Search results for "Bacillus Subtilis"
showing 10 items of 70 documents
Cryptic Secondary Metabolites from the Sponge-Associated Fungus Aspergillus ochraceus
2019
The fungus Aspergillus ochraceus was isolated from the Mediterranean sponge Agelas oroides. The initial fermentation of the fungus on solid rice medium yielded 16 known compounds (4&ndash
Genetic and biochemical characterization by random and site-directed mutagenesis, repressors involved in stress response phenolic acids in Bacillus s…
2009
The aim of this work was to characterize the genetic and biochemical mechanisms involved in the PASR, the phenolic acid stress response induced by phenolic acids Bacillus subtilis. By genetics and molecular biology strategies, like reverse genetic, PCR or transposon random mutagenesis, gene deletion, complementation of strains, and gene expression, the main components of the PASR were identified and quantified. Site-directed and random mutagenesis of respectively the promoter of padC encoding the phenolic acid decaroxylase, and PadR, the repressor of the padC expression, allowed us to identify the site of binding of PadR with this promoter, as well as the amino-acid residues involved in the…
A supramolecular complex in the environmental stress signalling pathway of Bacillus subtilis
2003
SigmaB, an alternative sigma-factor of Bacillus subtilis, mediates the response of the cell to a variety of physical insults. Within the environmental stress signalling pathway RsbU, a protein phosphatase, is stimulated by its interaction with the protein kinase RsbT. In the absence of stress RsbT is expected to be trapped by an alternative binding partner, RsbS. Here, we have demonstrated that RsbS alone cannot act as an alternative partner for RsbT, but instead requires the presence of RsbR to create a high molecular mass RsbR:RsbS complex (approximately 1 MDa) able to capture RsbT. In this complex the phosphorylation state of RsbS, and not that of RsbR, controlled the binding to RsbT, wh…
Bax inhibitor-1 is likely a pH-sensitive calcium leak channel, not a H+/Ca2+ exchanger.
2014
The endoplasmic reticulum (ER) plays a key role in the synthesis, folding, and sorting of proteins, and disturbances of this delicate system can cause cell death. The ER also serves as the major intracellular calcium (Ca(2+)) store, and release of Ca(2+) from this store controls diverse cellular functions. At the interface of both these functions of the ER is Bax inhibitor-1 (BI-1), an evolutionarily conserved multifunctional protein that mediates Ca(2+) efflux from the ER and protects against ER stress. Several mechanisms have been proposed to explain how BI-1 might mediate Ca(2+) efflux from the ER. Chang et al. present structural evidence that a bacterial homolog of BI-1, BsYetJ, is a pH…
Proteomics of Galápagos Marine Iguanas Links Function of Femoral Gland Proteins to the Immune System
2020
Femoral glands secrete a wax-like substance on the inner side of lizard hind legs, which is thought to function as a mode of chemical communication. Though the minor volatile fraction is well studied, the major protein fraction remains enigmatic. Here, we use proteomics to analyze proteins in femoral gland secretions of the Galápagos marine iguana. Although we found no evidence for proteins and peptides involved in chemical communication, we found several immune-regulatory proteins which also demonstrate anti-microbial functions. Accordingly, we show that femoral gland proteins and peptides function as a barrier against microbial infection and may prevent the rapid degradation of volatile s…
Biologiczna kontrola Rhizoctonia solani AG 2-2IIIB przez metabolity Bacillus subtilis
2016
Celem doświadczenia było określenie aktywności metabolitów produkowanych przez bakteryjny szczep Bacillus subtilis wobec izolatu Rhizoctonia solani należącego do grupy AG 2-2IIIB. Antagonistyczne właściwości metabolitów B. subtilis były oceniane w kulturach płytkowych na podłożu Czapka po 6, 24 i 48 godzinach hodowli w temperaturze 30 i 37ºC. Wpływ metabolitów wytwarzanych przez B. subtilis na wzrost R. solani AG 2-2IIIB przedstawiono w postaci współczynnika tempa wzrostu liniowego grzyba. Uzyskane wyniki wykazały, że na fungistatyczną aktywność metabolitów B. subtilis wobec R. solani AG 2-2IIIB wpływa zarówno czas, jak i temperatura inkubacji bakterii. Wzrost grzybni był najmocniej hamowan…
Tonometers and infectious risk: myth or reality? Efficacy of different disinfection regimens on tonometer tips
2006
Purpose To evaluate the adequacy of common disinfection regimens for disposable tonometer tips and assess if disinfection of reusable prisms or the use of disposable tips is preferable. Methods We used disposable tonometer tips, using the same material and tip diameter of standard Goldmann tonometer prism. Strains of Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis and Candida albicans were tested according to the European standard guidelines for disinfectants test. Antimicrobial effectiveness of the following disinfection practices has been assessed: dry wipe, Minuten wipes (Alpros), soaking in 3% hydrogen peroxide, 0.5% benzalkonium chloride, and 0.5% Pantasepts for 1, 5, …
Uso del tonometro e rischio infettivo ; valutazione dell'efficacia di differenziali tipi di disinfettanti.
2006
Obiettivo: valutare e confrontare l’efficacia dei più comuni tipi di disinfettanti per la disinfezione dei coni tonometrici e trarre alcune indicazioni sulla applicabilità alla realtà clinico-diagnostica in campo oftalmologico. Materiali e metodi: coni tonometrici monouso sterili, previamente contaminati con ceppi standard di Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa e Candida albicans sono stati testati, dopo semplice detersione o disinfezione con acqua ossigenata al 3%, benzalconio cloruro allo 0.5%, Minuten wipes (Alpro® ), Pantasept® allo 0.5% secondo le linee guida del CDC di Atlanta. Risultati: la semplice detersione è stata inefficace contro tutte le specie tes…
Study of Bacillus subtilis spore's : characterication of stuctures implied in its resistance
2013
The bacterial spore is a multilayer microbial form which is extremely resistant to environmental perturbations. This resistance is especially due to its unique structure which is particularly compact and weakly permeable. This work aims to identify and characterize the spore structures involved in these properties. Overall investigation methods, such as NMR and fluorescence anisotropy, have shown that the cortex of Bacillus subtilis spores is modified by temperature for level similar to that of the activation of germination. This will result in changes to the access to the inner membrane. A tool at the spore’s scale, the fluorescence lifetime imaging microscopy (FLIM) in conjunction with th…
High gas pressure: An innovative method for the inactivation of dried bacterial spores
2012
In this article, an original non-thermal process to inactivate dehydrated bacterial spores is described. The use of gases such as nitrogen or argon as transmission media under high isostatic pressure led to an inactivation of over 2 logs CFU/g of Bacillus subtilis spores at 430 MPa, room temperature, for a 1 min treatment. A major requirement for the effectiveness of the process resided in the highly dehydrated state of the spores. Only a water activity below 0.3 led to substantial inactivation. The solubility of the gas in the lipid components of the spore and its diffusion properties was essential to inactivation. The main phenomenon involved seems to be the sorption of the gas under pres…