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Chamlagain B, Peltonen L, Edelmann M, Ramos-Diaz JM, Kemppinen A, Jouppila K, Varmanen P, Piironen V. Bioaccessibility of vitamin B12 synthesized by Propionibacterium freudenreichii and from products made with fermented wheat bran extract. Curr Res Food Sci 2021; 4:499-502. [PMID: 34382008 PMCID: PMC8340120 DOI: 10.1016/j.crfs.2021.07.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 07/23/2021] [Accepted: 07/23/2021] [Indexed: 12/29/2022] Open
Abstract
The bioaccessibility of vitamin B12 (B12) in plant-based products fortified using wheat bran extract fermented with B12-producing food-grade Propionibacterium freudenreichii was studied by applying a standard static in vitro model. At first, a culture of P. freudenreichii, fresh or heat-treated, was subjected to in vitro assays. Then, food ingredients or products were evaluated for their in vitro bioaccessibility: spray-dried wheat bran extract powder, pasta made with an extruder using fermented bran extract and breads made with spray-dried powder or with added cyanocobalamin. B12 bioaccessibility from the fresh P. freudenreichii culture was only ca. 53%, which, when heated, increased to 73%. The bioaccessibility of B12 from the food products varied from 75% (spray-dried powder) to 95% (breads). B12 from the fortified bread was as bioaccessible as from the bread made with added cyanocobalamin (99%). The in vitro results suggest that B12 synthesized by P. freudenreichii, when fortified in the studied cereal-based products, is largely bioaccessible and could be available for absorption. Plant-based products fortified using fermentation with P. freudenreichii could thus be considered excellent sources of bioaccessible B12.
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Affiliation(s)
- Bhawani Chamlagain
- Department of Food and Nutrition, University of Helsinki, P.O. Box 66, FI, 00014, University of Helsinki, Finland
| | - Liisa Peltonen
- Department of Food and Nutrition, University of Helsinki, P.O. Box 66, FI, 00014, University of Helsinki, Finland
| | - Minnamari Edelmann
- Department of Food and Nutrition, University of Helsinki, P.O. Box 66, FI, 00014, University of Helsinki, Finland
| | - Jose Martin Ramos-Diaz
- Department of Food and Nutrition, University of Helsinki, P.O. Box 66, FI, 00014, University of Helsinki, Finland
| | - Asmo Kemppinen
- Department of Food and Nutrition, University of Helsinki, P.O. Box 66, FI, 00014, University of Helsinki, Finland
| | - Kirsi Jouppila
- Department of Food and Nutrition, University of Helsinki, P.O. Box 66, FI, 00014, University of Helsinki, Finland
| | - Pekka Varmanen
- Department of Food and Nutrition, University of Helsinki, P.O. Box 66, FI, 00014, University of Helsinki, Finland
| | - Vieno Piironen
- Department of Food and Nutrition, University of Helsinki, P.O. Box 66, FI, 00014, University of Helsinki, Finland
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McCubbin T, Gonzalez-Garcia RA, Palfreyman RW, Stowers C, Nielsen LK, Marcellin E. A Pan-Genome Guided Metabolic Network Reconstruction of Five Propionibacterium Species Reveals Extensive Metabolic Diversity. Genes (Basel) 2020; 11:E1115. [PMID: 32977700 DOI: 10.3390/genes11101115] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/09/2020] [Accepted: 09/10/2020] [Indexed: 01/19/2023] Open
Abstract
Propionibacteria have been studied extensively since the early 1930s due to their relevance to industry and importance as human pathogens. Still, their unique metabolism is far from fully understood. This is partly due to their signature high GC content, which has previously hampered the acquisition of quality sequence data, the accurate annotation of the available genomes, and the functional characterization of genes. The recent completion of the genome sequences for several species has led researchers to reassess the taxonomical classification of the genus Propionibacterium, which has been divided into several new genres. Such data also enable a comparative genomic approach to annotation and provide a new opportunity to revisit our understanding of their metabolism. Using pan-genome analysis combined with the reconstruction of the first high-quality Propionibacterium genome-scale metabolic model and a pan-metabolic model of current and former members of the genus Propionibacterium, we demonstrate that despite sharing unique metabolic traits, these organisms have an unexpected diversity in central carbon metabolism and a hidden layer of metabolic complexity. This combined approach gave us new insights into the evolution of Propionibacterium metabolism and led us to propose a novel, putative ferredoxin-linked energy conservation strategy. The pan-genomic approach highlighted key differences in Propionibacterium metabolism that reflect adaptation to their environment. Results were mathematically captured in genome-scale metabolic reconstructions that can be used to further explore metabolism using metabolic modeling techniques. Overall, the data provide a platform to explore Propionibacterium metabolism and a tool for the rational design of strains.
