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Merz M, Schiffer CJ, Klingl A, Ehrmann MA. Characterization of the major autolysin (AtlC) of Staphylococcus carnosus. BMC Microbiol 2024; 24:77. [PMID: 38459514 PMCID: PMC10921637 DOI: 10.1186/s12866-024-03231-6] [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: 11/10/2023] [Accepted: 02/21/2024] [Indexed: 03/10/2024] Open
Abstract
BACKGROUND Autolysis by cellular peptidoglycan hydrolases (PGH) is a well-known phenomenon in bacteria. During food fermentation, autolysis of starter cultures can exert an accelerating effect, as described in many studies on cheese ripening. In contrast, very little is known about autolysis of starter cultures used in other fermentations. Staphylococcus (S.) carnosus is often used in raw sausage fermentations, contributing to nitrate reduction and flavor formation. In this study, we analyzed the influence of PGHs of the strains S. carnosus TMW 2.146 and S. carnosus TMW 2.2525 on their autolytic behavior. The staphylococcal major autolysin (Atl), a bifunctional enzyme with an N-acetylmuramoyl-L-alanine amidase and a glucosaminidase as an active site, is assumed to be the enzyme by which autolysis is mainly mediated. RESULTS AtlC mutant strains showed impaired growth and almost no autolysis compared to their respective wild-type strains. Light microscopy and scanning electron microscopy showed that the mutants could no longer appropriately separate from each other during cell division, resulting in the formation of cell clusters. The surface of the mutants appeared rough with an irregular morphology compared to the smooth cell surfaces of the wild-types. Moreover, zymograms showed that eight lytic bands of S. carnosus, with a molecular mass between 140 and 35 kDa, are processed intermediates of AtlC. It was noticed that additional bands were found that had not been described in detail before and that the banding pattern changes over time. Some bands disappear entirely, while others become stronger or are newly formed. This suggests that AtlC is degraded into smaller fragments over time. A second knockout was generated for the gene encoding a N-acetylmuramoyl-L-alanine amidase domain-containing protein. Still, no phenotypic differences could be detected in this mutant compared to the wild-type, implying that the autolytic activity of S. carnosus is mediated by AtlC. CONCLUSIONS In this study, two knockout mutants of S. carnosus were generated. The atlC mutant showed a significantly altered phenotype compared to the wild-type, revealing AtlC as a key factor in staphylococcal autolysis. Furthermore, we show that Atl is degraded into smaller fragments, which are still cell wall lytic active.
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Affiliation(s)
- Maximilian Merz
- Chair of Microbiology, Technical University of Munich, Gregor-Mendel-Straße 4, 85354, Freising, Germany
| | - Carolin J Schiffer
- Chair of Microbiology, Technical University of Munich, Gregor-Mendel-Straße 4, 85354, Freising, Germany
| | - Andreas Klingl
- Plant Development, Department Biology I - Botany, Ludwig-Maximilians-Universität München, Großhaderner Str. 2-4, 82152, Planegg-Martinsried, Germany
| | - Matthias A Ehrmann
- Chair of Microbiology, Technical University of Munich, Gregor-Mendel-Straße 4, 85354, Freising, Germany.
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Yang S, Bai M, Kwok LY, Zhong Z, Sun Z. The intricate symbiotic relationship between lactic acid bacterial starters in the milk fermentation ecosystem. Crit Rev Food Sci Nutr 2023:1-18. [PMID: 37983125 DOI: 10.1080/10408398.2023.2280706] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Fermentation is one of the most effective methods of food preservation. Since ancient times, food has been fermented using lactic acid bacteria (LAB). Fermented milk is a very intricate fermentation ecosystem, and the microbial metabolism of fermented milk largely determines its metabolic properties. The two most frequently used dairy starter strains are Streptococcus thermophilus (S. thermophilus) and Lactobacillus delbrueckii subsp. bulgaricus (L. bulgaricus). To enhance both the culture growth rate and the flavor and quality of the fermented milk, it has long been customary to combine S. thermophilus and L. bulgaricus in milk fermentation due to their mutually beneficial and symbiotic relationship. On the one hand, the symbiotic relationship is reflected by the nutrient co-dependence of the two microbes at the metabolic level. On the other hand, more complex interaction mechanisms, such as quorum sensing between cells, are involved. This review summarizes the application of LAB in fermented dairy products and discusses the symbiotic mechanisms and interactions of milk LAB starter strains from the perspective of nutrient supply and intra- and interspecific quorum sensing. This review provides updated information and knowledge on microbial interactions in a fermented milk ecosystem.
