Attacks of Kalotermes flavicollis in Palermo and associated Aspergillus species

Tra le termiti della famiglia Kalotermitidae, una delle più primitive tra gli Isotteri e tipica del legno umido, la specie Kalotermes flavicollis Fabr. si distingue per essere nota come ‘termite del legno secco dal collo giallo’. Recentemente, in edifici pubblici e privati e in due chiese di Palermo sono stati rinvenuti diversi nidi di K. flavicollis, associati ad attacchi sia di parti strutturali, che di manufatti, alcuni dei quali di rilevante pregio e valore artistico. Il loro comportamento lucifago ha reso difficile la precoce individuazione delle infestazioni, sottovalutandone il rischio, fino alla manifestazione dei danni. Le colonie identificate erano costituita da circa 400-500 individui, mentre i voli nuziali di maschi e femmine sono stati registrati nei mesi di ottobre e novembre degli anni 2019 – 2021. Durante il monitoraggio sono stati rilevati diversi individui morti e con evidenti efflorescenze fungine. Si è ritenuto opportuno, quindi, effettuare uno studio rivolto all’isolamento e all’identificazione di tali microrganismi. Allo scopo, dai nidi con individui infetti sono stati prelevati alcuni campioni di materiale ligneo e di insetti da sottoporre alle opportune analisi di laboratorio. Le prime osservazioni al microscopio stereoscopico hanno evidenziato la presenza di teste conidiche di Aspergillus, di colore giallo-ocraceo, portate da lunghi conidiofori emergenti dal corpo degli insetti. Sono stati condotti, quindi, isolamenti diretti e indiretti (diluizioni seriali) su substrato nutritivo agarizzato PDA. Le colonie fungine accresciute sono state allevate in purezza e osservate al microscopio ottico per la loro identificazione morfologica su base dei caratteri macro- e microscopici. Le colonie ricorrenti sono state sottoposte ad estrazione di DNA e amplificazione dei geni ITS e β-tubulina. Le analisi morfologiche e molecolari hanno consentito di identificare Aspergillus nomius, A. subramanianii e A. tamarii. In letteratura, A. nomius è stato segnalato, su termiti della specie Coptotermes formosanus, sia come saprofita che come parassita facoltativo, su insetti sottoposti a qualche forma di stress, mentre A. tamarii è stato identificato in associazione a quelle della specie Psammotermes hypostoma. In questo studio A. subramanianii, viene segnalato per la prima volta in associazione a termiti. Ulteriori indagini potranno fornire utili indicazioni sull’eventuale ruolo ecologico che questi funghi rivestono, sia singolarmente che in consociazione, sulla vitalità delle colonie di K. flavicollis, anche nell’ottica della messa a punto di mirate strategie di biocontrollo

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

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

Pleurotus nebrodensis (Basidiomycota), a rare endemic mushroom of Sicily: current and future issues

This paper deals with the basidiomycete Pleurotus nebrodensis, one of the rare examples of endemic fungi in Italy and Europe. After clarifying the taxonomy of this taxon, including a comparison with a species from China misidentified as “Pleurotus nebrodensis”, we describe the characteristics of its natural habitat, and provide a new morphological description and information on its pilot-scale cultivation, current conservation status according to IUCN criteria and conservation strategies. New ITS region sequences were deposited in GenBank. Furthermore, the antibacterial and anti-cancer properties of P. nebrodensis are mentioned, making it a potential medicinal mushroom. Finally, a critical analysis, on a phylogenetic basis, of the Italian production of substrates inoculated with “P. nebrodensis” strains is also included

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 ligninolítica 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 lignolítica 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 ligninolítico 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