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Abstract
Background: n-Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) catalyses the NAD
+-dependent oxidative phosphorylation of n-glyceraldehyde-3-phosphate to 1,3-diphospho-n-glycerate and its reverse reaction in glycolysis and gluconeogenesis. Methods: Four distinct crystal structures of human n-Glyceraldehyde-3-phosphate dehydrogenase (
HsGAPDH) have been determined from protein purified from the supernatant of HEK293F human epithelial kidney cells. Results: X-ray crystallography and mass-spectrometry indicate that the catalytic cysteine of the protein (
HsGAPDH Cys152) is partially oxidised to cysteine S-sulfonic acid. The average occupancy for the Cys152-S-sulfonic acid modification over the 20 crystallographically independent copies of
HsGAPDH across three of the crystal forms obtained is 0.31±0.17. Conclusions: The modification induces no significant structural changes on the tetrameric enzyme, and only makes aspecific contacts to surface residues in the active site, in keeping with the hypothesis that the oxidising conditions of the secreted mammalian cell expression system result in
HsGAPDH catalytic cysteine S-sulfonic acid modification and irreversible inactivation of the enzyme.
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Affiliation(s)
- Andrea Lia
- Leicester Institute of Chemical and Structural Biology and Department of Molecular and Cell Biology, University of Leicester, Henry Wellcome Building, Lancaster Road, LE1 7HB, UK.,Institute of Sciences of Food Production, C.N.R. Unit of Lecce, ia Monteroni, Lecce, 73100, Italy
| | - Adam Dowle
- Bioscience Technology Facility Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK
| | - Chris Taylor
- Bioscience Technology Facility Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK
| | - Angelo Santino
- Institute of Sciences of Food Production, C.N.R. Unit of Lecce, ia Monteroni, Lecce, 73100, Italy
| | - Pietro Roversi
- Leicester Institute of Chemical and Structural Biology and Department of Molecular and Cell Biology, University of Leicester, Henry Wellcome Building, Lancaster Road, LE1 7HB, UK
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Rodovalho VDR, da Luz BSR, Rabah H, do Carmo FLR, Folador EL, Nicolas A, Jardin J, Briard-Bion V, Blottière H, Lapaque N, Jan G, Le Loir Y, de Carvalho Azevedo VA, Guédon E. Extracellular Vesicles Produced by the Probiotic Propionibacterium freudenreichii CIRM-BIA 129 Mitigate Inflammation by Modulating the NF-κB Pathway. Front Microbiol 2020; 11:1544. [PMID: 32733422 PMCID: PMC7359729 DOI: 10.3389/fmicb.2020.01544] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 06/15/2020] [Indexed: 12/20/2022] Open
Abstract
Extracellular vesicles (EVs) are nanometric spherical structures involved in intercellular communication, whose production is considered to be a widespread phenomenon in living organisms. Bacterial EVs are associated with several processes that include survival, competition, pathogenesis, and immunomodulation. Among probiotic Gram-positive bacteria, some Propionibacterium freudenreichii strains exhibit anti-inflammatory activity, notably via surface proteins such as the surface-layer protein B (SlpB). We have hypothesized that, in addition to surface exposure and secretion of proteins, P. freudenreichii may produce EVs and thus export immunomodulatory proteins to interact with the host. In order to demonstrate their production in this species, EVs were purified from cell-free culture supernatants of the probiotic strain P. freudenreichii CIRM-BIA 129, and their physicochemical characterization, using transmission electron microscopy and nanoparticle tracking analysis (NTA), revealed shapes and sizes typical of EVs. Proteomic