scholarly journals Effect of Penicillin on the In Vivo Formation of the D-Alanyl-L-Alanine Peptide Cross-Linkage in Cell Walls of Micrococcus luteus

1974 ◽  
Vol 5 (6) ◽  
pp. 663-666 ◽  
Author(s):  
D. Mirelman ◽  
R. Bracha
Keyword(s):  
Cell Walls ◽  
Micrococcus Luteus ◽  
Cross Linkage

Varying influence of the autolysin, N-acetyl muramidase, and the cell envelope proteinase on the rate of autolysis of six commercial Lactococcus lactis cheese starter bacteria grown in milk

2000 ◽  
Vol 67 (4) ◽  
pp. 585-596 ◽  
Author(s):  
SELVARANI GOVINDASAMY-LUCEY ◽  
PRAMOD K. GOPAL ◽  
PATRICK A. SULLIVAN ◽  
CHRISTOPHER J. PILLIDGE
Keyword(s):  
Lactococcus Lactis ◽  
Cell Walls ◽  
Cell Envelope ◽  
Laboratory Strain ◽  
Proteolytic Cleavage ◽  
Zymogram Analysis ◽  
Sds Page ◽  
Derivatives Of ◽  
Free Strains

The autolysin, N-acetyl muramidase (AcmA), of six commercial Lactococcus lactis subsp. cremoris starter strains and eight Lc. lactis subsp. cremoris derivatives or plasmid-free strains was shown by renaturing SDS-PAGE (zymogram analysis) to be degraded by the cell envelope proteinase (lactocepin; EC 3.4.21.96) after growth of strains in milk at 30 °C for 72 h. Degradation of AcmA was less in starter strains and derivatives producing lactocepin I/III (intermediate specificity) than in strains producing lactocepin I. This supports previous observations on AcmA degradation in derivatives of the laboratory strain Lc. lactis subsp. cremoris MG1363 (Buist et al. Journal of Bacteriology180 5947–5953 1998). In contrast to the MG1363 derivatives, however, the extent of autolysis in milk of the commercial Lc. lactis subsp. cremoris starter strains in this study did not always correlate with lactocepin specificity and AcmA degradation. The distribution of autolysins within the cell envelope of Lc. lactis subsp. cremoris starter strains and derivatives harvested during growth in milk was compared by zymogram analysis. AcmA was found associated with cell membranes as well as cell walls and some cleavage of AcmA occurred independently of lactocepin activity. An AcmA product intermediate in size between precursor (46 kDa) and mature (41 kDa) forms of AcmA was clearly visible on zymograms, even in the absence of lactocepin I activity. These results show that autolysis of commercial Lc. lactis subsp. cremoris starter strains is not primarily determined by AcmA activity in relation to lactocepin specificity and that proteolytic cleavage of AcmA in vivo is not fully defined.

In vivo Role of the UV-Endonuclease from Micrococcus luteus in the Repair of DNA

1971 ◽  
Vol 234 (45) ◽  
pp. 47-50 ◽  
Author(s):  
INGA MAHLER ◽  
SIDNEY R. KUSHNER ◽  
LAWRENCE GROSSMAN
Keyword(s):  
Micrococcus Luteus

scholarly journals Individual Mycobacterium tuberculosis Resuscitation-Promoting Factor Homologues Are Dispensable for Growth In Vitro and In Vivo

2004 ◽  
Vol 72 (1) ◽  
pp. 515-526 ◽  
Author(s):  
JoAnn M. Tufariello ◽  
William R. Jacobs, ◽  
John Chan
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Stationary Phase ◽  
Essential Gene ◽  
Micrococcus Luteus ◽  
Expression Patterns ◽  
Active Growth ◽  
Prolonged Incubation ◽  
Aerosol Infection

