Cultivo micelial in vitro e elaboração de “semente-inóculo” de Lentinus strigosus, um cogumelo comestível isolado na Amazônia

Abstract

The Amazonas State presents favorable scenery for the development of thefungiculture, because gathers the native diversity of species of edible mushrooms and abundantly substrates lignocellulosics. However, the protocols of cultivation are usually described for species of temperate climate habitat, being necessary the development of protocols for species of tropical climate. The specie Lentinus strigosus (Schwein.) Fr. (=Panus rudis Fr.) has a wide world distribution presenting several ecotypes. The edibility of this specie has been reported in ethnomycology studies of indigenous groups in the Amazon. However, your potential production in commercial scale has still been a little explored. In this study, reported the optimum conditions in vitro of mycelial growth of L. strigosus. The isolated presented characteristics of thermophile filamentous mushroom, with growth in temperatures from 25 to 45°C, being the optimum growth temperature, 35°C. This temperature is an important advantage for the development of the fungiculture in the tropics, since it is a common temperature for the region. In relation to the substrates for spawn preparation, in a first phase, the mycelial growth of L. strigosus was evaluated in based on sawdust formulations of 11 forestry regional species: Hymenolobium petraeum Ducke (Angelim pedra), Hura crepitans L. (Assacu), Bertholletia excelsa H.B.K. (Castanheira), Cedrela odorata L. (Cedro), Bombacopsis quinata (Jacq.) Dugand. (Cedro doce), Hymenaea courbaril L. (Jatobá), Ocotea cymbarum Kunth (Louro canela), Simarouba amara Aubl. (Marupá), Astronium lecointei Ducke (Muiracatiara), Aniba rosaeodora Ducke (Pau rosa) and Caryocar sp. (Piquiarana) and Eucalyptus sp. in comparison, main substratum used in the fungiculture of the South and Southeast of Brazil and Quercus acutissima Carr., very used in Asia. The sawdusts were supplemented with 20% (w/w) of rice bran. The substrates formulated with sawdust of B. quinata and S. amara they promoted higher mycelial growth (p<0.05). In the second phase, was evaluated the mycelial growth in sawdust of S. amara supplemented with seven different nitrogen sources (20% w/w): rice bran, soy extract, beer yeast, passion fruit shell flour, soy fiber, wheat fiber and wheat germ. As control was utilized pure sawdust. All the supplements favored in different levels the mycelial growth of L. strigosus. Bags and flasks of polypropylene were tested for spawn production and utilizing sawdust of S. amara, H. petraeum and A. lecointei supplemented with rice bran, after 25 days of inoculation the substrates were totally colonized by L. strigosus in all the packings tested. For choice of the packing other criteria should be considered aspects as costs of the packings; time of colonization; transport viability and feasibility of mycelial inoculation on the substratum. By these results, the spawn of L. strigosus was elaborated with success, being used sawdust of S. amara supplemented with 20% (w/w) of rice bran, at 35°C during 25 days, in the dark, in three packings with different characteristics.