Search results for " microbiologia"

Monitoraggio del ceppo starter Lactobacillus pentosus OM13 nella fermentazione delle olive da tavola (cv. “Nocellara del Belice”) con lavorazione siv…

2014

Obiettivo di questa ricerca . stato validare le attitudini tecnologiche alla trasformazione di olive da mensa cv. “Nocellara del Belice” da parte del ceppo Lactobacillus pentosus OM13. Lo starter Lb. pentosus OM13 ha dimostrato di dominare l’intero processo fermentativo e ha determinato un sensibile abbassamento del pH, inibendo cos. lo sviluppo di microrganismi potenzialmente patogeni e/o alterativi. All’inizio della sperimentazione e fino al 16¢X giorno di fermentazione, i lieviti hanno mostrato un incremento in entrambe le lavorazioni, con starter e di controllo, ma con un livello di carica microbica maggiore nella tesi di controllo. Nella fase di sperimentazione, successiva al 16¢X gior…

Effect of Three Different Aloe vera Gel-Based Edible Coatings on the Quality of Fresh-Cut “Hayward” Kiwifruits

2020

In recent years, the market for minimally processed fruit has increased. Fresh-cut fruits are characterized by a short shelf life due to the processing phases that accelerate the ripening courses. The aim of this work is to analyze the effect on the quality of fresh-cut Hayward kiwis of three different edible coatings based on (1) Aloe vera gel, (2) Aloe vera gel + hydroxypropyl methylcellulose and (3) Aloe vera gel + lemon essential oil. Fruit firmness, weight loss, color, soluble solids content, titratable acidity, microbial load and sensory analysis were evaluated as fresh after 2, 4, 7 and 10 days. Aloe vera gel and Aloe vera gel + lemon essential oil maintained the best values, as they…

Microbial strategies to improve the final quality of traditional Sicilian cheeses

Polyphasic Characterization of Microbiota of “Mastredda”, a Traditional Wooden Tool Used during the Production of PDO Provola dei Nebrodi Cheese

2021

The biofilms of the wooden tables used for the acidification of the curd were investigated for PDO Provola dei Nebrodi cheese, a traditional stretched cheese made in eastern Sicily (southern Italy) from raw cows’ milk. To this purpose the wooden tables of four dairy facilities were analysed for their microbiota by scanning electron microscopy (SEM) analysis and a combined culture-independent and -dependent microbiological approach. SEM inspection showed an almost continuous biofilm formation. MiSeq Illumina analysis identified 8 phyla, 16 classes, 25 orders, 47 families and 50 genera. Corynebacterium, Bifidobacterium and lactic acid bacteria (LAB) were detected in all samples. In particular…

Thymus vulgaris Essential Oil and Hydro-Alcoholic Solutions to Counteract Wooden Artwork Microbial Colonization

2021

Aromatic plants represent a source of natural products with medicinal properties, and are also utilized in the food and pharmaceutical industries. Recently, the need for eco-compatible and non-toxic products, safe for both the environment and human health, have been proposed for the sustainable conservation of historic–artistic artifacts. In this study, in order to counteract microbial colonization (Aspergillus sp., Streptomyces sp., Micrococcus sp.) on wooden artwork surfaces, Thymus vulgaris L. (Lamiaceae) essential oil (EO) and hydro-alcoholic (HA) solutions were applied in a polyphasic approach. The antimicrobial activities of EO and HA solutions were preliminarily assessed by agar disc…

Reactivity of cellulose during hydrothermal carbonization of lignocellulosic biomass

2020

Abstract Hydrothermal carbonization (HTC) of pure cellulose (CE) and birchwood (BW) samples was carried out at temperatures between 160 and 280 °C, 0.5 h residence time and biomass-to-water ratio 1:5, to investigate the reactivity of cellulose in lignocellulosic biomass. Thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) showed that the CE samples remained unaltered at temperatures up to 220 °C, but were significantly decomposed at 230 °C producing a thermal recalcitrant aromatic and high energy-dense material. FTIR showed that dehydration and aromatization reactions occurred at temperature equal or higher than 230 °C for the CE samples while a similar incre…

Combining in the melt physical and biological properties of poly(caprolactone) and chlorhexidine to obtain antimicrobial surgical monofilaments.

2012

Bacterial infections on a sutured wound represent a critical problem, and the preparation of suture threads possessing antimicrobial properties is valuable. In this work, poly(caprolactone) (PCL) monofilaments were compounded at the concentration of 1, 2 and 4 % (w/w), respectively, to the antiseptic chlorhexidine diacetate (CHX). The incorporation was carried out in the melt by a single-step methodology, i.e. “online” approach. Mechanical tests revealed that the incorporation of CHX does not significantly change tensile properties of PCL fibres as the thermal profile adopted to prepare the compounded fibres does not compromise the antibacterial activity of CHX. In fact, CHX confers to comp…

Contaminanti chimici e microbiologici nel tonno

2009

Fragments of β-thymosin from the sea urchin Paracentrotus lividus as potential antimicrobial peptides against staphylococcal biofilms.

2012

The immune mediators in echinoderms can be a potential source of novel antimicrobial peptides (AMPs) applied toward controlling pathogenic staphylococcal biofilms that are intrinsically resistant to conventional antibiotics. The peptide fraction5 kDa from the cytosol of coelomocytes of the sea urchin Paracentrotus lividus (5-CC) was tested against a group of Gram-positive and Gram-negative pathogen reference strains. The 5-CC of P. lividus was active against all planktonic-tested strains but also showed antibiofilm properties against staphylococcal strains. Additionally, we demonstrated the presence of three small peptides in the 5-CC belonging to segment 9-41 of a P. lividusβ-thymosin. The…

Microbial dynamics in durum wheat kernels during aging

2020

In the present work the microbial dynamics in wheat kernels were evaluated over time. The main aim of this research was to study the resistance of lactic acid bacteria (LAB) and yeasts associated to unprocessed cereals used for bread making during long term conservation. To this purpose four Triticum durum Desf. genotypes including two modern varieties (Claudio and Simeto) and two Sicilian wheat landraces (Russello and Timilia) were analysed by a combined culture-independent and -dependent microbiological approach after one, two or three years from cultivation and threshing. DNA based MiSeq Illumina technology was applied to reveal the entire bacterial composition of all semolina samples. T…