Microbial diversity in a bagasse-based compost prepared for the production of Agaricus brasiliensis

Abstract

Edible mushrooms are renowned for their nutritional and medicinal properties and are thus of considerable commercial importance. Mushroom production depends on the chemical composition of the basic substrates and additional supplements employed in the compost as well as on the method of composting.In order to minimise the cost of mushroom production, considerable interest has been shown in the use of agro-industrial residues in the preparation of alternative compost mixtures. However, the interaction of the natural microbiota present in agricultural residues during the composting process greatly influences the subsequent colonisation by the mushroom. The aim of the present study was to isolate and identify the microbiota present in a sugar cane bagasse and coast-cross straw compost prepared for the production of Agaricus brasilienses. Composting lasted for 14 days, during which time the substrates and additives were mixed every 2 days, and this was followed by a two-step steam pasteurisation (55 -65°C; 15 h each step).Bacteria, (mainly Bacillus and Paenibacillus spp. and members of the Enterobacteriaceae) were the predominant micro-organisms present throughout the composting process with an average population density of 3 x 10 8 CFU/g. Actinomycetes, and especially members of the genus Streptomyces, were well represented with a population density of 2 -3 x 10 8 CFU/g. The filamentous fungi, however, exhibited much lower population densities and were less diverse than the other micro-organisms, althoughAspergillus fumigatus was present during the whole composting process and after pasteurisation.

Assessment of bacterial diversity during composting of agricultural byproducts

“…Silva et al . [42] also found Serratia sp. in bagasse and coast-cross straw during the first stage of composting.…”

Study on the Cultivation of <i>Agaricus blazei</i> (Almond Mushroom) Grown on Compost Mixed with Selected Agro-Residues

“…They have attracted the attention of the biotechnological industries as food supplements or materials for developing medicines [2]. The mushroom species of Agaricus blazei (Cogumelo do sol), Agaricus bisporus (Champignon), Pleurotus sajor-caju (Oyster mushroom) and Lentinula edodes (Shiitake) are of important economic value on account of their exquisite flavor and proven medicinal properties [3]. The A. blazei is naturally found on organic litter which has already been occupied by the first stage decomposers capable of digesting complex lignocellulosic components [4].…”

Screening of Antimicrobial and Antioxidant Secondary Metabolites from Endophytic Fungi Isolated from Wheat (Triticum Durum)

“…The isolates of actinomycetes were characterized up to genus level according to traditional morphological criteria. The characteristics of colonies on the plate, the distinctive reverse colony color, morphology of substrate and aerial hyphae, morphology and mass color of spores as well as diffusible pigment produced were all taken into consideration (Holt et al 1994;Silva et al 2009;Verma et al 2009). …”