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 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 The Assessment of Viability of M. Tuberculosis after Exposure to CPC Using Different Methods

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Gomathi Sekar ◽  
R. Lakshmi ◽  
N. Selvakumar
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Metabolic Activity ◽  
Acid Content ◽  
Reference Strain ◽  
Vital Staining ◽  
Mycolic Acid ◽  
Viable Count ◽  
Mycolic Acids ◽  
Minimal Reduction

Settings. National Institute for Research in Tuberculosis, Chennai. Objective. To assess the proportion of metabolically active cells of Mycobacterium tuberculosis after exposed to CPC using FDA-EB vital staining and viable counts on LJ medium. Mycolic acid content in M. tuberculosis after exposure to CPC was estimated using HPLC. Methods. Clinical isolates of M. tuberculosis and standard reference strain M. tuberculosis H37Rv were used for FDA-EB, viable count, and HPLC. Results. FDA/EB consistently stained 70–90% of log phase cells as green and the remaining cells as red-orange. After CPC treatment, 65–70% of the cells stained red-orange. The viability counts were comparable to 0-day controls. Synthesis of mycolic acids in mycobacteria was reduced when exposed to CPC using HPLC due to the decreased metabolic activity of the organisms. Conclusion. The cells are metabolically inactive during storage with CPC but these cells grew well on LJ medium after removal of CPC. The viability of M. tuberculosis was maintained in CPC with minimal reduction. Mycolic acid content was reduced if the cells of M. tuberculosis were treated with CPC for 7 days. All the above findings provide yet another evidence for the damage of cell wall of M. tuberculosis.

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 Characterization of LtsA from Rhodococcus erythropolis, an Enzyme with Glutamine Amidotransferase Activity

2005 ◽  
Vol 187 (8) ◽  
pp. 2582-2591 ◽  
Author(s):  
Yasuo Mitani ◽  
XianYing Meng ◽  
Yoichi Kamagata ◽  
Tomohiro Tamura
Keyword(s):  
Cell Wall ◽  
Culture Media ◽  
Rhodococcus Erythropolis ◽  
Mycolic Acid ◽  
Site Directed Mutagenesis ◽  
Host Cells ◽  
Wall Structure ◽  
Synthetase Activity ◽  
Glutamine Amidotransferase ◽  
Glutaminase Activity

ABSTRACT The nocardioform actinomycete Rhodococcus erythropolis has a characteristic cell wall structure. The cell wall is composed of arabinogalactan and mycolic acid and is highly resistant to the cell wall-lytic activity of lysozyme (muramidase). In order to improve the isolation of recombinant proteins from R. erythropolis host cells (N. Nakashima and T. Tamura, Biotechnol. Bioeng. 86:136-148, 2004), we isolated two mutants, L-65 and L-88, which are susceptible to lysozyme treatment. The lysozyme sensitivity of the mutants was complemented by expression of Corynebacterium glutamicum ltsA, which codes for an enzyme with glutamine amidotransferase activity that results from coupling of two reactions (a glutaminase activity and a synthetase activity). The lysozyme sensitivity of the mutants was also complemented by ltsA homologues from Bacillus subtilis and Mycobacterium tuberculosis, but the homologues from Streptomyces coelicolor and Escherichia coli did not complement the sensitivity. This result suggests that only certain LtsA homologues can confer lysozyme resistance. Wild-type recombinant LtsA from R. erythropolis showed glutaminase activity, but the LtsA enzymes from the L-88 and L-65 mutants displayed drastically reduced activity. Interestingly, an ltsA disruptant mutant, which expressed the mutated LtsA, changed from lysozyme sensitive to lysozyme resistant when NH4Cl was added into the culture media. The glutaminase activity of the LtsA mutants inactivated by site-directed mutagenesis was also restored by addition of NH4Cl, indicating that NH3 can be used as an amide donor molecule. Taken together, these results suggest that LtsA is critically involved in mediating lysozyme resistance in R. erythropolis cells.

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 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 Two Accessory Proteins Govern MmpL3 Mycolic Acid Transport in Mycobacteria

mBio ◽  
2019 ◽  
Vol 10 (3) ◽  
Author(s):  
Allison Fay ◽  
Nadine Czudnochowski ◽  
Jeremy M. Rock ◽  
Jeffrey R. Johnson ◽  
Nevan J. Krogan ◽  
...  
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Cell Envelope ◽  
Complex Structure ◽  
Mycolic Acid ◽  
Accessory Proteins ◽  
Acid Transport ◽  
Content Type ◽  
Mycolic Acids ◽  
Antibiotic Target

ABSTRACT Mycolic acids are the signature lipid of mycobacteria and constitute an important physical component of the cell wall, a target of mycobacterium-specific antibiotics and a mediator of Mycobacterium tuberculosis pathogenesis. Mycolic acids are synthesized in the cytoplasm and are thought to be transported to the cell wall as a trehalose ester by the MmpL3 transporter, an antibiotic target for M. tuberculosis. However, the mechanism by which mycolate synthesis is coupled to transport, and the full MmpL3 transport machinery, is unknown. Here, we identify two new components of the MmpL3 transport machinery in mycobacteria. The protein encoded by MSMEG_0736/Rv0383c is essential for growth of Mycobacterium smegmatis and M. tuberculosis and is anchored to the cytoplasmic membrane, physically interacts with and colocalizes with MmpL3 in growing cells, and is required for trehalose monomycolate (TMM) transport to the cell wall. In light of these findings, we propose MSMEG_0736/Rv0383c be named “TMM transport factor A”, TtfA. The protein encoded by MSMEG_5308 also interacts with the MmpL3 complex but is nonessential for growth or TMM transport. However, MSMEG_5308 accumulates with inhibition of MmpL3-mediated TMM transport and stabilizes the MmpL3/TtfA complex, indicating that it may stabilize the transport system during stress. These studies identify two new components of the mycobacterial mycolate transport machinery, an emerging antibiotic target in M. tuberculosis. IMPORTANCE The cell envelope of Mycobacterium tuberculosis, the bacterium that causes the disease tuberculosis, is a complex structure composed of abundant lipids and glycolipids, including the signature lipid of these bacteria, mycolic acids. In this study, we identified two new components of the transport machinery that constructs this complex cell wall. These two accessory proteins are in a complex with the MmpL3 transporter. One of these proteins, TtfA, is required for mycolic acid transport and cell viability, whereas the other stabilizes the MmpL3 complex. These studies identify two new components of the essential cell envelope biosynthetic machinery in mycobacteria.

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.

Sign in / Sign up

Export Citation Format

Share Document