Morphological and molecular identification of four Brazilian commercial isolates of Pleurotus spp. and cultivation on corncob

The species of Pleurotus have great commercial importance and adaptability for growth and fructification within a wide variety of agro-industrial lignocellulosic wastes. In this study, two substrates prepared from ground corncobs supplemented with rice bran and charcoal were tested for mycelium growth kinetics in test tubes and for the cultivation of four Pleurotus commercial isolates in polypropylene bags. The identification of the isolates was based on the morphology of the basidiomata obtained and on sequencing of the LSU rDNA gene. Three isolates were identified as P. ostreatus, and one was identified as P. djamor. All isolates had better in-depth mycelium development in the charcoal-supplemented substrate. In the cultivation experiment, the isolates reacted differently to the two substrates. One isolate showed particularly high growth on the substrate containing charcoal.

Espécies de Pleurotus têm grande importância comercial e adaptabilidade para crescimento e frutificação em uma ampla variedade de resíduos agro-industriais lignocelulósicos. Neste trabalho foram testados dois substratos à base de sabugo de milho triturado, suplementados com farelo de arroz e carvão vegetal, para avaliação da cinética de crescimento micelial em tubos de ensaio e produção em sacos de polipropileno, utilizando quatro isolados comerciais. O estudo taxonômico foi realizado com a análise da morfologia dos basidiomas obtidos em cultivo e pelo seqüenciamento do gene nLSU do DNAr, para certificar a identificação taxonômica. Os isolados tiveram melhor desenvolvimento micelial em profundidade no substrato suplementado com carvão vegetal. Em relação à produção, os isolados reagiram de formas distintas em função dos substratos, sendo significativamente melhor o substrato contendo carvão. Três isolados foram identificados como P. ostreatus e o outro foi identificado como P. djamor.

Agaricales Fungi from atlantic rain forest fragments in Minas Gerais, Brazil

Two Atlantic Rain Forest fragments in Minas Gerais state were studied to access their Agaricales fungal richness. A total of 187 specimens were collected and 109 species, 39 genera, and eight families were identified. Thirty-three species were cited for the first time in Brazil.

Screening of Brazilian basidiomycetes for antimicrobial activity

A total of 103 isolates of basidiomycetes, representing 84 species from different Brazilian ecosystems, were evaluated for their antifungal and antibacterial activity in a panel of pathogenic and non-pathogenic microorganisms. Tissue plugs of the fruiting bodies were cultivated in liquid media and the whole culture extracted with ethyl acetate. Crude extracts from Agaricus cf. nigrecentulus, Agrocybe perfecta, Climacodon pulcherrimus, Gloeoporus thelephoroides, Hexagonia hydnoides, Irpex lacteus, Leucoagaricus cf. cinereus, Marasmius cf. bellus, Marasmius sp., Nothopanus hygrophanus, Oudemansiella canarii, Pycnoporus sanguineus, Phellinus sp., and Tyromyces duracinus presented significant activity against one or more of the target microorganisms. Eight isolates were active only against bacteria while three inhibited exclusively the growth of fungi. Two extracts presented wide antimicrobial spectrum and were active against both fungi and bacteria. Differences in the bioactivity of extracts obtained from isolates from the same species were observed.

Cultivation of the Edible mushroom Oudemansiella Canarii (Jungh.) HÖhn. in Lignocellulosic substrates

The edible mushroom Oudemansiella canarii (Jungh.) Höhn is common in the Brazilian territory, being found in different biomas, where they colonize several plant species. In this study, the O. canarii cultivation was evaluated in polypropilene bags containing sugar-cane bagasse (200 g) or eucalyptus sawdust (200 g) supplemented with wheat bran (50 g). The composts were sterilized at 121§C for 1 hour, after cooling they were inoculated with 3 g of spawn and then remained incubated at 25§C until the basidiomata primordia formation. The mushrooms, harvested after the pilei opening, presented varied sizes reaching 9 cm of diameter and 10 cm of height. The fresh mushrooms presented mild taste and soft consistency. When kept at 4§C, they maintained good appearance and good consistency for 7 days. In a period of 60 days, the largest basidiomata production was obtained in the compost with sugar-cane bagasse, showing greater productivity (4.47per cent ñ 1.34), biological efficiency (55.66per cent ñ 20.41) and compost consumption (38.78per cent ñ 4.59) averages. Wilcoxon's non-parametric statistical analysis used to compare the biomass production in the two composts, showed significant differences at 5 per cent significance level.