scholarly journals The key role of the mycolic acid content in the functionality of the cell wall permeability barrier in Corynebacterineae

Microbiology ◽  
2007 ◽  
Vol 153 (5) ◽  
pp. 1424-1434 ◽  
Author(s):  
Henrike Gebhardt ◽  
Xavier Meniche ◽  
Marielle Tropis ◽  
Reinhard Krämer ◽  
Mamadou Daffé ◽  
...  
Keyword(s):  
Cell Wall ◽  
Acid Content ◽  
Mycolic Acid ◽  
Permeability Barrier ◽  
Wall Permeability ◽  
Cell Wall Permeability

scholarly journals Carbon Source-Induced Modifications in the Mycolic Acid Content and Cell Wall Permeability of Rhodococcus erythropolis E1

2003 ◽  
Vol 69 (12) ◽  
pp. 7019-7027 ◽  
Author(s):  
Ivana Sokolovská ◽  
Raoul Rozenberg ◽  
Christophe Riez ◽  
Paul G. Rouxhet ◽  
Spiros N. Agathos ◽  
...  
Keyword(s):  
Cell Wall ◽  
Carbon Source ◽  
Acid Content ◽  
Rhodococcus Erythropolis ◽  
Mycolic Acid ◽  
Mycolic Acids ◽  
Carbon Chains ◽  
Linear Alkanes ◽  
Wall Permeability ◽  
Cell Wall Permeability

ABSTRACT The influence of the carbon source on cell wall properties was analyzed in an efficient alkane-degrading strain of Rhodococcus erythropolis (strain E1), with particular focus on the mycolic acid content. A clear correlation was observed between the carbon source and the mycolic acid profiles as estimated by high-performance liquid chromatography and mass spectrometry. Two types of mycolic acid patterns were observed after growth either on saturated linear alkanes or on short-chain alkanoates. One type of pattern was characterized by the lack of odd-numbered carbon chains and resulted from growth on linear alkanes with even numbers of carbon atoms. The second type of pattern was characterized by mycolic acids with both even- and odd-numbered carbon chains and resulted from growth on compounds with odd-numbered carbon chains, on branched alkanes, or on mixtures of different compounds. Cellular short-chain fatty acids were twice as abundant during growth on a branched alkane (pristane) as during growth on acetate, while equal amounts of mycolic acids were found under both conditions. More hydrocarbon-like compounds and less polysaccharide were exposed at the cell wall surface during growth on alkanes. Whatever the substrate, the cells had the same affinity for aqueous-nonaqueous solvent interfaces. By contrast, bacteria displayed completely opposite susceptibilities to hydrophilic and hydrophobic antibiotics and were found to be strongly stained by hydrophobic dyes after growth on pristane but not after growth on acetate. Taken together, these data show that the cell wall composition of R. erythropolis E1 is influenced by the nutritional regimen and that the most marked effect is a radical change in cell wall permeability.

scholarly journals Both Phthiocerol Dimycocerosates and Phenolic Glycolipids Are Required for Virulence of Mycobacterium marinum

2012 ◽  
Vol 80 (4) ◽  
pp. 1381-1389 ◽  
Author(s):  
Jia Yu ◽  
Vanessa Tran ◽  
Ming Li ◽  
Xinghua Huang ◽  
Chen Niu ◽  
...  
Keyword(s):  
Cell Wall ◽  
Mycobacterium Marinum ◽  
Content Type ◽  
Transposon Insertion ◽  
Wall Permeability ◽  
Cell Wall Permeability ◽  
Phthiocerol Dimycocerosates ◽  
Zebrafish Infection ◽  
Phenolic Glycolipids

