1,721,014 research outputs found
Simulazione e monitoraggio in microcosmo della degradazione di un composto tossico volatile ad opera di microrganismi fungini
No full textIl lavoro sperimentale ha avuto come scopo la definizione di una serie di metodiche per l'allestimento e per il monitoraggio di un microcosmo in beute Erlenmeyer, inoculato con microrganismi fungini, in presenza di suolo naturale inquinato artificialmente con naftalene. Dopo aver definito le modalità di allestimento e monitoraggio del microcosmo, ne è stata valutata la funzionalit
Valorisation Proposal of Brewery Spent Grain: Carotenoids and Protein Films Production
Full text linkThe preliminary Brewery Spent Grain (BSG) valorisation proposed is based on the production of cultural media for the growth of the carotenogenic yeast Rhodotorula mucilaginosa; the realisation of protein-rich films is also presented. First experiments, carried out with three BSGs, allowed to define the best extraction set-up, realizing water extraction in agitation (ratio BSG/water= 0.05, at 25 °C, for 2 hrs). Then, using the same water extraction conditions, BSG with the highest total solid content was applied to produce a concentrated syrup (BSG/water= 0.2). Yeast growth and carotenoid production were tested on solid media prepared with water extracts and syrup. Later on, to define the best cultural medium, extracts and syrup were applied in different set of liquid cultures, carried out in 96-well plates, maintained at 25 °C, in agitation. Syrup was utilized as it is or supplemented with inorganic and organic N sources, and the addition of these latter returned better results. Afterward, a scale-up carried out into Erlenmeyer flasks (500 mL) allowed to evidence the possibility of using the syrup as it is for the growth of R. mucilaginosa and carotenoids production. Finally, a high protein content syrup (BSG/water= 0.2), prepared in autoclave (at 121 °C, 2 atm, for 20 min), was evaluated for the production of films: best filming conditions were investigated and amorphous semi-transparent films were obtained
Mycotoxins: Are They Perceived as a Serious Threat for the Human Health?
No full textMycotoxins contamination and the associated risks are well known from the scientific community as it is possible to desume from the huge amount of the related scientific publications. Although the threat for human and animal health is really high and the worldwide diffusion of the contamination is for the most part uncontrollable, the public opinion is not really conscious of the problem and sometimes ignores it. In the present paper, a brief description of different aspects related to mycotoxins contamination is reported as regard toxicology and risks for the health, recent European and global regulations, and laboratory methods for mycotoxins determinatio
Fungal biodegradation of naphthalene: microcosms studies
No full textThe present work is aimed to ascertain naphthalene biodegradation capability of P. chrysosporium and T. harzianum in soil microcosms. Considering the high naphthalene volatility, a suitable soil microcosm was set-up and used. Several degradation tests were conducted with different C/N ratio media for the two fungi in order to enquire the best range of working conditions. The kinetic studies were conducted at a maximal naphthalene concentration of 600 mg kg1. During experimental time course naphthalene concentration, CO2 evolution as well as phytotoxicity tests were performed as monitoring parameters. The results shown in the current paper, put in evidence that T. harzianum, differently than in liquid culture, is not able to biodegrade naphthalene directly in soil microcosm, while P. chrysosporium in the same conditions biodegrades the PAH till about 600 mg kg1. As concern the founded kinetics for P. chrysosporium, a saturation shape in presence of N-limited medium (high C/N ratio) was evaluated while a growing form more than linear in no-N limited medium (normal C/N ratio) was determined
Vapor Phase Application of Thymus vulgaris Essential Oil to Control the Biodeteriogenic Fungus Alternaria alternata
Full text linkIn the present work, the antimicrobial efficacy of Thymus vulgaris essential oil (EO) was investigated on Alternaria alternata strain BNR; a paper biodeteriogen was used as a model for a contaminated library. The influence of EO volume and diffusion modality, treatment duration, and inoculum age was evaluated in the vapor phase. In Petri dish screening, the influence of different EO volumes (5, 7.5, and 10 μL) on the microbial growth lag phase was investigated, and the growth inhibition period was established. The most effective treatment (10 μL EO) was then scaled up in a glass airtight container of 2650 cm3; a cold diffusion method was applied in order to quickly reach the maximum concentration of active compounds in the vapor phase. These tests demonstrated that EO efficacy is affected by the inoculum age and the contact time, and that the treatment should be performed as early as is feasible. A mycostatic effect was confirmed to be proportional to the utilized EO volume and independent from the treatment method. The information obtained in the present work will be applied to the set-up of an EO treatment in a library characterized by different levels of air contamination
Il recupero delle pectine da bucce di fave di cacao
No full textLe bucce delle fave di cacao, uno scarto tipico della produzione del cioccolato, possono essere valorizzate come fonte per la produzione di pectine, additivi gelificanti di largo impiego. Nel presente lavoro vengono presentati i risultati relativi allo sviluppo e all'ottimizzazione, su scala di laboratorio, dell'estrazione delle pectine da questi scarti. Lo studio del processo è avvenuto sulla base di quello tradizionalmente utilizzato per le produzioni industriali. Dallo studio è emerso che la migliore resa è ottenuta con una estrazione effettuata a pH 2,5 a 95°C per 1 ora; le pectine così prodotte sono caratterizzate da un basso grado di metilesterificazione e di acetilazione. I buoni risultati ottenuti costituiscono la base per un ulteriore approfondimento volto a rendere competitivo il processo in termini di resa, economia e qualità del prodotto final
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