31 research outputs found
ASPERGILLI CONTAMINANTI DERRATE AD USO UMANO E ZOOTECNICO: attività enzimatica, tecniche diagnostiche innovative e possibili strategie di difesa biologica.
Fungal contaminants in Sicilian livestock feeds and first studies on the enzymatic activity of Aspergillus isolates
The purposes of this study were 1) to determine the total fungal contamination in Sicilian raw materials and livestock, 2) to evaluate the occurrence of Aspergillus spp., Penicillium spp. and Fusarium spp., 3) to identify fungi belonging to the genus Aspergillus and 4) to determine their ability to produce cellulolytic enzymes. Fourteen feed samples were collected in a feed mill near to Palermo (Sicily, Italy). Analysis of the total mycobiota was performed on Sabourad Dextros Agar (SAB) and Potato Dextrose Agar (PDA) and total fungal counts were expressed as CFU/g. Aspergillus spp. isolates were selected on the basis of the frequency of isolation and identifed using micro and macro-morphological characteristics and ITS sequence analysis. The ability of the Aspergillus isolates to produce cellulolytic enzymes was tested qualitatively by in vitro assay at two temperature, 25 and 30 °C, and in static and shaking condition. Total fungal population ranged from 1.11x106 to 1.31x108 and from 1.11x103 to 1.58x106 CFU/g on PDA and SAB, respectively. All feed samples showed the recurrent presence of colonies belonging mostly to the ubiquitous genera Aspergillus, Fusarium and Penicillium. Eight isolates of Aspergillus spp. were obtained and identifed as A. amstelodami, A. awamori, A. flavus, A. niger, A. oryzae and A. tubingensis. Between them, A. awamori, A. niger and A. tubingensis showed the highest enzymatic activity. The presence of potential mycotoxigenic isolates of Aspergillus spp. in the analysed feeds represents a risk for animal health; moreover their ability to produce cellulolytic enzymes can seriously affect feed quality
Primi studi sull'interazione tra stato di micorrizazione e danni da incendio in una pineta siciliana
Nell’ambito di uno studio sulle simbiosi micorriziche delle conifere in ambienti siciliani, è stata avviata un’indagine preliminare sulla interazione tra danni da incendio e stato di micorrizazione in un rimboschimento artificiale di Pinus halepensis Mill. In particolare, nel bosco di Casaboli (Monreale, PA) estesamente interessato da incendi dolosi nell’estate 2017, sono state delimitate tre aree contigue di circa 700 m2, comprendenti una ventina di piante coetanee (30-40 anni) e con differente entità di danno: 1) vegetazione apparentemente sana (S); danni di media entità (M); danni ingenti (I). In ogni area, dopo aver condotto opportuni rilievi dendrometrici, sono stati individuati 5 punti per il prelievo di carote di suolo a due profondità (5-15; 20-30 cm); i campionamenti sono stati ripetuti tre volte nel biennio 2018-19 (giugno e novembre 2018, maggio 2019) e saranno completati a novembre 2019. I frammenti radicali di P. halepensis, recuperati sotto un leggero flusso d’acqua corrente, sono stati osservati allo stereo microscopio, valutando l’Indice di Micorrizazione (IM = n° totale di apici micorrizici/cm di radice) e rilevando, sul numero totale di apici micorrizici, la percentuale di quelli attivi e non (necrotici). Sebbene l’indagine sia ancora in corso, i primi risultati sembrerebbero evidenziare valori di IM maggiori nell’area S, decrescenti in funzione del livello di deperimento. Nel contempo, nel profilo di suolo compreso tra 20 e 30 cm sono stati rilevati i maggiori livelli di micorrizazione, che rimane sensibile anche nelle aree più danneggiate. Ulteriori dati acquisiti nel corso dell’attività di ricerca potranno fornire utili indicazioni per la definizione degli effetti di tale fattore di disturbo nell’ecosistema oggetto di studio
Fungal Contaminants and Mycotoxins in Nuts
Contamination by fungi and mycotoxins in nuts has achieved much attention in recent years. In fact, the fungal metabolites produced by the species of Aspergillus, Penicillium (aflatoxins and ochratoxins), Fusarium (trichothecenes, zearalenones and fumonisins) and Alternaria (alternariotoxins) with toxic and/or carcinogenic effects are considered a threat to human and animal health. In this chapter we will discuss the main fungal taxa and related mycotoxins most frequently associated with these materials. In this regard, the first results on the level of contamination by fungi and mycotoxins in samples of almonds and pistachios of different origins will be reported. The main strategies to reduce the risk of contamination will also be recommended
Ligninolytic potential of Curvularia kusanoi L7 laccases for animal production
The present research was conducted with the objective of evaluating the ligninolytic potential of Curvularia kusanoi L7 laccases in improving the nutritional quality of fibrous substrates for animal feed. Laccase production was obtained from C. kusanoi L7 under native conditions by solid submerged fermentation of wheat bran and by biological interactions with Trichoderma viride M5-2 and Trichoderma pleuroticola. The enzymes were
purified from the culture broths by triphasic partition. The degradative potential of native and induced laccases where evaluated by determining foliar lignololytic capacity, raw wheat (Triticum aestivum) straw delignification and the effect of enzyme pretreatment on fibrous fractionation and in vitro digestibility of sugarcane bagasse. Laccases, both native and induced, presented high foliar degradation and delignification of raw wheat straw.