characterization showed that EVs contain a broad range of proteins, including immunomodulatory proteins such as SlpB. In silico protein-protein interaction predictions indicated that EV proteins could interact with host proteins, including the immunomodulatory transcription factor NF-κB. This potential interaction has a functional significance because EVs modulate inflammatory responses, as shown by IL-8 release and NF-κB activity, in HT-29 human intestinal epithelial cells. Indeed, EVs displayed an anti-inflammatory effect by modulating the NF-κB pathway; this was dependent on their concentration and on the proinflammatory inducer (LPS-specific). Moreover, while this anti-inflammatory effect partly depended on SlpB, it was not abolished by EV surface proteolysis, suggesting possible intracellular sites of action for EVs. This is the first report on identification of P. freudenreichii-derived EVs, alongside their physicochemical, biochemical and functional characterization. This study has enhanced our understanding of the mechanisms associated with the probiotic activity of P. freudenreichii and identified opportunities to employ bacterial-derived EVs for the development of bioactive products with therapeutic effects.
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Affiliation(s)
- Vinícius de Rezende Rodovalho
- INRAE, Institut Agro, STLO, Rennes, France.,Laboratory of Cellular and Molecular Genetics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Brenda Silva Rosa da Luz
- INRAE, Institut Agro, STLO, Rennes, France.,Laboratory of Cellular and Molecular Genetics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | | | - Fillipe Luiz Rosa do Carmo
- Laboratory of Cellular and Molecular Genetics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Edson Luiz Folador
- Biotechnology Center, Federal University of Paraíba, João Pessoa, Brazil
| | | | | | | | - Hervé Blottière
- INRAE, AgroParisTech, Paris-Saclay University, Micalis Institute, Jouy-en-Josas, France
| | - Nicolas Lapaque
- INRAE, AgroParisTech, Paris-Saclay University, Micalis Institute, Jouy-en-Josas, France
| | | | | | - Vasco Ariston de Carvalho Azevedo
- Laboratory of Cellular and Molecular Genetics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
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Lia A, Dowle A, Taylor C, Santino A, Roversi P. Partial catalytic Cys oxidation of human GAPDH. Wellcome Open Res 2020; 5:114. [DOI: 10.12688/wellcomeopenres.15893.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/21/2020] [Indexed: 11/20/2022] Open
Abstract
Background: n-Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) catalyses the reversible NAD+-dependent oxidative phosphorylation of n-glyceraldehyde-3-phosphate to 1,3-diphospho-n-glycerate in both glycolysis and gluconeogenesis.Methods: Four distinct crystal structures of human n-Glyceraldehyde-3-phosphate dehydrogenase (HsGAPDH) have been determined from protein purified from the supernatant of HEK293F human epithelial kidney cells.Results: X-ray crystallography and mass-spectrometry indicate that the catalytic cysteine of the protein (HsGAPDH Cys152) is partially oxidised to cysteine S-sulfonic acid. The average occupancy for the Cys152-S-sulfonic acid modification over the 20 crystallographically independent copies ofHsGAPDH across three of the crystal forms obtained is 0.31±0.17.Conclusions: The modification induces no significant structural changes on the tetrameric enzyme, and only makes aspecific contacts to surface residues in the active site, in keeping with the hypothesis that the oxidising conditions of the secreted mammalian cell expression system result inHsGAPDH catalytic cysteine S-sulfonic acid modification and irreversible inactivation of the enzyme.