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Affiliation(s)
- Shujuan Yang
- Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Inner Mongolia Agricultural University, Hohhot, PR China
- Key Laboratory of Dairy Products Processing, Ministry of Agriculture and Rural Affairs, Inner Mongolia Agricultural University, Hohhot, PR China
- Inner Mongolia Key Laboratory of Dairy Biotechnology and Engineering, Inner Mongolia Agricultural University, Hohhot, PR China
| | - Mei Bai
- Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Inner Mongolia Agricultural University, Hohhot, PR China
- Key Laboratory of Dairy Products Processing, Ministry of Agriculture and Rural Affairs, Inner Mongolia Agricultural University, Hohhot, PR China
- Inner Mongolia Key Laboratory of Dairy Biotechnology and Engineering, Inner Mongolia Agricultural University, Hohhot, PR China
| | - Lai-Yu Kwok
- Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Inner Mongolia Agricultural University, Hohhot, PR China
- Key Laboratory of Dairy Products Processing, Ministry of Agriculture and Rural Affairs, Inner Mongolia Agricultural University, Hohhot, PR China
- Inner Mongolia Key Laboratory of Dairy Biotechnology and Engineering, Inner Mongolia Agricultural University, Hohhot, PR China
| | - Zhi Zhong
- Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Inner Mongolia Agricultural University, Hohhot, PR China
- Key Laboratory of Dairy Products Processing, Ministry of Agriculture and Rural Affairs, Inner Mongolia Agricultural University, Hohhot, PR China
- Inner Mongolia Key Laboratory of Dairy Biotechnology and Engineering, Inner Mongolia Agricultural University, Hohhot, PR China
| | - Zhihong Sun
- Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Inner Mongolia Agricultural University, Hohhot, PR China
- Key Laboratory of Dairy Products Processing, Ministry of Agriculture and Rural Affairs, Inner Mongolia Agricultural University, Hohhot, PR China
- Inner Mongolia Key Laboratory of Dairy Biotechnology and Engineering, Inner Mongolia Agricultural University, Hohhot, PR China
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Imbalance between peptidoglycan synthases and hydrolases regulated lysis of Lactobacillus bulgaricus in batch culture. Arch Microbiol 2021; 203:4571-4578. [PMID: 34156502 DOI: 10.1007/s00203-021-02433-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 06/05/2021] [Accepted: 06/09/2021] [Indexed: 12/23/2022]
Abstract
Lactobacillus bulgaricus is an important starter culture in the dairy industry, cell lysis is negative to the high density of this strain. This work describes the response of peptidoglycan synthases and hydrolases in Lactobacillus bulgaricus sp1.1 when pH decreasing in batch culture. First, the cell lysis was investigated by measuring the cytosolic lactate dehydrogenase released to the fermentation broth, a continuous increase in extracellular lactate dehydrogenase was observed after the lag phase in batch culture. Then, the peptidoglycan hydrolases profile analyzed using the zymogram method showed that eight proteins have the ability of peptidoglycan hydrolysis, three of the eight proteins were considered to contribute lysis of L. bulgaricus sp1.1 according to the changes and extents of peptidoglycan hydrolysis. In silico analysis showed that three putative peptidoglycan hydrolases, including N-acetylmuramyl-L-Ala amidase (protein ID: ALT46642.1), amidase (protein ID: ALT46641.1), and N-acetylmuramidase (protein ID: WP_013439201.1) were compatible with these proteins. Finally, the transcription of the three putative peptidoglycan hydrolases was upregulated in batch culture, in contrast, the expression of four peptidoglycan synthases was downregulated. These observations suggested the imbalance between peptidoglycan synthases and hydrolases involved in the lysis of Lactobacillus bulgaricus sp1.1.
