0000000000345941

AUTHOR

A. Vassallo

showing 8 related works from this author

Characterization of the bacterial community isolated from a High Middle Age soil sample dated since 980 AD

2016

Paleomicrobiology ancient samples bacterial community antibiotics secreted proteasesSettore BIO/19 - Microbiologia Generale
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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…

Phragmites australiEndophytesWastewater treatmentSettore BIO/19 - Microbiologia Generale
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trpX: a small orf involved in S. coelicolor tryptophan metabolism

2013

Streptomyces coelicolor small orf tryptophan metabolismSettore BIO/19 - Microbiologia Generale
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THE SMALL PROTEIN TRPM MODULATES MORPHO-PHYSIOLOGICAL DIFFERENTIATION IN THE MODEL ACTINOMYCETE STREPTOMYCES COELICOLOR A3(2)

2017

BACKGROUNDS TrpM, a small protein of 63 amino acids, modulates tryptophan (Trp) metabolism and morpho-physiological differentiation in the filamentous bacterium Streptomyces coelicolor A3(2), a model organism for antibiotic production and cell differentiation. Indeed, the trpM knock-out mutant strain is characterized by a delayed growth on minimal medium, smaller aerial hyphae, and reduction of both spore and antibiotic actinorhodin production in comparison with the wild-type strain. These observations were in agreement with proteomic analyses which highlighted a role for TrpM in controlling i) Trp production through Trp precursor availability and, thus ii) bacterial growth and morpho-physi…

Streptomyces coelicolor antibiotic production morpho-physiological differentiationSettore BIO/19 - Microbiologia Generale
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The small protein TrpM modulates morpho-physiological differentiation in Streptomyces coelicolor

2017

TrpM, a small protein of 63 amino acids, is encoded by a gene of the trpCMBA locus involved in tryptophan biosynthesis in the model actinomycete Streptomyces coelicolor. Indeed, the trpM knock-out mutant strain is characterized by a delayed growth on minimal medium, smaller aerial hyphae, and reduction of both spore and antibiotic actinorhodin production in comparison with the wild-type strain. These observations are in agreement with proteomic analyses which highlighted a role for TrpM in controlling i) tryptophan production through precursor availability and, thus ii) bacterial growth and morpho-physiological differentiation. To further elucidate the role of TrpM, a S. coelicolor trpM kno…

Streptomyces coelicolor antibiotic production morpho-physiological differentiationSettore BIO/19 - Microbiologia Generale
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The small protein SCO2038 modulates tryptophan biosynthesis and morpho-physiological differentiation in Streptomyces coelicolor

2016

In Streptomyces coelicolor small open reading frames were identified in several amino acids biosynthetic gene clusters, like SCO2038 (trpX) in the tryptophan trpCXBA locus. Here, the role of SCO2038, encoding a 63 amino acid protein, was investigated by both phenotypic and molecular analyses. A SCO2038 knockout mutant strain showed a delayed growth on minimal medium (MM), compromised actinorhodin biosynthesis and poor sporulation. The capability of this mutant to grow on MM was restored by tryptophan’s and its precursors’ supplementation. Pulldown and bacterial two hybrid assays revealed SCO2038 interaction with PepA, which is putatively involved in the metabolism of serine, glycine and cys…

tryptophan gene clusteractinorhodin productionmorphophysiological differentiation
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Compartmentalization of biosynthetic enzymes in bacterial cells: the histidine metabolic pathway case

Introduction: It is known that the inner concentration of proteins within the cell cytoplasm is so high that limits the diffusion of enzymes and metabolic intermediates, leading to a loss of time and energy. Therefore, the organization of genes in operons would have enabled to have enzymes involved in the same metabolic pathway physically close to each other. A corollary to this hypothesis in the possibility of physical interactions between the enzymes of the same metabolic pathway, resulting in the formation of a supramolecular complex capable in channeling the intermediates from one enzyme to a physical adjacent one, with restricted diffusion in the surrounding milieu. Objectives: The aim…

BACTHHistidine biosynthesiSettore BIO/19 - Microbiologia Generale
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Quark model predictions for the SU(6)-breaking ratio of the proton momentum distributions

2003

The ratio between the anomalous magnetic moments of proton and neutron has been recently parametrized by the ratio of proton momentum fractions $M_{2}^{q_{val}}$. This ratio is evaluated using different constituent quark models, starting from the CQM density distributions and calculating the next-to leading order distributions. We show that this momentum fractions $M_{2}^{q_{val}}$ ratio is a sensitive test for SU(6)-breaking effects and therefore it is useful to distinguish among different CQMs. We investigate also the possibility of getting constraints on the formulation of quark structure models.

PhysicsQuarkNuclear and High Energy PhysicsParticle physicsNuclear TheoryProtonMagnetic momentParton distributionsNuclear TheoryQuark modelFOS: Physical sciencesConstituent quarkOrder (ring theory)Constituent quark modelsHadronsNuclear Theory (nucl-th)MomentumSU(6)PartonsPhysics Letters B
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