Search results for "biologia generale"

Differential proteomic analysis highlights metabolic strategies associated with balhimycin production in Amycolatopsis balhimycina chemostat cultivat…

2010

Abstract Background Proteomics was recently used to reveal enzymes whose expression is associated with the production of the glycopeptide antibiotic balhimycin in Amycolatopsis balhimycina batch cultivations. Combining chemostat fermentation technology, where cells proliferate with constant parameters in a highly reproducible steady-state, and differential proteomics, the relationships between physiological status and metabolic pathways during antibiotic producing and non-producing conditions could be highlighted. Results Two minimal defined media, one with low Pi (0.6 mM; LP) and proficient glucose (12 g/l) concentrations and the other one with high Pi (1.8 mM) and limiting (6 g/l; LG) glu…

TrpM, a Small Protein Modulating Tryptophan Biosynthesis and Morpho-Physiological Differentiation in Streptomyces coelicolor A3(2).

2016

In the model actinomycete Streptomyces coelicolor A3(2), small open reading frames encoding proteins with unknown functions were identified in several amino acid biosynthetic gene operons, such as SCO2038 (trpX) in the tryptophan trpCXBA locus. In this study, the role of the corresponding protein in tryptophan biosynthesis was investigated by combining phenotypic and molecular analyses. The 2038KO mutant strain was characterized by delayed growth, smaller aerial hyphae and reduced production of spores and actinorhodin antibiotic, with respect to the WT strain. The capability of this mutant to grow on minimal medium was rescued by tryptophan and tryptophan precursor (serine and/or indole) su…

Differential proteomic analysis of an engineered Streptomyces coelicolor strain reveals metabolic pathways supporting growth on n-hexadecane

2012

The alkB gene, encoding an alkane monooxygenase in the actinomycete Gordonia sp. SoCg, was expressed in the non-alkane-degrading actinomycete Streptomyces coelicolor M145. The resulting engineered strain, M145-AH, can grow on n-hexadecane as sole carbon source. To unravel proteins associated with growth on n-alkanes, proteome of M145-AH after 6, 24, and 48 h of incubation in the Bushnell-Haas (BH) mineral medium containing n-hexadecane as sole carbon source (H condition) and in BH without any carbon source (0 condition) were compared using 2D-differential gel electrophoresis. Proteome analysis revealed significant changes only at 48 h, showing 48 differentially abundant proteins identified …

Differential proteomic analysis reveals novel links between primary metabolism and antibiotic production in Amycolatopsis balhimycina.

2010

A differential proteomic analysis, based on 2-DE and MS procedures, was performed on Amycolatopsis balhimycina DSM5908, the actinomycete producing the vancomycin-like antibiotic balhimycin. A comparison of proteomic profiles before and during balhimycin production characterized differentially and constitutively expressed protein isoforms, which were associated to 203 ORFs in the A. balhimycina genome. These data, providing insights on the major metabolic pathways/molecular processes operating in this organism, were used to compile 2-DE reference maps covering 3-10, 4-7 and 4.5-5.5 pH gradients available over the World Wide Web as interactive web pages (http://www.unipa.it/ampuglia/Abal-prot…

Adaptative biochemical pathways and regulatory networks in Klebsiella oxytoca BAS-10 producing a biotechnologically relevant exopolysaccharide during…

2012

Abstract Background A bacterial strain previously isolated from pyrite mine drainage and named BAS-10 was tentatively identified as Klebsiella oxytoca. Unlikely other enterobacteria, BAS-10 is able to grow on Fe(III)-citrate as sole carbon and energy source, yielding acetic acid and CO2 coupled with Fe(III) reduction to Fe(II) and showing unusual physiological characteristics. In fact, under this growth condition, BAS-10 produces an exopolysaccharide (EPS) having a high rhamnose content and metal-binding properties, whose biotechnological applications were proven as very relevant. Results Further phylogenetic analysis, based on 16S rDNA sequence, definitively confirmed that BAS-10 belongs t…

Polyanion–tobramycin nanocomplexes into functional microparticles for the treatment of Pseudomonas aeruginosa infections in cystic fibrosis

2016

Aim: Efficacy of antibiotics in cystic fibrosis (CF) is compromised by the poor penetration through mucus barrier. This work proposes a new ‘nano-into-micro’ approach, used to obtain a combinatorial effect: achieve a sustained delivery of tobramycin and overcome mucus barrier. Methods: Mannitol microparticles (MPs) were loaded with a tobramycin polymeric nanocomplex and characterized in presence of CF artificial mucus. Results & discussion: MPs are able to alter the rheological properties of CF artificial mucus, enhancing drug penetration into it and allowing a prolonged drug release. MPs resulted to be effective in Pseudomonas aeruginosa infections if compared with free tobramycin. Co…

Natural peptides as scaffold for synthetic antibiofilm and antimicrobial peptides (SAAMPs) useful to control antimicrobial resistance spreading

Pharmaceutical potential of synthetic and natural pyrrolomycins

2015

The emergence of antibiotic resistance is currently considered one of the most important global health problem. The continuous onset of multidrug-resistant Gram-positive and Gram-negative bacterial strains limits the clinical efficacy of most of the marketed antibiotics. Therefore, there is an urgent need for new antibiotics. Pyrrolomycins are a class of biologically active compounds that exhibit a broad spectrum of biological activities, including antibacterial, antifungal, anthelmintic, antiproliferative, insecticidal, and acaricidal activities. In this review we focus on the antibacterial activity and antibiofilm activity of pyrrolomycins against Gram-positive and Gram-negative pathogens…

Regulation of the biosynthesis of the dalbavancin precursor A40926

2008

Analisi della comunità microbica intestinale di Reticulitermes lucifugus (Rossi) (Isoptera: Rhinotermitidae).

2009

L’intestino delle termiti ospita una comunità microbica di batteri e flagellati anaerobi, responsabile della degradazione del materiale lignocellulosico. La digestione della lignocellulosa da parte delle termiti dipende dalla simbiosi con microrganismi procarioti ed eucarioti che vivono nel loro intestino. I microrganismi trasformano la cellulosa in zuccheri e acetato, producendo idrogeno, metano e anidride carbonica. Abbiamo analizzato la comunità microbica intestinale di Reticulitermes lucifugus lucifugus, una delle due specie di termiti italiane, che vive in ambienti sotterranei, è distruttiva per le strutture legnose degli ambienti urbani causando seri danni ai monumenti storici e può c…