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Gene knockout revealed the role of gene feoA in cell growth and division of Lactobacillus delbrueckii subsp. bulgaricus. Arch Microbiol 2021; 203:3541-3549. [PMID: 33942158 DOI: 10.1007/s00203-021-02345-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 04/17/2021] [Accepted: 04/21/2021] [Indexed: 10/21/2022]
Abstract
Gene feoA plays an important role in cell growth because of its function of transport Fe2+ which is a necessary element for cells. In this study, the recombinant plasmid pUC19-feoA-Tet was successfully constructed using the inserted gene inactivation method. Using the homologous recombination technique, the tet gene was used as a resistance screening marker to knock out the feoA gene of Lactobacillus delbrueckii subsp. bulgaricus 34.5 (strain 34.5). Comparative analysis of growth curves revealed the growth changes in the absence of feoA gene in strain 34.5. The results showed that the growth of the bacteria was prolonged by 2 h and could be restored in the stationary phase. To further study whether feoA is related to the cell division of strain 34.5, the qPCR experiment was carried out. The results showed that, compared with the wild-type strain, the expression of genes related to cell division in the mutant strain was up-regulated in the pre-log phase, down-regulated in the late-log phase, and returned to the original level in the stationary phase. These findings provide ideas for Lactobacillus delbrueckii subsp. bulgaricus to control division and cell cycle.
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Rabah H, do Carmo FLR, Carvalho RDDO, Cordeiro BF, da Silva SH, Oliveira ER, Lemos L, Cara DC, Faria AMC, Garric G, Harel-Oger M, Le Loir Y, Azevedo V, Bouguen G, Jan G. Beneficial Propionibacteria within a Probiotic Emmental Cheese: Impact on Dextran Sodium Sulphate-Induced Colitis in Mice. Microorganisms 2020; 8:E380. [PMID: 32156075 PMCID: PMC7142753 DOI: 10.3390/microorganisms8030380] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 03/03/2020] [Accepted: 03/05/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUNDS AND AIMS Inflammatory Bowel Diseases (IBD), including Ulcerative Colitis (UC), coincide with alterations in the gut microbiota. Consumption of immunomodulatory strains of probiotic bacteria may induce or prolong remission in UC patients. Fermented foods, including cheeses, constitute major vectors for bacteria consumption. New evidences revealed anti-inflammatory effects in selected strains of Propionibacterium freudenreichii. We thus hypothesized that consumption of a functional cheese, fermented by such a strain, may exert a positive effect on IBD. METHODS We investigated the impact of cheese fermented by P. freudenreichii on gut inflammation. We developed an experimental single-strain cheese solely fermented by a selected immunomodulatory strain of P. freudenreichii, CIRM-BIA 129. We moreover produced, in industrial conditions, an Emmental cheese using the same strain, in combination with Lactobacillus delbrueckii CNRZ327 and Streptococcus thermophilus LMD-9, as starters. Consumption of both cheeses was investigated with respect to prevention of Dextran Sodium Sulphate (DSS)-induced colitis in mice. RESULTS Consumption of the single-strain experimental cheese, or of the industrial Emmental, both fermented by P. freudenreichii CIRM-BIA 129, reduced severity of subsequent DSS-induced colitis, weight loss, disease activity index and histological score. Both treatments, in a preventive way, reduced small bowel Immunoglobulin A (IgA) secretion, restored occludin gene expression and prevented induction of Tumor Necrosis Factor α (TNFα), Interferon γ (IFNγ) and Interleukin-17 (IL-17). CONCLUSIONS A combination of immunomodulatory strains of starter bacteria can be used to manufacture an anti-inflammatory cheese, as revealed in an animal model of colitis. This opens new perspectives for personalised nutrition in the context of IBD.
