**4. Results and discussion**

Table 2 presents the development of the *L. strigosus*. The fructification happened three to five days after the primordia initiation (Table 2), with the development of vigorous mushrooms.


Table 2. Profile of the *Lentinus strigosus* mushroom cultivated in cajuí sawdust with soy bran as protein source during 100 days.

The high biological efficiency (BE) of the substrate formulated with cajuí sawdust, supplemented with soy bran demonstrates good productivity of the substrate (Table 3). The result (80%) is superior to other substrates used in cultivation of *P. ostreatus* mushroom formulated with sawdust of *Fagus orientalis* (Yildz et al., 2002), and with *Eucalyptus* sp. according to Marino et al. (2002) which presented BE equal to 8.6 to 64.3% and 11.4 to 43% in their respective studies. The good productivity of this substrate is the result of the quantity of material readily available and absorbed by fungus during the mycelial development process and the soy bran was a good source of protein.

Philippoussis *et al*. (2003) showed that the mycelial growth rate is related to the bioavailability of nitrogen and that the formulation of the substrate influences nutritional levels and porosity (availability of O2) and Gbolagade *et al*. (2006) stated that each fungus utilizes a specific C/N ratio. The soy bran provided a good source of protein for the fungus as we can see at the table 3 (20%). The results are very important for this edible mushroom, since they present low lipid content (2.5%) and a high fiber level (18%).

The use of alternative substrates, easily obtained at low cost for the cultivation of edible mushrooms have been investigated in many publications (Özçelik and Pekşen, 2007; Philippoussis *et al*., 2007; Royse and Sanchez, 2007). The supplementation of the substrates with a nitrogen source, mainly with cereal bran, has been adopted to achieve a C/N ratio good for the production of mushrooms.

Özçelik and Pekşen (2007), analyzing the application of hazelnut shells in the formulation of substrate for mushroom cultivation *Lentinula edodes*, reported that the biological efficiency of the substrate made with hazelnut shells only, was considered to be low (43.73%). However, when the proportion of hazelnut shells was reduced and combined with wheat straw (25:75) the biological efficiency was considered good (62.24%). The result however, is less than that reported in this study (Table 3).

Philippoussis et al. (2007) tested the productivity of agricultural residues (sawdust of oak, wheat straw and corncobs) in the cultivation of *Lentinula edodes* and found that corncobs and wheat straw presented higher rates of biological efficiency: 80.64% and 75.23% respectively, which were similar to those presented in this research. Alberto and Lechner (2007) however, obtained lower BE (61.93%), cultivating *Lentinus tigrinus* with Salix sawdust.

Royse and Sanchez (2007) tested three formulations for the cultivation of *L. edodes*, combining wheat straw and oak residues. They found that the substrate with higher proportions of wheat straw (in relation to oak residue), provided the best biological efficiency (98.9%) at the end of 4 harvests. These results are superior to the ones obtained in this work. However, 80% of Biological Efficiency presented by *L. strigosus* cultivated in cajuí sawdust supplemented with soy bran in the present study is considered high.


Table 3. Results of Productivity and Nutritional Composition of the edible mushroom *Lentinus strigosus* cultivated on cajuí wood waste, supplemented with soy bran.
