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Recent advances in genetic tools for engineering probiotic lactic acid bacteria. Biosci Rep 2023; 43:232386. [PMID: 36597861 PMCID: PMC9842951 DOI: 10.1042/bsr20211299] [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] [Received: 09/08/2022] [Revised: 12/19/2022] [Accepted: 01/03/2023] [Indexed: 01/05/2023] Open
Abstract
Synthetic biology has grown exponentially in the last few years, with a variety of biological applications. One of the emerging applications of synthetic biology is to exploit the link between microorganisms, biologics, and human health. To exploit this link, it is critical to select effective synthetic biology tools for use in appropriate microorganisms that would address unmet needs in human health through the development of new game-changing applications and by complementing existing technological capabilities. Lactic acid bacteria (LAB) are considered appropriate chassis organisms that can be genetically engineered for therapeutic and industrial applications. Here, we have reviewed comprehensively various synthetic biology techniques for engineering probiotic LAB strains, such as clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 mediated genome editing, homologous recombination, and recombineering. In addition, we also discussed heterologous protein expression systems used in engineering probiotic LAB. By combining computational biology with genetic engineering, there is a lot of potential to develop next-generation synthetic LAB with capabilities to address bottlenecks in industrial scale-up and complex biologics production. Recently, we started working on Lactochassis project where we aim to develop next generation synthetic LAB for biomedical application.
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Biswas S, Keightley A, Biswas I. Characterization of a stress tolerance-defective mutant of Lactobacillus rhamnosus LRB. Mol Oral Microbiol 2019; 34:153-167. [PMID: 31056830 DOI: 10.1111/omi.12262] [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: 03/15/2019] [Revised: 04/25/2019] [Accepted: 04/26/2019] [Indexed: 02/06/2023]
Abstract
Lactobacillus rhamnosus is a lactic acid bacterium that survives diverse ecological niches, including the human oral cavity and gastrointestinal tract. L. rhamnosus is an acidogenic bacterium that produces copious amounts of lactic acid. The organism is also considered as aciduric, since it can survive prolonged exposure to an acidic environment. For a probiotic bacterium such as L. rhamnosus, it is necessary to understand how this organism survives acid stress. In this study we used L. rhamnosus LRB to isolate one spontaneous mutant that was sensitive to acid stress. The mutant, which we named RBM1, also displayed sensitivity to a wide range of stresses including osmotic, thermal, and others. Using whole genome sequencing, we mapped the putative mutations in the mutant strain. It appears that three single nucleotide substitutions occurred in the mutant as compared to the wild-type LRB strain. Among those, the most relevant mutation occurred in the ftsH gene that created a single amino acid change in the protein. We performed a comparative proteomic study to understand the molecular basis for stress sensitivity and found that ~15% of the proteome is altered in the mutant strain. Our study suggests that generation of spontaneous mutants during L. rhamnosus colonization could drastically affect bacterial physiology and survival under stress conditions.
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Affiliation(s)
- Saswati Biswas
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas, Medical Center, Kansas City, Kansas
| | - Andrew Keightley
- Mass Spectrometry and Proteomics, UMKC School of Biological Sciences, Kansas City, Missouri
| | - Indranil Biswas
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas, Medical Center, Kansas City, Kansas
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Transposition of IS 4 Family Insertion Sequences IS Teha3, IS Teha4, and IS Teha5 into the arc Operon Disrupts Arginine Deiminase System in Tetragenococcus halophilus. Appl Environ Microbiol 2019; 85:AEM.00208-19. [PMID: 30877114 DOI: 10.1128/aem.00208-19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 03/11/2019] [Indexed: 01/10/2023] Open
Abstract
Tetragenococcus halophilus, a halophilic lactic acid bacterium, is often used as a starter culture in the manufacturing of soy sauce. T. halophilus possesses an arginine deiminase system, which is responsible for the accumulation of citrulline, the main precursor of the potential carcinogen ethyl carbamate. In this study, we generated five derivatives lacking arginine deiminase activity from T. halophilus NBRC 12172 by UV irradiation. Using these derivatives as a fermentation starter prevented arginine deimination in soy sauce. DNA sequence analysis of the derivatives revealed that novel IS4 family insertion sequences, designated ISTeha3, ISTeha4, and ISTeha5, were transposed into the region around the arginine deiminase (arc) operon in the mutants. These insertion sequences contain a single open reading frame encoding a putative transposase and 13- to 15-bp inverted repeats at both termini, which are adjacent to 7- to 9-bp duplications of the target sequence. Investigation of wild strains isolated from soy sauce mash incapable of arginine deimination also indicated that insertion sequences are involved in the disruption of the arginine deiminase system in T. halophilus IMPORTANCE Insertion sequences play important roles in bacterial evolution and are frequently utilized in mutagenesis systems. However, the intrinsic insertion sequences of tetragenococci are not well characterized. Here, we identified three active insertion sequences of T. halophilus by transposition into the region around the arc operon. This report provides an example of insertion sequence-mediated generation and evolution of T. halophilus and primary information about their characteristics.
