Search results for "biologia generale"
showing 10 items of 319 documents
Synthesis and anti-staphylococcal activity of new 4-diazopyrazole derivatives.
2012
Abstract Several new 4-diazopyrazole derivatives 6a – g and 9a – c were obtained by the reaction of 1-(R-substituted-phenyl)-3-(1,3-dimethyl-1 H -pyrazol-5-yl)ureas 5a – g and N -(1,3-dimethyl-1 H -pyrazol-5-yl)-2-(R-substituted-phenyl)acetamides 8a – c respectively with a sevenfold excess of nitrous acid in acetic acid solution. The compounds were assayed for their activity against the Staphylococcus aureus reference strains ATCC 25923, ATCC 29213 and ATCC 6538, as well as six veterinary strains. The best anti-staphylococcal profile was showed by [(R-substituted-phenyl)acetyl](4-diazonio-1,3-dimethyl-1 H -pyrazol-5-yl)azanides 9a , c . Compound 9c was also able at 3.1 μg mL −1 to inhibit o…
Phosphate-controlled regulator for the biosynthesis of the dalbavancin precursor A40926
2008
Endophytes from Phragmites australis: their role in phytodepuration
Wastewater treatment is an alarming question and phytodepuration represents an efficient and cost-effective solution. Phragmites australis is generally used for phytodepuration and it excellently removes arsenic, iron and nickel from polluted water. The purification potential of its bacterial endophytic community has never been explored though. G.I.D.A. S.p.a uses P. australis for phytoremediation in a pilot plant, at Calice purifier, which treats the effluent from the Membrane Bioreactor plant. Endophytic bacterial strains were isolated from different P. australis compartments sampled before the activation of the Calice purifier and four additional times during a 18-months period, to analy…
Invasional meltdown via horizontal gene transfer of a European symbiosis island variant in North American nodule symbionts of Cytisus scoparius
2022
New data from sites in Spain, Sicily and North America establish that the spread of the European legume Cytisus scoparius (Scotch broom) across North America involved the concurrent invasion of a European mobile genetic element (symbiosis island [SI]) into North American Bradyrhizobium nodule bacteria. At four SI loci, bacteria from nine C. scoparius populations across the continent were all identical to haplotypes present in European Bradyrhizobium strains. At seven non-symbiotic (housekeeping) loci, these American C. scoparius bacteria grouped into eight diverse lineages related to, or in some cases identical to, symbionts from several native North American legumes. Inoculation experiment…
Synthesis and antioproliferative activity of new derivatives containing the policyclic sistem 5,7:7,13-dimethanopyrazolo[3,4-b]pyrazolo[3'.4':2,3]aze…
2012
By reacting methylaminopyrazoles with hexane-2,5-dione in 1,4-dioxane in the presence of p-toluensulfonic acid, new derivatives containing the policyclic sistem 5,7:7,13-dimethanopyrazolo[3,4-b]pyrazolo[3'.4':2,3]azepino[4,5-f]azocine were obtained. The new synthesized compounds were tested preliminarly at 10 microM against five human cancer cell lines showing a range of inhibition of 20-62% against the most susceptible cell lines K562 and HCT116.
Cross-linked natural IntegroPectin films from citrus biowaste with intrinsic antimicrobial activity
2022
AbstractPectin recovered via hydrodynamic cavitation (IntegroPectin) from lemon and grapefruit agri-food waste intrinsically containing antimicrobial bioactive substances (flavonoids, phenolic acids, terpenes, and terpenoids) was used to generate innovative and eco-compatible films that efficiently inhibit the growth of Gram-negative pathogens. Extensive characterization of films confirmed the presence of these substances, which differently interact with the polysaccharide polymer (pectin), plasticizer (glycerol), surfactant (Tween 60), and cross-linker (Ca2+), conferring to these films a unique structure. Besides, IntegroPectin-based films constitute versatile systems for the sustained, co…
High diversity of root endophytes in the pioneer endemic Betula aetnensis Raf. colonizing volcanic lavas
2019
Introduction Betula aetnensis Raf. is an endemic tree species native to Sicily of particular conservation value, that establishes on nutrient-poor and water-limited lava of Etna volcano. In these harsh conditions plant-microbe interactions could play a crucial role in plant growth, resource uptake and resistance to abiotic stresses. The aim of this study is to investigate the root-associated microbial community of B. aetnensis growing in its natural habitat. The comparison between individuals from natural habitats and nursery-grown seedlings aims to assess the symbiotic status of plant material used for afforestation purposes. Materials and Methods Betula aetnensis individuals were collecte…
Production of Antibacterial Compounds from Actinomycetes
2016
Actinomycetes are soil-dwelling Gram-positive bacteria, industrially relevant as producers of a wide range of bioactive secondary metabolites, including many antibiotics of clinical and commercial importance.The understanding of actinomycete biology has been based on extensive studies on the model organism Streptomyces coelicolor over many years and on the availability of its complete genome sequence. This bacterium has an unusual complex developmental cycle that includes programmed cell death phenomena that make this bacterium a multicellular prokaryotic model.Morphological differentiation in S. coelicolor is strictly related to physiological differentiation: indeed the onset of morphologi…