levels of aprE and nprE gene expression during exponential growth phase in a rich, complex medium. Only a third mutation, in abrB, allowed such expression. Thus, three repressors can contribute to reducing exoprotease gene expression during growth in the presence of excess nutrients. IMPORTANCE The major Bacillus subtilis exoproteases, AprE and NprE, are important metabolic enzymes whose genes are subject to complex regulation by multiple transcription factors. We show here that expression of the aprE and nprE genes is also controlled, both directly and indirectly, by CodY, a global transcriptional regulator that responds to the intracellular pools of amino acids. Direct CodY-mediated repression explains a long-standing puzzle, that is, why exoproteases are not produced when cells are growing exponentially in a medium containing abundant quantities of proteins or their degradation products. Indirect regulation of aprE and nprE through CodY-mediated repression of the scoC gene, encoding another pleiotropic repressor, serves to maintain a significant level of repression of exoprotease genes when CodY loses activity.
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Maturation of Fibrinolytic Bacillopeptidase F Involves both Hetero- and Autocatalytic Processes. Appl Environ Microbiol 2015; 82:318-27. [PMID: 26497454 DOI: 10.1128/aem.02673-15] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 10/19/2015] [Indexed: 11/20/2022] Open
Abstract
Bacillopeptidase F (Bpr) is a fibrinolytic serine protease produced by Bacillus subtilis. Its precursor is composed of a signal peptide, an N-terminal propeptide, a catalytic domain, and a long C-terminal extension (CTE). Several active forms of Bpr have been previously reported, but little is known about the maturation of this enzyme. Here, a gene encoding a Bpr (BprL) was cloned from B. subtilis LZW and expressed in B. subtilis WB700, and three fibrinolytic mature forms with apparent molecular masses of 45, 75, and 85 kDa were identified in the culture supernatant. After treatment with urea, the 75-kDa mature form had the same molecular mass as the 85-kDa mature form, from which we infer that they adopt different conformations. Mutational analysis revealed that while the 85-kDa mature form is generated via heterocatalytic processing of a BprL proform by an unidentified protease of B. subtilis, the production of the 75- and 45-kDa mature forms involves both hetero- and autocatalytic events. From in vitro analysis of BprL and its sequential C-terminal truncation variants, it appears that partial removal of the CTE is required for the initiation of autoprocessing of the N-terminal propeptide, which is composed of a core domain (N*) and a 15-residue linker peptide, thereby yielding the 45-kDa mature form. These data suggest that the differential processing of BprL, either heterocatalytically or autocatalytically, leads to the formation of multiple mature forms with different molecular masses or conformations.
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Recruiting a new strategy to improve levan production in Bacillus amyloliquefaciens. Sci Rep 2015; 5:13814. [PMID: 26347185 PMCID: PMC4561895 DOI: 10.1038/srep13814] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 08/06/2015] [Indexed: 11/29/2022] Open
Abstract
Microbial levan is an important biopolymer with considerable potential in food and medical applications. Bacillus amyloliquefaciens NK-ΔLP strain can produce high-purity, low-molecular-weight levan, but production is relatively low. To enhance the production of levan, six extracellular protease genes (bpr, epr, mpr, vpr, nprE and aprE), together with the tasA gene (encoding the major biofilm matrix protein TasA) and the pgsBCA cluster (responsible for poly-γ-glutamic acid (γ-PGA) synthesis), were intentionally knocked out in the Bacillus amyloliquefaciens NK-1 strain. The highest levan production (31.1 g/L) was obtained from the NK-Q-7 strain (ΔtasA, Δbpr, Δepr, Δmpr, Δvpr, ΔnprE, ΔaprE and ΔpgsBCA), which was 103% higher than that of the NK-ΔLP strain (ΔpgsBCA) (15.3 g/L). Furthermore, the NK-Q-7 strain also showed a 94.1% increase in α-amylase production compared with NK-ΔLP strain, suggesting a positive effect of extracellular protease genes deficient on the production of endogenously secreted proteins. This is the first report of the improvement of levan production in microbes deficient in extracellular proteases and TasA, and the NK-Q-7 strain exhibits outstanding characteristics for extracellular protein production or extracellular protein related product synthesis.