ABSTRACT Mycobacterium tuberculosis possesses five genes with significant homology to the resuscitation-promoting factor (Rpf) of Micrococcus luteus. The M. luteus Rpf is a secreted ∼16-kDa protein which restores active growth to cultures of M. luteus rendered dormant by prolonged incubation in stationary phase. More recently, the Rpf-like proteins of M. tuberculosis have been shown to stimulate the growth of extended-stationary-phase cultures of Mycobacterium bovis BCG. These data suggest that the Rpf proteins can influence the growth of mycobacteria; however, the studies do not demonstrate specific functions for the various members of this protein family, nor do they assess the function of M. tuberculosis Rpf homologues in vivo. To address these questions, we have disrupted each of the five rpf-like genes in M. tuberculosis Erdman, and analyzed the mutants for their growth in vitro and in vivo. In contrast to M. luteus, for which rpf is an essential gene, we find that all of the M. tuberculosis rpf deletion mutant strains are viable; in addition, all show growth kinetics similar to Erdman wild type both in vitro and in mouse organs following aerosol infection. Analysis of rpf expression in M. tuberculosis cultures from early log phase through late stationary phase indicates that expression of the rpf-like genes is growth phase-dependent, and that the expression patterns of the five M. tuberculosis rpf genes, while overlapping to various degrees, are not uniform. We also provide evidence that mycobacterial rpf genes are expressed in vivo in the lungs of mice acutely infected with virulent M. tuberculosis.

scholarly journals PHYTOCHEMICAL INVESTIGATION, GC-MS PROFILE AND ANTIMICROBIAL ACTIVITY OF A MEDICINAL PLANT RUTA GRAVEOLENS L. FROM ETHIOPIA

2017 ◽  
Vol 9 (6) ◽  
pp. 29 ◽  
Author(s):  
Henok Gulilat Azalework ◽  
Sahabjada . ◽  
Asif Jafri ◽  
Md Arshad ◽  
Tabarak Malik
Keyword(s):  
Secondary Metabolites ◽  
Leaf Extract ◽  
Micrococcus Luteus ◽  
Biological Activities ◽  
Antimicrobial Effect ◽  
Phytochemical Analysis ◽  
Ruta Graveolens ◽  
Zone Of Inhibition ◽  
Ms Analysis

Objective: This study was designed to screen the phytochemicals present in various solvents extracts of Ruta graveolens (Rue) and furthermore to investigate their antimicrobial activity.Methods: The leaves, stems and seeds of Rue were extracted using four different solvents viz. ethanolic, methanolic, chloroform, and aqueous of varying polarity. The phytochemical screening was carried out qualitatively and Gas Chromatography-Mass Spectroscopy (GC-MS) analysis was performed to identify major phytoconstituents present in the methanolic leaf extract. The antimicrobial effect of extracts was evaluated against six microbial strains namely Bacillus subtillis, Escherichia coli, Proteus vulgaris, Candida albicans, Candida tropicalis and Micrococcus luteus with disc diffusion method.Results: Phytochemical analysis revealed the presence of various secondary metabolites such as flavonoids, alkaloids, terpenoids, saponins and carotenoid. The methanolic leaf extract showed the presence of both tannin and phenolic contents in the higher amount, whereas aqueous extract displayed in the least amount. GC-MS analysis of methanolic leaf extract revealed the presence of approximately 26 phytochemical constituents. The antimicrobial assay revealed that B. subtilis showed a high zone of inhibition (20 mm) at 200 mg/ml of methanolic extract. However, E. coli and C. tropicalis did not show any zone of inhibition against each solvent extract.Conclusion: In conclusion, secondary metabolites present in the extracts have biological activities which warrant further to evaluate in vivo pharmacological studies.

scholarly journals Anti-Invasion and Antiangiogenic Effects of Stellettin B through Inhibition of the Akt/Girdin Signaling Pathway and VEGF in Glioblastoma Cells