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Matos RC, Schwarzer M, Gervais H, Courtin P, Joncour P, Gillet B, Ma D, Bulteau AL, Martino ME, Hughes S, Chapot-Chartier MP, Leulier F. D-Alanylation of teichoic acids contributes to Lactobacillus plantarum-mediated Drosophila growth during chronic undernutrition. Nat Microbiol 2017; 2:1635-1647. [PMID: 28993620 PMCID: PMC5706638 DOI: 10.1038/s41564-017-0038-x] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 09/06/2017] [Indexed: 02/07/2023]
Abstract
The microbial environment influences animal physiology. However, the underlying molecular mechanisms of such functional interactions are largely undefined. Previously, we showed that during chronic undernutrition, strains of Lactobacillus plantarum, a major commensal partner of Drosophila, promote host juvenile growth and maturation partly through enhanced expression of intestinal peptidases. By screening a transposon insertion library of Lactobacillus plantarum in gnotobiotic Drosophila larvae, we identify a bacterial cell-wall-modifying machinery encoded by the pbpX2-dlt operon that is critical to enhance host digestive capabilities and promote animal growth and maturation. Deletion of this operon leads to bacterial cell wall alteration with a complete loss of D-alanylation of teichoic acids. We show that L. plantarum cell walls bearing D-alanylated teichoic acids are directly sensed by Drosophila enterocytes to ensure optimal intestinal peptidase expression and activity, juvenile growth and maturation during chronic undernutrition. We thus conclude that besides peptidoglycan, teichoic acid modifications participate in the host-commensal bacteria molecular dialogue occurring in the intestine.
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Affiliation(s)
- Renata C Matos
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, 69364, Lyon Cedex 07, France
| | - Martin Schwarzer
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, 69364, Lyon Cedex 07, France
| | - Hugo Gervais
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, 69364, Lyon Cedex 07, France
| | - Pascal Courtin
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Pauline Joncour
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, 69364, Lyon Cedex 07, France
| | - Benjamin Gillet
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, 69364, Lyon Cedex 07, France
| | - Dali Ma
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, 69364, Lyon Cedex 07, France
| | - Anne-Laure Bulteau
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, 69364, Lyon Cedex 07, France
| | - Maria Elena Martino
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, 69364, Lyon Cedex 07, France
| | - Sandrine Hughes
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, 69364, Lyon Cedex 07, France
| | | | - François Leulier
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, 69364, Lyon Cedex 07, France.