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Disulfide Bonds of Proteins Displayed on Spores of Bacillus subtilis Can Occur Spontaneously. Curr Microbiol 2015; 71:156-61. [DOI: 10.1007/s00284-015-0839-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 04/24/2015] [Indexed: 10/23/2022]
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CodY regulates expression of the Bacillus subtilis extracellular proteases Vpr and Mpr. J Bacteriol 2015; 197:1423-32. [PMID: 25666135 DOI: 10.1128/jb.02588-14] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
UNLABELLED CodY is a global transcriptional regulator in low-G+C Gram-positive bacteria that is responsive to GTP and branched-chain amino acids. By interacting with its two cofactors, it is able to sense the nutritional and energetic status of the cell and respond by regulating expression of adaptive genetic programs. In Bacillus subtilis, more than 200 genes, including those for peptide transporters, intracellular proteolytic enzymes, and amino acid degradative pathways, are controlled by CodY. In this study, we demonstrated that expression of two extracellular proteases, Vpr and Mpr, is negatively controlled by CodY. By gel mobility shift and DNase I footprinting assays, we showed that CodY binds to the regulatory regions of both genes, in the vicinity of their transcription start points. The mpr gene is also characterized by the presence of a second, higher-affinity CodY-binding site located at the beginning of its coding sequence. Using strains carrying vpr- or mpr-lacZ transcriptional fusions in which CodY-binding sites were mutated, we demonstrated that repression of both protease genes is due to the direct effect by CodY and that the mpr internal site is required for regulation. The vpr promoter is a rare example of a sigma H-dependent promoter that is regulated by CodY. In a codY null mutant, Vpr became one of the more abundant proteins of the B. subtilis exoproteome. IMPORTANCE CodY is a global transcriptional regulator of metabolism and virulence in low-G+C Gram-positive bacteria. In B. subtilis, more than 200 genes, including those for peptide transporters, intracellular proteolytic enzymes, and amino acid degradative pathways, are controlled by CodY. However, no role for B. subtilis CodY in regulating expression of extracellular proteases has been established to date. In this work, we demonstrate that by binding to the regulatory regions of the corresponding genes, B. subtilis CodY negatively controls expression of Vpr and Mpr, two extracellular proteases. Thus, in B. subtilis, CodY can now be seen to regulate the entire protein utilization pathway.
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Jeong DE, Park SH, Pan JG, Kim EJ, Choi SK. Genome engineering using a synthetic gene circuit in Bacillus subtilis. Nucleic Acids Res 2014; 43:e42. [PMID: 25552415 PMCID: PMC4381049 DOI: 10.1093/nar/gku1380] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Accepted: 12/19/2014] [Indexed: 11/16/2022] Open
Abstract
Genome engineering without leaving foreign DNA behind requires an efficient counter-selectable marker system. Here, we developed a genome engineering method in Bacillus subtilis using a synthetic gene circuit as a counter-selectable marker system. The system contained two repressible promoters (B. subtilis xylA (Pxyl) and spac (Pspac)) and two repressor genes (lacI and xylR). Pxyl-lacI was integrated into the B. subtilis genome with a target gene containing a desired mutation. The xylR and Pspac–chloramphenicol resistant genes (cat) were located on a helper plasmid. In the presence of xylose, repression of XylR by xylose induced LacI expression, the LacIs repressed the Pspac promoter and the cells become chloramphenicol sensitive. Thus, to survive in the presence of chloramphenicol, the cell must delete Pxyl-lacI by recombination between the wild-type and mutated target genes. The recombination leads to mutation of the target gene. The remaining helper plasmid was removed easily under the chloramphenicol absent condition. In this study, we showed base insertion, deletion and point mutation of the B. subtilis genome without leaving any foreign DNA behind. Additionally, we successfully deleted a 2-kb gene (amyE) and a 38-kb operon (ppsABCDE). This method will be useful to construct designer Bacillus strains for various industrial applications.
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Affiliation(s)
- Da-Eun Jeong
- Super-Bacteria Research Center, KRIBB, 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806, Republic of Korea
| | - Seung-Hwan Park
- Super-Bacteria Research Center, KRIBB, 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806, Republic of Korea Biosystems and Bioengineering Program, University of Science and Technology (UST), 217 Gajung-ro, Yuseong-gu, Daejeon 305-350, Republic of Korea
| | - Jae-Gu Pan
- Super-Bacteria Research Center, KRIBB, 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806, Republic of Korea
| | - Eui-Joong Kim
- Genofocus Inc., 533-1 Yongsan-dong, Yuseong-gu, Daejeon 305-500, Republic of Korea
| | - Soo-Keun Choi
- Super-Bacteria Research Center, KRIBB, 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806, Republic of Korea Biosystems and Bioengineering Program, University of Science and Technology (UST), 217 Gajung-ro, Yuseong-gu, Daejeon 305-350, Republic of Korea
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The two putative comS homologs of the biotechnologically important Bacillus licheniformis do not contribute to competence development. Appl Microbiol Biotechnol 2014; 99:2255-66. [PMID: 25520171 DOI: 10.1007/s00253-014-6291-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 11/28/2014] [Accepted: 12/02/2014] [Indexed: 01/17/2023]
Abstract
In Bacillus subtilis, natural genetic competence is subject to complex genetic regulation and quorum sensing dependent. Upon extracellular accumulation of the peptide-pheromone ComX, the membrane-bound sensor histidine kinase ComP initiates diverse signaling pathways by activating-among others-DegQ and ComS. While DegQ favors the expression of extracellular enzymes rather than competence development, ComS is crucial for competence development as it prevents proteolytic degradation of ComK, the key transcriptional activator of all genes required for the uptake and integration of DNA. In Bacillus licheniformis, ComX/ComP sensed cell density negatively influences competence development, suggesting differences from the quorum-sensing-dependent control mechanism in Bacillus subtilis. Here, we show that each of six investigated strains possesses both of two different, recently identified putative comS genes. When expressed from an inducible promoter, none of the comS candidate genes displayed an impact on competence development neither in B. subtilis nor in B. licheniformis. Moreover, disruption of the genes did not reduce transformation efficiency. While the putative comS homologs do not contribute to competence development, we provide evidence that the degQ gene as for B. subtilis negatively influences genetic competency in B. licheniformis.
