1,720,973 research outputs found
Pistachio fruits rust caused by Tuberculina persicina (Ditmar) Sacc., anamorph of Helicobasidium purpureum (Tul.) Pat.
No full textIn 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
Muffe e micotossine nelle derrate alimentari: danni, metodi di controllo e norme in vigore
No full textSecondo la FAO il 25% delle colture e il 70% dei mangimi nel mondo risulta contaminato da tossine prodotte da patogeni con enormi danni economic
Attacks of Kalotermes flavicollis in Palermo and associated Aspergillus species
Full text linkTra 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
Conservation Strategies of the Culinary-Medicinal Mushroom Pleurotus nebrodensis (Basidiomycota, Fungi)
Full text linkPleurotus nebrodensis (Inzenga) Quél. is an edible mushroom appreciated by consumers for its organoleptic characters. It was first described by the mycologist Giuseppe Inzenga as “the most delicious mushroom growing in Sicily”. This taxon, originally described as Agaricus nebrodensis Inzenga, has undergone several changes in the synomy and is recognized as a variety or subspecies within the Pleurotus eryngii (DC.) Quél. species complex. Recent studies demonstrated that P. nebrodensis is
distinct from other taxa related to the P. eryngii complex. The distribution of P. nebrodensis in Europe is limited. The mushroom grows only in Madonie Park (Sicily, Italy) and in Greece, associated with plants of Prangos ferulacea (Lindl.). Several studies demonstrated that the presence of P. nebrodensis in native territories has progressively decreased over the years. Research conducted in Sicily (southern Italy) during the fructification period (April–June 2009) confirmed this negative trend. The decision
to include P. nebrodensis as an endangered (EN) species on the IUCN Red List of Threatened Species was taken to safeguard the existence of this important taxon. Legal action is needed to stop the overexploitation and collection of unripe basidiomata of P. nebrodensis in the wild. Ex situ cultivation to increase wild production was experimented and preservation of mycelium in the Mycotheca of the Department of Agricultural, Food, and Forest Science (SAAF) of the University of Palermo was
carried out. The in situ conservation strategy can be implemented only if the wild collection is properly managed (picking of ripe mushrooms forbidden in zone A of Madonie Park and collection of unripe mushrooms forbidden in other areas)
Fungal contaminants and mycotoxins in nuts
Full text linkContamination 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
Full text linkThe 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
Cellulolytic activity in Aspergillus spp. contaminating livestock feeds and raw materials
No full textThe contamination by Aspergillus spp. have become a global concern in food and feedstuffs and can lead to a reduction in yield and quality of agricultural products with significant economic losses. Most species of Aspergillus produce cellulose-degrading enzymes and some of them also have mycotoxigenic activity. This study aimed i) to evaluate the Aspergillus contamination in feeds (16) and row materials (32) collected in Sicily; ii) to isolate and identify fungi belonging to the genus Aspergillus and iii) to analyze their ability to produce cellulolytic enzymes. Aspergillus spp. contamination was evaluated on PDA using serial ten-fold dilution and spread plate technique (Mirabile et al., 2019) and ranged from 50 to 9x106 CFU/g and from 45 to 3,3x107 in feeds and raw materials, respectively. The most recurrent colonies were identified by morphological features, ITS and β-tubulin sequence analysis as A. niger, A. tubingensis, A. brasiliensis, A. fumigatus and A. flavus.
Qualitative production of cellulolytic enzymes performed according to Mandels et al. (1976) and time course of endo and exo-β-1,4 glucanase activity (UI/ml) determined in solid submerged fermentation (Ghose, 1987), revealed a variability between Aspergillus species and was strain-dependent. A. tubingensis SAAF14, A. flavus MUCL18903 and A. brasiliensis MUCL20039 exhibited the highest CMCase and FPase activity of 2.16, 2.37 and 0.99 UI/ml and 0.65, 0.92, and 0.42 UI/ml, respectively. The presence of these Aspergillus isolates with high cellulolytic activity could represent a potential risk for the quality of the contaminated food
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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