RESUMEN
Solid-state fermentation of cereals with edible fungi is a promising strategy for producing functional flours. Hypothetically, the nutritional and functional properties of these flours could be modulated by manipulating substrate composition, fungal species, and incubation conditions. This article reports the variation over time in nutritional, polyphenol, and triterpene contents, as well as the antioxidant activity of rice and wheat fermented with Ganoderma sessile and Pleurotus ostreatus. Solid-state fermentation significantly improved the antioxidant power of the substrates which seemed to be highly correlated with the increase of the phenolic compounds. This increase peaked in the second to third week and decreased after this point. Triterpene content also increased, especially in substrates fermented with G. sessile. Substrates fermented with G. sessile showed higher values than those fermented with P. ostreatus in all compounds, which could be a result of a higher growth rate. Fermented wheat showed higher values than fermented rice in all measured compounds except reducing sugars which can be related to a slower progress in the fermentation due to the more complex structure of the wheat grain. Our results reinforce the importance of substrate and strain selection for product modulation to meet the industry's growing needs.
Asunto(s)
Antioxidantes , Grano Comestible , Fermentación , Ganoderma , Valor Nutritivo , Oryza , Pleurotus , Triticum , Pleurotus/metabolismo , Pleurotus/crecimiento & desarrollo , Pleurotus/química , Antioxidantes/metabolismo , Antioxidantes/análisis , Ganoderma/metabolismo , Ganoderma/química , Ganoderma/crecimiento & desarrollo , Oryza/química , Oryza/metabolismo , Grano Comestible/química , Grano Comestible/metabolismo , Triticum/química , Triticum/metabolismo , Polifenoles/metabolismo , Polifenoles/análisis , Polifenoles/química , Triterpenos/metabolismoRESUMEN
Phytophthora austrocedrae is a new species isolated from necrotic lesions of stem and roots of Austrocedrus chilensis. It is a homothallic species characterized by semipapillate sporangia, oogonia with amphigynous antheridia, and very slow growth (1-2 mm d(-1) on V-8 agar at 17.5 degrees C optimum temperature). Phylogenetic analysis of ITS rDNA sequence indicates that its closest relative is Phytophthora syringae, another species frequently isolated from soil and streams in A. chilensis forests.
Asunto(s)
Phytophthora/clasificación , Argentina , ADN de Hongos/genética , ADN Espaciador Ribosómico/genética , Filogenia , Phytophthora/genética , Phytophthora/aislamiento & purificación , Corteza de la Planta/microbiología , Enfermedades de las Plantas/microbiología , Raíces de Plantas/microbiología , Especificidad de la EspecieRESUMEN
The parenthesome structure of seven corticioid species, traditionally referred to the family Corticiaceae (Basidiomycota), were studied in order to better understand their taxonomic position: Phanerochaete velutina, Phlebia radiata, P. rufa, Rhizochaete americana (syn. Ceraceomyces americana), R. brunnea, R. filamentosa (syn. Phanerochaete filamentosa) and R. radicata (syn. Phanerochaete radicata). All possessed the perforate type of parenthesome that is commonly encountered in homobasidiomycetes. This feature excludes the above taxa from both the hymenochaetoid and the cantharelloid clades which are the only groups that have imperforate parenthesomes in the homobasidiomycetes.
Asunto(s)
Basidiomycota/clasificación , Basidiomycota/ultraestructura , Pared Celular/ultraestructura , Uniones Intercelulares/ultraestructuraRESUMEN
A survey of Phytophthora spp. in declining and healthy Austrocedrus chilensis forest was conducted to obtain an overview of the species that inhabit these forests. Seventeen declining and three healthy stands plus 11 associated streams were surveyed. Five Phytophthora species were recovered. P. syringae was the most common species isolated from soil and/or streams at nine declining sites and one healthy site. P. gonapodyides was isolated from streams only, at five declining sites. P. cambivora was isolated from soil and the undescribed taxa 'P. taxon Pgchlamydo' and 22 'P taxon Raspberry' were isolated from streams at one declining site each. The species were identified by ITS rDNA sequences and morphological features. Brief descriptions of each species and a discussion of their possible relationship with "mal del ciprés" are presented.