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Granato LM, Picchi SC, Andrade MDO, Takita MA, de Souza AA, Wang N, Machado MA. The ATP-dependent RNA helicase HrpB plays an important role in motility and biofilm formation in Xanthomonas citri subsp. citri. BMC Microbiol 2016; 16:55. [PMID: 27005008 PMCID: PMC4804567 DOI: 10.1186/s12866-016-0655-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 03/02/2016] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND RNA helicases are enzymes that catalyze the separation of double-stranded RNA (dsRNA) using the free energy of ATP binding and hydrolysis. DEAD/DEAH families participate in many different aspects of RNA metabolism, including RNA synthesis, RNA folding, RNA-RNA interactions, RNA localization and RNA degradation. Several important bacterial DEAD/DEAH-box RNA helicases have been extensively studied. In this study, we characterize the ATP-dependent RNA helicase encoded by the hrpB (XAC0293) gene using deletion and genetic complementation assays. We provide insights into the function of the hrpB gene in Xanthomonas citri subsp. citri by investigating the roles of hrpB in biofilm formation on abiotic surfaces and host leaves, cell motility, host virulence of the citrus canker bacterium and growth in planta. RESULTS The hrpB gene is highly conserved in the sequenced strains of Xanthomonas. Mutation of the hrpB gene (∆hrpB) resulted in a significant reduction in biofilms on abiotic surfaces and host leaves. ∆hrpB also exhibited increased cell dispersion on solid medium plates. ∆hrpB showed reduced adhesion on biotic and abiotic surfaces and delayed development in disease symptoms when sprayed on susceptible citrus leaves. Quantitative reverse transcription-PCR assays indicated that deletion of hrpB reduced the expression of four type IV pili genes. The transcriptional start site of fimA (XAC3241) was determined using rapid amplification of 5'-cDNA Ends (5'RACE). Based on the results of fimA mRNA structure predictions, the fimA 5' UTR may contain three different loops. HrpB may be involved in alterations to the structure of fimA mRNA that promote the stability of fimA RNA. CONCLUSIONS Our data show that hrpB is involved in adherence of Xanthomonas citri subsp. citri to different surfaces. In addition, to the best of our knowledge, this is the first time that a DEAH RNA helicase has been implicated in the regulation of type IV pili in Xanthomonas.
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Affiliation(s)
- Laís Moreira Granato
- Centro de Citricultura Sylvio Moreira/IAC, Rodovia Anhanguera Km 158, Cordeirópolis, SP, 13490-970, Brazil
- Universidade Estadual de Campinas/UNICAMP, Instituto de Biologia, P.O. Box 6010, Campinas, SP, 13083-970, Brazil
| | - Simone Cristina Picchi
- Centro de Citricultura Sylvio Moreira/IAC, Rodovia Anhanguera Km 158, Cordeirópolis, SP, 13490-970, Brazil
| | - Maxuel de Oliveira Andrade
- Citrus Research and Educational Center, Department of Microbiology and Cell Science, University of Florida, IFAS, 700 Experiment Station Road, Lake Alfred, FL, 33850, USA
| | - Marco Aurélio Takita
- Centro de Citricultura Sylvio Moreira/IAC, Rodovia Anhanguera Km 158, Cordeirópolis, SP, 13490-970, Brazil
| | - Alessandra Alves de Souza
- Centro de Citricultura Sylvio Moreira/IAC, Rodovia Anhanguera Km 158, Cordeirópolis, SP, 13490-970, Brazil
| | - Nian Wang
- Citrus Research and Educational Center, Department of Microbiology and Cell Science, University of Florida, IFAS, 700 Experiment Station Road, Lake Alfred, FL, 33850, USA
| | - Marcos Antonio Machado
- Centro de Citricultura Sylvio Moreira/IAC, Rodovia Anhanguera Km 158, Cordeirópolis, SP, 13490-970, Brazil.
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Khemici V, Linder P. RNA helicases in bacteria. Curr Opin Microbiol 2016; 30:58-66. [PMID: 26808656 DOI: 10.1016/j.mib.2016.01.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 01/06/2016] [Indexed: 11/18/2022]
Abstract
RNA plays a crucial role in the control of bacterial gene expression, either as carrier of information or as positive or negative regulators. Moreover, the machinery to decode the information, the ribosome, is a large ribonucleoprotein complex composed of rRNAs and many proteins. RNAs are normally single stranded but have the propensity to fold into secondary structures or anneal each other. In some instances these interactions are beneficial for the function of the RNA, but in other cases they may be deleterious. All cells have therefore developed proteins that act as chaperones or helicases to keep RNA metabolism alive.
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Affiliation(s)
- Vanessa Khemici
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, 1, rue Michel Servet, 1211 Geneva 4, Switzerland
| | - Patrick Linder
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, 1, rue Michel Servet, 1211 Geneva 4, Switzerland.