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6
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Erdmann J, Thöming JG, Pohl S, Pich A, Lenz C, Häussler S. The Core Proteome of Biofilm-Grown Clinical Pseudomonas aeruginosa Isolates. Cells 2019; 8:E1129. [PMID: 31547513 PMCID: PMC6829490 DOI: 10.3390/cells8101129] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 09/18/2019] [Accepted: 09/19/2019] [Indexed: 12/13/2022] Open
Abstract
Comparative genomics has greatly facilitated the identification of shared as well as unique features among individual cells or tissues, and thus offers the potential to find disease markers. While proteomics is recognized for its potential to generate quantitative maps of protein expression, comparative proteomics in bacteria has been largely restricted to the comparison of single cell lines or mutant strains. In this study, we used a data independent acquisition (DIA) technique, which enables global protein quantification of large sample cohorts, to record the proteome profiles of overall 27 whole genome sequenced and transcriptionally profiled clinical isolates of the opportunistic pathogen Pseudomonas aeruginosa. Analysis of the proteome profiles across the 27 clinical isolates grown under planktonic and biofilm growth conditions led to the identification of a core biofilm-associated protein profile. Furthermore, we found that protein-to-mRNA ratios between different P. aeruginosa strains are well correlated, indicating conserved patterns of post-transcriptional regulation. Uncovering core regulatory pathways, which drive biofilm formation and associated antibiotic tolerance in bacterial pathogens, promise to give clues to interactions between bacterial species and their environment and could provide useful targets for new clinical interventions to combat biofilm-associated infections.
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Affiliation(s)
- Jelena Erdmann
- Institute for Molecular Bacteriology, TWINCORE GmbH, Centre for Experimental and Clinical Infection Research, a joint venture of the Hannover Medical School and the Helmholtz Centre for Infection Research, Hannover 30625, Germany.
- Research Core Unit Proteomics and Institute of Toxicology, Hannover Medical School, Hannover 30625, Germany.
| | - Janne G Thöming
- Institute for Molecular Bacteriology, TWINCORE GmbH, Centre for Experimental and Clinical Infection Research, a joint venture of the Hannover Medical School and the Helmholtz Centre for Infection Research, Hannover 30625, Germany.
| | - Sarah Pohl
- Institute for Molecular Bacteriology, TWINCORE GmbH, Centre for Experimental and Clinical Infection Research, a joint venture of the Hannover Medical School and the Helmholtz Centre for Infection Research, Hannover 30625, Germany.
- Department of Molecular Bacteriology, Helmholtz Center for Infection Research, Braunschweig 38124, Germany.
| | - Andreas Pich
- Research Core Unit Proteomics and Institute of Toxicology, Hannover Medical School, Hannover 30625, Germany.
| | - Christof Lenz
- Institute of Clinical Chemistry, Bioanalytics, University Medical Center Göttingen, Göttingen 37075, Germany.
- Max Planck Institute for Biophysical Chemistry, Bioanalytical Mass Spectrometry, Göttingen 37077, Germany.
| | - Susanne Häussler
- Institute for Molecular Bacteriology, TWINCORE GmbH, Centre for Experimental and Clinical Infection Research, a joint venture of the Hannover Medical School and the Helmholtz Centre for Infection Research, Hannover 30625, Germany.
- Department of Molecular Bacteriology, Helmholtz Center for Infection Research, Braunschweig 38124, Germany.