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Pan JG, Choi SK, Jung HC, Kim EJ. Display of native proteins on Bacillus subtilis spores. FEMS Microbiol Lett 2014; 358:209-17. [PMID: 25168353 DOI: 10.1111/1574-6968.12558] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2014] [Revised: 07/29/2014] [Accepted: 07/30/2014] [Indexed: 01/07/2023] Open
Abstract
In principle, protein display is enabled by fusing target proteins to naturally secreted, surface-anchored protein motifs. In this work, we developed a method of native protein display on the Bacillus spore surface that obviates the need to construct fusion proteins to display a motif. Spore coat proteins are expressed in the mother cell compartment and are subsequently assembled and deposited on the surface of spores. Therefore, target proteins overexpressed in the mother cell compartment during the late sporulation phase were expected to be targeted and displayed on the spore surface. As a proof of principle, we demonstrated the display of carboxymethylcellulase (CMCase) in its native form on the spore surface. The target protein, CMCase, was expressed under the control of the cry1Aa promoter, which is controlled by σ(E) and σ(K) and is expressed in the mother cell compartment. The correct display was confirmed using enzyme activity assays, flow cytometry, and immunogold electron microscopy. In addition, we demonstrated the display of a β-galactosidase tetramer and confirmed its correct display using enzyme activity assays and protein characterization. This native protein display system, combined with the robust nature of Bacillus spores, will broaden the range of displayable target proteins. Consequently, the applications of display technology will be expanded, including high-throughput screening, vaccines, biosensors, biocatalysis, bioremediation, and other innovative bioprocesses.
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Affiliation(s)
- Jae-Gu Pan
- Superbacteria Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea
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50
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Suwanmanon K, Hsieh PC. Effect of γ-aminobutyric acid and nattokinase-enriched fermented beans on the blood pressure of spontaneously hypertensive and normotensive Wistar-Kyoto rats. J Food Drug Anal 2014; 22:485-491. [PMID: 28911464 PMCID: PMC9354997 DOI: 10.1016/j.jfda.2014.03.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 03/05/2014] [Accepted: 03/07/2014] [Indexed: 11/26/2022] Open
Abstract
In this study we have evaluated the changes in arterial blood pressure in spontaneously hypertensive rats (SHR) caused by the short-term intake of Bacillus subtilis B060-fermented beans with significant γ-aminobutyric acid (GABA) and nattokinase activity. After being weaned, 7-week-old male SHR and 7-week-old male Wistar–Kyoto (WKY) rats were randomized into seven groups. Until the 8th week of life, the rats in each group were given one of the following: Group 1, high dose of GABA and nattokinase in the SHR (SHD); Group 2, medium dose of GABA and nattokinase in the SHR (SMD); Group 3, low dose of GABA and nattokinase in the SHR (SLD); Group 4, negative control in the SHR (SD); Group 5, positive control in the SHR (SM); Group 6, high dose of GABA and nattokinase in the WKY (WHD); and Group 7, negative control in the WKY (WD). Distilled water served as the negative control, and captopril (50 mg/kg), a known ACE inhibitor, served as the positive control. Systolic blood pressure and diastolic blood pressure values were measured weekly from the 8th week to the 16th week of life using the tail-cuff method. A definite decrease in systolic and diastolic blood pressure values could be observed in the rats treated with captopril and in the rats that received GABA and nattokinase. The greatest antihypertensive effect was observed when the pharmacological treatment was administered. The effect of the daily intake of fermented beans containing GABA and nattokinase may be helpful in controlling blood pressure levels in hypertensive model animals. The fermentation of beans with B. subtilis B060 may therefore constitute a successful strategy for producing a functional food with antihypertensive activity.
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Affiliation(s)
- Kanintra Suwanmanon
- Department of Tropical Agriculture and International Cooperation, National Pingtung University of Science and Technology, Pingtung, Taiwan.
| | - Pao-Chuan Hsieh
- Department of Food Science, National Pingtung University of Science and Technology, Pingtung, Taiwan
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