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Redder P, Hausmann S, Khemici V, Yasrebi H, Linder P. Bacterial versatility requires DEAD-box RNA helicases. FEMS Microbiol Rev 2015; 39:392-412. [PMID: 25907111 DOI: 10.1093/femsre/fuv011] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/04/2015] [Indexed: 11/13/2022] Open
Abstract
RNA helicases of the DEAD-box and DEAH-box families are important players in many processes involving RNA molecules. These proteins can modify RNA secondary structures or intermolecular RNA interactions and modulate RNA-protein complexes. In bacteria, they are known to be involved in ribosome biogenesis, RNA turnover and translation initiation. They thereby play an important role in the adaptation of bacteria to changing environments and to respond to stress conditions.
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Affiliation(s)
- Peter Redder
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, 1, rue Michel Servet, CH 1211 Geneva 4, Switzerland
| | - Stéphane Hausmann
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, 1, rue Michel Servet, CH 1211 Geneva 4, Switzerland
| | - Vanessa Khemici
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, 1, rue Michel Servet, CH 1211 Geneva 4, Switzerland
| | - Haleh Yasrebi
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, 1, rue Michel Servet, CH 1211 Geneva 4, Switzerland
| | - Patrick Linder
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, 1, rue Michel Servet, CH 1211 Geneva 4, Switzerland
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8
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Identification of a proton-chloride antiporter (EriC) by Himar1 transposon mutagenesis in Lactobacillus reuteri and its role in histamine production. Antonie van Leeuwenhoek 2014; 105:579-92. [PMID: 24488273 DOI: 10.1007/s10482-014-0113-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 01/01/2014] [Indexed: 12/21/2022]
Abstract
The gut microbiome may modulate intestinal immunity by luminal conversion of dietary amino acids to biologically active signals. The model probiotic organism Lactobacillus reuteri ATCC PTA 6475 is indigenous to the human microbiome, and converts the amino acid L-histidine to the biogenic amine, histamine. Histamine suppresses tumor necrosis factor (TNF) production by human myeloid cells and is a product of L-histidine decarboxylation, which is a proton-facilitated reaction. A transposon mutagenesis strategy was developed based on a single-plasmid nisin-inducible Himar1 transposase/transposon delivery system for L. reuteri. A highly conserved proton-chloride antiporter gene (eriC), a gene widely present in the gut microbiome was discovered by Himar1 transposon (Tn)-mutagenesis presented in this study. Genetic inactivation of eriC by transposon insertion and genetic recombineering resulted in reduced ability of L. reuteri to inhibit TNF production by activated human myeloid cells, diminished histamine production by the bacteria and downregulated expression of histidine decarboxylase cluster genes compared to those of WT 6475. EriC belongs to a large family of ion transporters that includes chloride channels and proton-chloride antiporters and may facilitate the availability of protons for the decarboxylation reaction, resulting in histamine production by L. reuteri. This report leverages the tools of bacterial genetics for probiotic gene discovery. The findings highlight the widely conserved nature of ion transporters in bacteria and how ion transporters are coupled with amino acid decarboxylation and contribute to microbiome-mediated immunomodulation.
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Oun S, Redder P, Didier JP, François P, Corvaglia AR, Buttazzoni E, Giraud C, Girard M, Schrenzel J, Linder P. The CshA DEAD-box RNA helicase is important for quorum sensing control in Staphylococcus aureus. RNA Biol 2012; 10:157-65. [PMID: 23229022 PMCID: PMC3590232 DOI: 10.4161/rna.22899] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
DEAD-box RNA helicases are present in almost all living organisms and participate in various processes of RNA metabolism. Bacterial proteins of this large family were shown to be required for translation initiation, ribosome biogenesis and RNA decay. The latter is primordial for rapid adaptation to changing environmental conditions. In particular, the RhlB RNA helicase from E. coli was shown to assist the bacterial degradosome machinery. Recently, the CshA DEAD-box proteins from Bacillus subtilis and Staphylococcus aureus were shown to interact with proteins that are believed to form the degradosome. S. aureus can cause life-threatening disease, with particular concern focusing on biofilm formation on catheters and prosthetic devices, since in this form the bacteria are almost impossible to eradicate both by the immune system and antibiotic treatment. This persistent state relies on the expression of surface encoded proteins that allow attachment to various surfaces, and contrasts with the dispersal mode of growth that relies on the secretion of proteins such as hemolysins and proteases. The switch between these two states is mainly mediated by the Staphylococcal cell density sensing system encoded by agr. We show that inactivation of the cshA DEAD-box gene results in dysregulation of biofilm formation and hemolysis through modulation of agr mRNA stability. Importantly, inactivation of the agrA gene in the cshA mutant background reverses the defect, indicating that cshA is genetically upstream of agr and that a delicate balance of agr mRNA abundance mediated through stability control by CshA is critical for proper expression of virulence factors.