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do Carmo FLR, Silva WM, Tavares GC, Ibraim IC, Cordeiro BF, Oliveira ER, Rabah H, Cauty C, da Silva SH, Canário Viana MV, Caetano ACB, Dos Santos RG, de Oliveira Carvalho RD, Jardin J, Pereira FL, Folador EL, Le Loir Y, Figueiredo HCP, Jan G, Azevedo V. Mutation of the Surface Layer Protein SlpB Has Pleiotropic Effects in the Probiotic Propionibacterium freudenreichii CIRM-BIA 129. Front Microbiol 2018; 9:1807. [PMID: 30174657 PMCID: PMC6107788 DOI: 10.3389/fmicb.2018.01807] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 07/18/2018] [Indexed: 01/19/2023] Open
Abstract
Propionibacterium freudenreichii is a beneficial Gram-positive bacterium, traditionally used as a cheese-ripening starter, and currently considered as an emerging probiotic. As an example, the P. freudenreichii CIRM-BIA 129 strain recently revealed promising immunomodulatory properties. Its consumption accordingly exerts healing effects in different animal models of colitis, suggesting a potent role in the context of inflammatory bowel diseases. This anti-inflammatory effect depends on surface layer proteins (SLPs). SLPs may be involved in key functions in probiotics, such as persistence within the gut, adhesion to host cells and mucus, or immunomodulation. Several SLPs coexist in P. freudenreichii CIRM-BIA 129 and mediate immunomodulation and adhesion. A mutant P. freudenreichii CIRM-BIA 129ΔslpB (CB129ΔslpB) strain was shown to exhibit decreased adhesion to intestinal epithelial cells. In the present study, we thoroughly analyzed the impact of this mutation on cellular properties. Firstly, we investigated alterations of surface properties in CB129ΔslpB. Surface extractable proteins, surface charges (ζ-potential) and surface hydrophobicity were affected by the mutation. Whole-cell proteomics, using high definition mass spectrometry, identified 1,288 quantifiable proteins in the wild-type strain, i.e., 53% of the theoretical proteome predicted according to P. freudenreichii CIRM-BIA 129 genome sequence. In the mutant strain, we detected 1,252 proteins, including 1,227 proteins in common with the wild-type strain. Comparative quantitative analysis revealed 97 proteins with significant differences between wild-type and mutant strains. These proteins are involved in various cellular process like signaling, metabolism, and DNA repair and replication. Finally, in silico analysis predicted that slpB gene is not part of an operon, thus not affecting the downstream genes after gene knockout. This study, in accordance with the various roles attributed in the literature to SLPs, revealed a pleiotropic effect of a single slpB mutation, in the probiotic P. freudenreichii. This suggests that SlpB may be at a central node of cellular processes and confirms that both nature and amount of SLPs, which are highly variable within the P. freudenreichii species, determine the probiotic abilities of strains.
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Affiliation(s)
- Fillipe L R do Carmo
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.,Institut National de la Recherche Agronomique, UMR1253 Science & Technologie du Lait & de l'Oeuf, Rennes, France.,Agrocampus Ouest, UMR1253 Science & Technologie du Lait & de l'Oeuf, Rennes, France
| | - Wanderson M Silva
- Instituto de Biotecnología, CICVyA - Instituto Nacional de Tecnología Agropecuaria, Hurlingham, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Guilherme C Tavares
- AQUACEN, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Izabela C Ibraim
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Barbara F Cordeiro
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Emiliano R Oliveira
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Houem Rabah
- Institut National de la Recherche Agronomique, UMR1253 Science & Technologie du Lait & de l'Oeuf, Rennes, France.,Agrocampus Ouest, UMR1253 Science & Technologie du Lait & de l'Oeuf, Rennes, France
| | - Chantal Cauty
- Institut National de la Recherche Agronomique, UMR1253 Science & Technologie du Lait & de l'Oeuf, Rennes, France
| | - Sara H da Silva
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Marcus V Canário Viana
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Ana C B Caetano
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Roselane G Dos Santos
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | - Julien Jardin