ABSTRACTPhthiocerol dimycocerosates (PDIMs) and structurally related phenolic glycolipids (PGLs) are complex cell wall lipids unique to pathogenic mycobacteria. While these lipids have been extensively studied in recent years, there are conflicting reports on some aspects of their biosynthesis and on the role of PDIMs and especially PGLs in virulence ofMycobacterium tuberculosis. This has been complicated by the natural deficiency of PGLs in many clinical strains ofM. tuberculosisand the frequent loss of PDIMs in laboratoryM. tuberculosisstrains. In this study, we isolated seven mutants ofMycobacterium marinumdeficient in PDIMs and/or PGLs in which multiple genes of the PDIM/PGL biosynthetic locus were disrupted by transposon insertion. Zebrafish infection experiments showed thatM. marinumstrains lacking one or both of these lipids were avirulent, suggesting that both PDIMs and PGLs are required for virulence. We also found that these strains were hypersensitive to antibiotics and exhibited increased cell wall permeability. Our studies provide new insights into the biosynthesis of PDIMs/PGLs and may help us to understand the role of PDIMs and PGLs inM. tuberculosisvirulence.

scholarly journals Structure of the cell envelope of corynebacteria: importance of the non-covalently bound lipids in the formation of the cell wall permeability barrier and fracture plane

Microbiology ◽  
2001 ◽  
Vol 147 (5) ◽  
pp. 1365-1382 ◽  
Author(s):  
Virginie Puech ◽  
Mohamed Chami ◽  
Anne Lemassu ◽  
Marie-Antoinette Lanéelle ◽  
Bettina Schiffler ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Envelope ◽  
Fracture Plane ◽  
Permeability Barrier ◽  
Bound Lipids ◽  
Wall Permeability ◽  
Cell Wall Permeability ◽  
Covalently Bound

Cell Wall Permeability of Pinto Bean Cotyledon Cells Regulates In Vitro Fecal Fermentation and Gut Microbiota

2021 ◽  
Author(s):  
Yanrong Huang ◽  
Sushil Dhital ◽  
Feitong Liu ◽  
Xiong Fu ◽  
Qiang Huang ◽  
...  
Keyword(s):  
Cell Wall ◽  
Structural Changes ◽  
Microbiota Composition ◽  
Colonic Fermentation ◽  
Pinto Bean ◽  
Wall Permeability ◽  
Cell Wall Permeability ◽  
Cotyledon Cells ◽  
Whole Foods

Processing induced structural changes of whole foods on regulation of colonic fermentation rate and microbiota composition are least understood and often overlooked. In the present study, intact cotyledon cells from...

scholarly journals A Tetrameric Porin Limits the Cell Wall Permeability ofMycobacterium smegmatis

2002 ◽  
Vol 277 (40) ◽  
pp. 37567-37572 ◽  
Author(s):  
Harald Engelhardt ◽  
Christian Heinz ◽  
Michael Niederweis
Keyword(s):  
Cell Wall ◽  
Wall Permeability ◽  
Cell Wall Permeability

scholarly journals The M. tuberculosis Rv1523 Methyltransferase Promotes Drug Resistance Through Methylation-Mediated Cell Wall Remodeling and Modulates Macrophages Immune Responses

2021 ◽  
Vol 11 ◽  
Author(s):  
Sabeeha Ali ◽  
Aquib Ehtram ◽  
Naresh Arora ◽  
P. Manjunath ◽  
Deodutta Roy ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Cell Wall ◽  
Immune Responses ◽  
Molecular Mechanisms ◽  
Mycolic Acid ◽  
Antibiotics Resistance ◽  
Effective Prevention ◽  
Resistance To Antibiotics ◽  
Cell Wall Remodeling

The acquisition of antibiotics resistance is a major clinical challenge limiting the effective prevention and treatment of the deadliest human infectious disease tuberculosis. The molecular mechanisms by which initially Mycobacterium tuberculosis (M.tb) develop drug resistance remain poorly understood. In this study, we report the novel role of M.tb Rv1523 MTase in the methylation of mycobacterial cell envelope lipids and possible mechanism of its contribution in the virulence and drug resistance. Initial interactome analyses predicted association of Rv1523 with proteins related to fatty acid biosynthetic pathways. This promoted us to investigate methylation activity of Rv1523 using cell wall fatty acids or lipids as a substrate. Rv1523 catalyzed the transfer of methyl group from SAM to the cell wall components of mycobacterium. To investigate further the in vivo methylating role of Rv1523, we generated a recombinant Mycobacterium smegmatis strain that expressed the Rv1523 gene. The M. smegmatis strain expressing Rv1523 exhibited altered cell wall lipid composition, leading to an increased survival under surface stress, acidic condition and resistance to antibiotics. Macrophages infected with recombinant M. smegmatis induced necrotic cell death and modulated the host immune responses. In summary, these findings reveal a hitherto unknown role of Rv1523 encoded MTase in cell wall remodeling and modulation of immune responses. Functional gain of mycolic acid Rv1523 methyltransferase induced virulence and resistance to antibiotics in M. smegmatis. Thus, mycolic acid methyltransferase may serve as an excellent target for the discovery and development of novel anti-TB agents.