Cancers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 220 ◽  
Author(s):  
Shu-Yu Cheng ◽  
Nan-Fu Chen ◽  
Pi-Yu Lin ◽  
Jui-Hsin Su ◽  
Bing-Hung Chen ◽  
...  
Keyword(s):  
Umbilical Vein ◽  
Mammalian Target Of Rapamycin ◽  
Metastatic Potential ◽  
Filamentous Actin ◽  
Glioblastoma Cells ◽  
Tubule Formation ◽  
Recurrence Prediction ◽  
Cross Linkage ◽  
Umbilical Vein Endothelial Cells

Angiogenesis and invasion are highly related with tumor metastatic potential and recurrence prediction in the most aggressive brain cancer, glioblastoma multiforme (GBM). For the first time, this study reveals that marine-sponge-derived stellettin B reduces angiogenesis and invasion. We discovered that stellettin B reduces migration of glioblastoma cells by scratch wound healing assay and invasion via chamber transwell assay. Further, stellettin B downregulates Akt/Mammalian Target of Rapamycin (Akt/mTOR) and Signal transducer and activator of transcription 3 (Stat3) signaling pathways, which are essential for invasion and angiogenesis in glioblastoma. This study further demonstrates that stellettin B affects filamentous actin (F-actin) rearrangement by decreasing the cross-linkage of phosphor-Girdin (p-Girdin), which attenuates glioblastoma cell invasion. Moreover, stellettin B blocks the expression and secretion of a major proangiogenic factor, vascular endothelial growth factor (VEGF), in glioblastoma cells. Stellettin B also reduces angiogenic tubule formation in human umbilical vein endothelial cells (HUVECs). In vivo, we observed that stellettin B decreased blood vesicle formation in developmental zebrafish and suppressed angiogenesis in Matrigel plug transplant assay in mice. Decreased VEGF transcriptional expression was also found in stellettin B–treated zebrafish embryos. Overall, we conclude that stellettin B might be a potential antiangiogenic and anti-invasion agent for future development of therapeutic agents for cancer therapy.

scholarly journals Micrococcus luteus Teichuronic Acids Activate Human and Murine Monocytic Cells in a CD14- and Toll-Like Receptor 4-Dependent Manner

2001 ◽  
Vol 69 (4) ◽  
pp. 2025-2030 ◽  
Author(s):  
Shuhua Yang ◽  
Shunji Sugawara ◽  
Toshihiko Monodane ◽  
Masahiro Nishijima ◽  
Yoshiyuki Adachi ◽  
...  
Keyword(s):  
Lipid A ◽  
Micrococcus Luteus ◽  
Dependent Manner ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Necrosis Factor Alpha ◽  
Monocytic Cells ◽  
Tnf Α

ABSTRACT Teichuronic acid (TUA), a component of the cell walls of the gram-positive organism Micrococcus luteus (formerlyMicrococcus lysodeikticus), induced inflammatory cytokines in C3H/HeN mice but not in lipopolysaccharide (LPS)-resistant C3H/HeJ mice that have a defect in the Toll-like receptor 4 (TLR4) gene, both in vivo and in vitro, similarly to LPS (T. Monodane, Y. Kawabata, S. Yang, S. Hase, and H. Takada, J. Med. Microbiol. 50:4–12, 2001). In this study, we found that purified TUA (p-TUA) induced tumor necrosis factor alpha (TNF-α) in murine monocytic J774.1 cells but not in mutant LR-9 cells expressing membrane CD14 at a lower level than the parent J774.1 cells. The TNF-α-inducing activity of p-TUA in J774.1 cells was completely inhibited by anti-mouse CD14 monoclonal antibody (MAb). p-TUA also induced interleukin-8 (IL-8) in human monocytic THP-1 cells differentiated to macrophage-like cells expressing CD14. Anti-human CD14 MAb, anti-human TLR4 MAb, and synthetic lipid A precursor IVA, an LPS antagonist, almost completely inhibited the IL-8-inducing ability of p-TUA, as well as LPS, in the differentiated THP-1 cells. Reduced p-TUA did not exhibit any activities in J774.1 or THP-1 cells. These findings strongly suggested that M. luteus TUA activates murine and human monocytic cells in a CD14- and TLR4-dependent manner, similar to LPS.

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