Regarding to the improvement of nutritional quality of sugarcane bagasse, all the enzyme pretreatments managed to decrease the fiber content and increase in vitro digestibility. Compared to untreated bagasse, native laccase pretreatment obtained the highest digestibility values (P<0.05) for dry matter (54.71 %), organic matter (63.14 %), acid detergent fiber (63.59 %) and cellulose (65.46%). It is concluded that C. kusanoi L7 laccases
can be used as a novel tool in improving the nutritional quality of fibrous sources for animal feed.La presente investigación se condujo con el objetivo de evaluar la capacidad ligninolÃtica de las enzimas lacasas del hongo Curvularia kusanoi L7 en el mejoramiento de la calidad nutritiva de fuentes fibrosas para su empleo en la alimentación animal. La producción de lacasas se obtuvo mediante fermentación sólido sumergida del salvado
de trigo, en condiciones nativas y con inducción por interacciones biológicas con Trichoderma viride M5-2 y Trichoderma pleuroticola y se purificaron mediante partición trifásica. La capacidad degradativa
de las enzimas nativas e inducidas se evaluó mediante la determinación de su capacidad lignolÃtica foliar, deslignificación de la paja cruda de Triticum aestivum (trigo) y determinación del efecto del pretratamiento
enzimático en el fraccionamiento fibroso y la digestibilidad in vitro del bagazo de Saccharum officinarum (caña de azúcar). Las lacasas, tanto nativas como inducidas, presentaron resultados similares de degradación foliar y deslignificación de la paja de trigo cruda. En cuanto a la calidad nutricional del bagazo de caña de azúcar, los pretratamientos enzimáticos logaron disminuir los componentes fibrosos, e incrementar su digestibilidad in vitro. Respecto al bagazo sin tratar, el pretratamiento con lacasa nativa presentó los mayores valores (P<0.05) de digestibilidad de la materia seca, (54.71 %) de la materia orgánica (63.14 %) de la fibra de detergente ácido (63.59 %) y de la celulosa (65.46%). Se concluye que el potencial ligninolÃtico de las lacasas de C. kusanoi L7 y su capacidad para mejorar la calidad nutritiva y la digestibilidad in vitro del bagazo de caña de azúcar, encaminan su evaluación in vivo en la alimentación de especies monogástricas y rumiantes
Cultivable fungal endophytes in roots, rhizomes and leaves of Posidonia oceanica (L.) Delile along the Coast of Sicily, Italy
The presence of endophytic fungi in the roots, rhizomes, and leaves of Posidonia oceanica was evaluated in different localities of the Sicilian coast. Samples of roots, rhizomes, and leaves were
submitted to isolation techniques, and the obtained fungal colonies were identified by morphological and molecular (rRNA sequencing) analysis. Fungal endophytes occurred mainly in roots and
occasionally in rhizomes and leaves. Lulwoana sp. was the most frequent of the isolated taxa, suggesting a strong interaction with the host. In addition, eight other fungal taxa were isolated.
