Search results for "IBA"

Isolation, purification and antibacterial effects of fusaproliferin produced by Fusariumsubglutinans in submerged culture.

2009

To evaluate the fusaproliferin (FUS) production, Fusariumsubglutinans ITEM 2404 was grown in a liquid medium of potato being this mycotoxin purified by high-performance liquid chromatography (HPLC) with a C18 semipreparative column using a mobile phase of acetonitrile/H(2)O using gradient conditions. The purity of the fusaproliferin was verified by analytical HPLC, ultraviolet absorbance measurements, LC/MS-MS, (1)H NMR spectroscopy. The isolated FUS was shown to be free of impurities and can be used as a standard for routine analysis. The pure fusaproliferin was utilized to study the biological activity on Escherichiacoli and Staphylococcusaureus. This study demostred that FUS not showed s…

Antibacterial activity of the emerging Fusarium mycotoxins enniatins A, A1, A2, B, B1, and B4 on probiotic microorganisms

2014

Abstract Enniatins (ENs) are secondary metabolites produced by several Fusarium strains, chemically characterized as N-methylated cyclohexadepsipeptides. These compounds are known to act as antifungal and antibacterial agents, but they also possess anti-insect and phytotoxic properties. In this study, the antimicrobial effect of pure fractions of the bioactive compounds ENs A, A 1 , A 2 , B, B 1 , and B 4 was tested towards nine probiotic microrganisms, twenty-two Saccharomyces cerevisiae strains and nine Bacillus subtilis strains. Antimicrobial analyses were carried out the disc-diffusion method using ENs concentrations ranging from 0.2 to 20,000 ng. Plates were incubated for 24 h at 37 °C…

The Cell Cycle-Specific Growth-Inhibitory Factor Produced by Actinobacillus actinomycetemcomitans Is a Cytolethal Distending Toxin

1998

ABSTRACT Actinobacillus actinomycetemcomitans has been shown to produce a soluble cytotoxic factor(s) distinct from leukotoxin. We have identified in A. actinomycetemcomitans Y4 a cluster of genes encoding a cytolethal distending toxin (CDT). This new member of the CDT family is similar to the CDT produced by Haemophilus ducreyi . The CDT from A. actinomycetemcomitans was produced in Escherichia coli and was able to induce cell distension, growth arrest in G 2 /M phase, nucleus swelling, and chromatin fragmentation in HeLa cells. The three proteins, CDTA, -B and -C, encoded by the cdt locus were all required for toxin activity. Antiserum raised against recombinant CDTC completely inhibited …

STRATEGIE PER IL MIGLIORAMENTO DELLA PRODUZIONE E LO SVILUPPO DI MOLECOLE AD ATTIVITÀ ANTIBIOTICA DI ORIGINE NATURALE O DI SINTESI CHIMICA

The emergence of multi-drug resistant (MDR) bacterial strains is an urgent problem derived from the widespread and uncontrolled use of antibiotics. Therefore, new arrays of lead compounds exerting antimicrobial activity are necessary to contrast the spreading of MDR pathogens. Between 1980 and 2003, the interest in scientific research programs aimed to the new drug discovery by large pharmaceutical companies progressively decreased due to increasing costs in the respect of i) the low discovery rate of new leads, ii) the small amounts of product recovery needing process optimization and, finally, iii) regulatory obstacles associated with long-lasting pre-clinical and clinical trials for ther…

Phosphate-controlled regulator for the biosynthesis of the dalbavancin precursor A40926

2007

ABSTRACT The actinomycete Nonomuraea sp. strain ATCC 39727 produces the glycopeptide A40926, the precursor of the novel antibiotic dalbavancin. Previous studies have shown that phosphate limitation results in enhanced A40926 production. The A40926 biosynthetic gene ( dbv ) cluster, which consists of 37 genes, encodes two putative regulators, Dbv3 and Dbv4, as well as the response regulator (Dbv6) and the sensor-kinase (Dbv22) of a putative two-component system. Reverse transcription-PCR (RT-PCR) and real-time RT-PCR analysis revealed that the dbv14 - dbv8 and the dbv30 - dbv35 operons, as well as dbv4 , were negatively influenced by phosphate. Dbv4 shows a putative helix-turn-helix DNA-bind…

Antimicrobial and Insecticidal: Cyclic Lipopeptides and Hydrogen Cyanide Produced by Plant-Beneficial Pseudomonas Strains CHA0, CMR12a, and PCL1391 C…

2017

Particular groups of plant-beneficial fluorescent pseudomonads are not only root colonizers that provide plant disease suppression, but in addition are able to infect and kill insect larvae. The mechanisms by which the bacteria manage to infest this alternative host, to overcome its immune system, and to ultimately kill the insect are still largely unknown. However, the investigation of the few virulence factors discovered so far, points to a highly multifactorial nature of insecticidal activity. Antimicrobial compounds produced by fluorescent pseudomonads are effective weapons against a vast diversity of organisms such as fungi, oomycetes, nematodes, and protozoa. Here, we investigated whe…

Tommaso Salvini 1860: Fortinbras come Garibaldi al Teatro dei Fiorentini di Napoli

2021

Garibaldi landed in Marsala on 11 May 1860. In July of the same year, the Thousand were still fighting in Sicily with the aim of reaching Calabria, where they would have arrived on 1 August, and from there marched to Naples. And on the very evening of 14 July, on the stage of Florentines theatre in Naples, the leading actor Tommaso Salvini (1829-1915) presented a mutilated Hamlet, deprived above all of the most introspective and sentimental scenes, whose interpretation is still preserved in his prompt-book of Hamlet. The declamatory symbols marked by Salvini are still readable in the prompt-book of his 1860 interpretation that is now housed at the Museo Biblioteca dell’Attore, in Genoa. Und…

Il riposo del Generale

2009

Un "personaggio" dell'epopea garibaldina francese: fra' Giovanni Pantaleo

2006

L’impresa dei Mille aveva portato a compimento, fra luci e ombre messe in rilievo dalla storiografia dei nostri giorni, la liberazione di una terra ch’è sempre stata e continua ad essere, per i Francesi, la mitica “Île du Soleil”. Principale responsabile dell’immediata diffusione del mito garibaldino fu Alexandre Dumas, che pubblicò ad immediato ridosso della felice conclusione dell’impresa dei Mille Les Garibaldiens, una sorta di taccuino su quella spedizione, ricostruita nel suo dipanarsi dal momento dell’imbarco a Quarto e fino alla caduta di Napoli. Quel testo ha contribuito in modo non indifferente a diffondere sempre di più in Francia, rafforzandolo, il mito che avvolgeva ormai, dopo …

Contribution of insertions and deletions to the variability of hepatitis C virus populations

2007

Little is known about the potential effects of insertions and deletions (indels) on the evolutionary dynamics of hepatitis C virus (HCV). In fact, the consequences of indels on antiviral treatment response are a field of investigation completely unexplored. Here, an extensive sequencing project was undertaken by cloning and sequencing serum samples from 25 patients infected with HCV subtype 1a and 48 patients with subtype 1b. For 23 patients, samples obtained after treatment with alpha interferon plus ribavirin were also available. Two genome fragments containing the hypervariable regions in the envelope 2 glycoprotein and the PKR-BD domain in NS5A were sequenced, yielding almost 16 000 seq…