- Institut National de la Recherche Agronomique, UMR1253 Science & Technologie du Lait & de l'Oeuf, Rennes, France
| | - Felipe L Pereira
- AQUACEN, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Edson L Folador
- Centro de Biotecnologia, Universidade Federal da Paraíba, João Pessoa, Brazil
| | - Yves Le Loir
- Institut National de la Recherche Agronomique, UMR1253 Science & Technologie du Lait & de l'Oeuf, Rennes, France.,Agrocampus Ouest, UMR1253 Science & Technologie du Lait & de l'Oeuf, Rennes, France
| | - Henrique C P Figueiredo
- AQUACEN, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Gwénaël Jan
- Institut National de la Recherche Agronomique, UMR1253 Science & Technologie du Lait & de l'Oeuf, Rennes, France.,Agrocampus Ouest, UMR1253 Science & Technologie du Lait & de l'Oeuf, Rennes, France
| | - Vasco Azevedo
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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Frohnmeyer E, Deptula P, Nyman TA, Laine PKS, Vihinen H, Paulin L, Auvinen P, Jokitalo E, Piironen V, Varmanen P, Savijoki K. Secretome profiling of Propionibacterium freudenreichii reveals highly variable responses even among the closely related strains. Microb Biotechnol 2018; 11:510-526. [PMID: 29488359 PMCID: PMC5902329 DOI: 10.1111/1751-7915.13254] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 01/19/2018] [Indexed: 12/20/2022] Open
Abstract
This study compared the secretomes (proteins exported out of the cell) of Propionibacterium freudenreichii of different origin to identify plausible adaptation factors. Phylosecretomics indicated strain‐specific variation in secretion of adhesins/invasins (SlpA, InlA), cell‐wall hydrolysing (NlpC60 peptidase, transglycosylase), protective (RpfB) and moonlighting (DnaK, GroEL, GaPDH, IDH, ENO, ClpB) enzymes and/or proteins. Detailed secretome comparison suggested that one of the cereal strains (JS14) released a tip fimbrillin (FimB) in to the extracellular milieu, which was in line with the electron microscopy and genomic analyses, indicating the lack of surface‐associated fimbrial‐like structures, predicting a mutated type‐2 fimbrial gene cluster (fimB‐fimA‐srtC2) and production of anchorless FimB. Instead, the cereal strain produced high amounts of SlpB that tentatively mediated adherent growth on hydrophilic surface and adherence to hydrophobic material. One of the dairy strains (JS22), producing non‐covalently bound surface‐proteins (LspA, ClpB, AraI) and releasing SlpA and InlA into the culture medium, was found to form clumps under physiological conditions. The JS22 strain lacked SlpB and displayed a non‐clumping and biofilm‐forming phenotype only under conditions of increased ionic strength (300 mM NaCl). However, this strain cultured under the same conditions was not adherent to hydrophobic support, which supports the contributory role of SlpB in mediating hydrophobic interactions. Thus, this study reports significant secretome variation in P. freudenreichii and suggests that strain‐specific differences in protein export, modification and protein–protein interactions have been the driving forces behind the adaptation of this bacterial species.
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Affiliation(s)
- Esther Frohnmeyer
- Department of Food and Environmental Sciences, University of Helsinki, Helsinki 00014, Finland
| | - Paulina Deptula
- Department of Food and Environmental Sciences, University of Helsinki, Helsinki 00014, Finland
| | - Tuula A Nyman
- Department of Immunology, Institute of Clinical Medicine, University of Oslo, 0424 Oslo, Norway
| | - Pia K S Laine
- DNA Sequencing and Genomics Lab, Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
| | - Helena Vihinen
- Electron Microscopy Unit, Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
| | - Lars Paulin
- DNA Sequencing and Genomics Lab, Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
| | - Petri Auvinen
- DNA Sequencing and Genomics Lab, Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
| | - Eija Jokitalo
- Electron Microscopy Unit, Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
| | - Vieno Piironen
- Department of Food and Environmental Sciences, University of Helsinki, Helsinki 00014, Finland
| | - Pekka Varmanen
- Department of Food and Environmental Sciences, University of Helsinki, Helsinki 00014, Finland
| | - Kirsi Savijoki
- Department of Food and Environmental Sciences, University of Helsinki, Helsinki 00014, Finland
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