scholarly journals The Activity of Cell-Wall Modifying β-1,3-Glucanases in Soybean Grown in Presence of Heavy Metals

2016 ◽  
Vol 15 (2) ◽  
pp. 114-121
Author(s):  
Monika Bardáčová ◽  
Marína Maglovski ◽  
Zuzana Gregorová ◽  
Yevheniia Konotop ◽  
Miroslav Horník ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Cell Wall ◽  
Cell Walls ◽  
Regulation Mechanism ◽  
Soybean Variety ◽  
Toxic Heavy Metals ◽  
Metal Sequestration ◽  
Enzyme Isoforms ◽  
Wall Permeability ◽  
Cell Wall Permeability

AbstractCell walls represent the first barrier that can prevent the entrance of toxic heavy metals into plants. The composition and the flexibility of the cell wall are regulated by different enzymes. The ß-1,3-glucanases control the degradation of the polysaccharide callose as a flexible regulation mechanism of cell wall permeability and/or its ability to bind metals under stress conditions. The profile and activity of ß-1,3-glucanases in the presence of heavy metals, however, has rarely been studied. Here we studied these enzymes in four soybean varieties (Glycine max) grown in the presence of cadmium ions. These analyses revealed three acidic and one basic enzyme isoforms in each soybean variety, but only two of the acidic isoforms in the variety Moravians were substantially responsive to the presence of Cd2+. Since the responses of certain glucanases were detected mainly in the varieties sensitive to metal and accumulating high amounts of metals, we assume their role in the defense rather than strategic metal sequestration.

scholarly journals Impact of Methoxymycolic Acid Production by Mycobacterium bovis BCG Vaccines

2004 ◽  
Vol 72 (5) ◽  
pp. 2803-2809 ◽  
Author(s):  
Adam Belley ◽  
David Alexander ◽  
Tania Di Pietrantonio ◽  
Manon Girard ◽  
Joses Jones ◽  
...  
Keyword(s):  
Cell Wall ◽  
Mycobacterium Bovis ◽  
Acid Production ◽  
Acid Synthesis ◽  
Permeability Barrier ◽  
Mycolic Acids ◽  
Cell Wall Permeability ◽  
The Impact

ABSTRACT BCG vaccines are a family of closely related daughter strains of an attenuated isolate of Mycobacterium bovis derived by in vitro passage from 1908 to 1921. During subsequent laboratory propagation of the vaccine strain until its lyophilization in 1961, BCG Pasteur underwent at least seven further genomic mutations. The impact of these mutations on the properties of the vaccine is currently unknown. One mutation, a glycine-to-aspartic acid substitution in the mmaA3 gene, occurred between 1927 and 1931 and impairs methoxymycolic acid synthesis in BCG strains obtained from the Pasteur Institute after this period. Mycolic acids of the cell wall are classified into three functional groups (alpha-, methoxy-, and ketomycolic acids), and together these lipids form a highly specialized permeability barrier around the bacterium. To explore the impact of methoxymycolic acid production by BCG strains, we complemented the functional gene of mmaA3 into BCG Denmark and tested a number of in vitro and in vivo phenotypes. Surprisingly, restoration of methoxymycolic acids alone had no effect on cell wall permeability, resistance to antibiotics, or growth in cultured macrophages and C57BL/6 mice. Our results demonstrate that the loss of methoxymycolic acid production did not apparently affect the virulence of BCG strains.

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