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Affiliation(s)
- Houem Rabah
- STLO, INRA, Agrocampus Ouest, 35 000 Rennes, France; (H.R.); (G.G.); (M.H.-O.); (Y.L.L.)
- Pôle Agronomique Ouest, Régions Bretagne et Pays de la Loire, F-35 042 Rennes, France
| | - Fillipe Luiz Rosa do Carmo
- Departamento de Genética, Ecologia e evolução, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais CP 486 CEP 31270-901, Brazil; (F.L.R.d.C.); (B.F.C.); (S.H.d.S.); (E.R.O.); (L.L.); (D.C.C.); (A.M.C.F.); (V.A.)
| | | | - Barbara Fernandes Cordeiro
- Departamento de Genética, Ecologia e evolução, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais CP 486 CEP 31270-901, Brazil; (F.L.R.d.C.); (B.F.C.); (S.H.d.S.); (E.R.O.); (L.L.); (D.C.C.); (A.M.C.F.); (V.A.)
| | - Sara Heloisa da Silva
- Departamento de Genética, Ecologia e evolução, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais CP 486 CEP 31270-901, Brazil; (F.L.R.d.C.); (B.F.C.); (S.H.d.S.); (E.R.O.); (L.L.); (D.C.C.); (A.M.C.F.); (V.A.)
| | - Emiliano Rosa Oliveira
- Departamento de Genética, Ecologia e evolução, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais CP 486 CEP 31270-901, Brazil; (F.L.R.d.C.); (B.F.C.); (S.H.d.S.); (E.R.O.); (L.L.); (D.C.C.); (A.M.C.F.); (V.A.)
| | - Luisa Lemos
- Departamento de Genética, Ecologia e evolução, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais CP 486 CEP 31270-901, Brazil; (F.L.R.d.C.); (B.F.C.); (S.H.d.S.); (E.R.O.); (L.L.); (D.C.C.); (A.M.C.F.); (V.A.)
| | - Denise Carmona Cara
- Departamento de Genética, Ecologia e evolução, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais CP 486 CEP 31270-901, Brazil; (F.L.R.d.C.); (B.F.C.); (S.H.d.S.); (E.R.O.); (L.L.); (D.C.C.); (A.M.C.F.); (V.A.)
| | - Ana Maria Caetano Faria
- Departamento de Genética, Ecologia e evolução, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais CP 486 CEP 31270-901, Brazil; (F.L.R.d.C.); (B.F.C.); (S.H.d.S.); (E.R.O.); (L.L.); (D.C.C.); (A.M.C.F.); (V.A.)
| | - Gilles Garric
- STLO, INRA, Agrocampus Ouest, 35 000 Rennes, France; (H.R.); (G.G.); (M.H.-O.); (Y.L.L.)
| | - Marielle Harel-Oger
- STLO, INRA, Agrocampus Ouest, 35 000 Rennes, France; (H.R.); (G.G.); (M.H.-O.); (Y.L.L.)
| | - Yves Le Loir
- STLO, INRA, Agrocampus Ouest, 35 000 Rennes, France; (H.R.); (G.G.); (M.H.-O.); (Y.L.L.)
| | - Vasco Azevedo
- Departamento de Genética, Ecologia e evolução, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais CP 486 CEP 31270-901, Brazil; (F.L.R.d.C.); (B.F.C.); (S.H.d.S.); (E.R.O.); (L.L.); (D.C.C.); (A.M.C.F.); (V.A.)
| | - Guillaume Bouguen
- CHU Rennes, Univ Rennes, INSERM, CIC1414, Institut NUMECAN (Nutrition Metabolism and Cancer), F-35000 Rennes, France;
| | - Gwénaël Jan
- STLO, INRA, Agrocampus Ouest, 35 000 Rennes, France; (H.R.); (G.G.); (M.H.-O.); (Y.L.L.)
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