In particular, fungi of the genus Ochroconis and family Xylariaceae were identified as endophytes in healthy plants at all sampling stations, whereas Penicillium glabrum was isolated at only one
sampling station. Thus, several organs, especially roots of Posidonia oceanica, harbor endophytic fungi, potentially involved in supporting the living host as ascertained for terrestrial plants
Indagini preliminari sull’attività di degradazione di basidiomiceti cariogeni su legno di castagno
Recentemente, presso il Dip. SAAF e in collaborazione con l‘Instituto di Ciencia Animal (ICA) di Cuba, sono state avviati studi rivolti alla valutazione dell’attività celluloso-ligninolitica da parte microrganismi isolati da diverse matrici naturali. Alcuni primi risultati hanno consentito di rilevare la produzione di enzimi litici (cellulasi, laccasi, ecc.) in diversi funghi in collezione. Nell’ambito di questa ricerca, 5 colonie fungine appartenenti a quattro differenti specie di basidiomiceti cariogeni (Armillaria mellea (Val) P. Kumm, Fistulina hepatica (Shaeffer) Withering, due Ganoderma resinaceum Boud e Laetiporus sulphureus (Bull.) Murrill) sono state saggiate su campioni di legno di castagno (rondelle e segatura) provenienti da due siti siciliani (Ficuzza, Palermo e Nebrodi, Messina) e uno toscano (Sammommè, Pistoia). In particolare sono state valutate: 1) la velocità di colonizzazione di ciascun isolato fungino su rondelle delle matrici legnose dei tre siti; 2) la produzione di CO2 conseguente all’attività litica sulle matrici; 3) la risposta quali-quantitativa di ciascuna colonia fungina alla siringaldazina, un azo-composto organico reattivo alle laccasi e perossidasi, enzimi chiave nella degradazione della lignina. I risultati preliminari indicano sia una differente attività litica, a parità di matrice, dei microrganismi studiati, sia una diversa risposta delle matrici, in relazione alla provenienza, a parità di specie fungina. Ulteriori indagini saranno rivolte allo studio del corredo enzimatico dei funghi saggiati e alla caratterizzazione chimico-fisica delle differenti accessioni di castagno, allo scopo di individuare i maggiori determinanti nel processo degradativo del legno
Inhibition of ERK1/2 signaling prevents bone marrow fibrosis by reducing osteopontin plasma levels in a myelofibrosis mouse model
Clonal myeloproliferation and development of bone marrow (BM) fibrosis are the major pathogenetic events in myelofibrosis (MF). The identification of novel antifibrotic strategies is of utmost importance since the effectiveness of current therapies in reverting BM fibrosis is debated. We previously demonstrated that osteopontin (OPN) has a profibrotic role in MF by promoting mesenchymal stromal cells proliferation and collagen production. Moreover, increased plasma OPN correlated with higher BM fibrosis grade and inferior overall survival in MF patients. To understand whether OPN is a druggable target in MF, we assessed putative inhibitors of OPN expression in vitro and identified ERK1/2 as a major regulator of OPN production. Increased OPN plasma levels were associated with BM fibrosis development in the Romiplostim-induced MF mouse model. Moreover, ERK1/2 inhibition led to a remarkable reduction of OPN production and BM fibrosis in Romiplostim-treated mice. Strikingly, the antifibrotic effect of ERK1/2 inhibition can be mainly ascribed to the reduced OPN production since it could be recapitulated through the administration of anti-OPN neutralizing antibody. Our results demonstrate that OPN is a novel druggable target in MF and pave the way to antifibrotic therapies based on the inhibition of ERK1/2-driven OPN production or the neutralization of OPN activity
Pistachio fruits rust caused by Tuberculina persicina (Ditmar) Sacc., anamorph of Helicobasidium purpureum (Tul.) Pat.
In the study, we found rust in pistachio fruits and verified that it was caused by Tuberculina persicina, anamorph of Helicobasidium purpureum, through isolation and culture, microscopic observation, molecular identification and pathogenicity tests of Koch’s postulates. To our knowledge, this is the first report of rust fruit in pistachio caused by Tuberculina persicina