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Affiliation(s)
- Stella Oun
- Department of Microbiology and Molecular Medicine, CMU, Medical Faculty, University of Geneva, Genève, Switzerland
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Development of an efficient in vivo system (Pjunc-TpaseIS1223) for random transposon mutagenesis of Lactobacillus casei. Appl Environ Microbiol 2012; 78:5417-23. [PMID: 22610425 DOI: 10.1128/aem.00531-12] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The random transposon mutagenesis system P(junc)-TpaseIS(1223) is composed of plasmids pVI129, expressing IS1223 transposase, and pVI110, a suicide transposon plasmid carrying the P(junc) sequence, the substrate of the IS1223 transposase. This system is particularly efficient in Lactobacillus casei, as more than 10,000 stable, random mutants were routinely obtained via electroporation.
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Abstract
DEAD-box RNA helicases are important players in eukaryotic and bacterial RNA metabolism. A helicase from Staphylococcus aureus was recently shown to affect RNA decay, most likely via its interaction with the proposed Gram-positive degradosome. Some, but not all, RNAs are stabilized when the helicase CshA is mutated, and among the affected RNAs is the agrBDCA mRNA, which is responsible for quorum sensing in S. aureus. We describe how the stabilization of agr mRNA (and others) can be measured and how to conduct assays to measure the effects of quorum-sensing defects, such as biofilm formation and hemolysin production.
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Ito M, Kim YG, Tsuji H, Kiwaki M, Nomoto K, Tanaka R, Okada N, Danbara H. A practical random mutagenesis system for probiotic Lactobacillus casei using Tn5 transposition complexes. J Appl Microbiol 2010; 109:657-666. [PMID: 20202016 DOI: 10.1111/j.1365-2672.2010.04690.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS Despite the fact that the entire genome sequence of probiotic Lactobacillus casei has recently been available, their mechanisms of beneficial effects are poorly clarified, probably because of the lack of an efficient mutagenesis system. The aim of this study was to establish a practical random mutagenesis system of L. casei using the Tn5 transposome complexes. METHODS AND RESULTS We optimized the conditions for transformation using a plasmid pUCYIT356-1-Not2 and then transposition reaction using Tn5 transposome system for L. casei ATCC 27139. Tn5 insertion library of this strain being consisted of 9408 mutants was constructed by repeating the mutagenesis procedure. To examine the utility of this mutagenesis system, we screened a panel of insertion mutants for nutrient requirements. Six auxotrophic mutants were isolated and their Tn5 insertion sites were determined by inverse PCR, which demonstrated that insertions occur randomly throughout the whole bacterial genome. CONCLUSIONS Tn5 transposome system functioned efficiently to generate transposon insertion mutants of L. casei and enabled to construct useful L. casei Tn5 insertion library at optimized conditions for transformation and transposition. SIGNIFICANCE AND IMPACT OF THE STUDY The availability of this system facilitates the study of the mechanisms of beneficial effects of L. casei for human health.
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Affiliation(s)
- M Ito
- Department of Microbiology, School of Pharmacy, Kitasato University, Tokyo, Japan
| | - Y-G Kim
- Department of Microbiology, School of Pharmacy, Kitasato University, Tokyo, Japan
| | - H Tsuji
- Yakult Central Institute for Microbiological Research, Tokyo, Japan
| | - M Kiwaki
- Yakult Central Institute for Microbiological Research, Tokyo, Japan
| | - K Nomoto
- Yakult Central Institute for Microbiological Research, Tokyo, Japan
| | - R Tanaka
- Yakult Central Institute for Microbiological Research, Tokyo, Japan
| | - N Okada
- Department of Microbiology, School of Pharmacy, Kitasato University, Tokyo, Japan
| | - H Danbara
- Department of Microbiology, School of Pharmacy, Kitasato University, Tokyo, Japan
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