Evaluation of Ten Wild Nigerian Mushrooms for Amylase and Cellulase Activities

Amylases and cellulases are important enzymes that can be utilized for various biological activities. Ten different wild Nigerian mushrooms (Agaricus blazei, Agaricus sp., Corilopsis occidentalis, Coriolus versicolor, Termitomyces clypeatus, Termitomyces globulus, Pleurotus tuber-regium, Podoscypha bolleana, Pogonomyces hydnoides, and Nothopanus hygrophanus) were assayed for production of these secondary metabolites. The results revealed that most of the tested wild fungi demonstrated very good amylase and cellulase activities. With the incorporation of carboxymethyl-cellulose (a carbon source) into the culture medium, Agaricus blazei had the highest amylolytic activity of 0.60 unit/mL (at 25degrees C, pH 6.8). This was followed in order by P. tuber-regium and Agaricus sp. with 0.42 and 0.39 unit/mL, respectively (p < or = 0.05). Maltose and sucrose supplementation into the submerged liquid medium made N. hygrophanus and P. hydnoides to exhibit very low amylase activities of 0.09 and 0.11 unit/mL, respectively. Introducing peptone (an organic nitrogen source) into the basal medium enhanced the ability of C. versicolor to produce a cellulase value of 0.74 unit/mL. Other organic nitrogen sources that supported good cellulase activities were yeast extract and urea. Sodium nitrate (inorganic nitrogen source) generally inhibited cellulase production in all mushrooms. The best carbon source was carboxymethyl-cellulose, which promoted very high cellulase activity of 0.67 unit/mL in C. versicolor, which was followed in order by P. tuber-regium, T. chypeatus, and C. occidentalis (p < or = 0.05). Sucrose was the poorest carbon compound, supporting the lowest values of 0.01, 0.01, and 0.14 unit/mL in P. hydnoides, A. blazei, and Agaricus sp., respectively.

Effect of Spent Mushroom Compost of Pleurotus pulmonarius on Growth Performance of Four Nigerian Vegetables

Spent mushroom compost (SMC) of Pleurotus pulmonarius (an edible fungus) was used as soil conditioner for the improvement of growth of four common Nigerian vegetables (Abelmoschus esculentus, Lycopersicum esculentum, Capsicum annum and Capsicum chinense). The results of these investigations showed that the vegetables responded well to the SMC treatment. Each of them attained its best growth and gave the highest number of flowers and fruits when planted on 6 kg of depleted garden soil supplemented with 600 g of SMC. The control experiment that has the seedlings of the vegetables planted on 6 kg of depleted garden soil only, without the application of SMC, showed stunted and poor growth, with few or no flower and fruit production. A. esculentus was the best utilizer of iron utilizing 118.0 mg/kg in the SMC used. Similarly; this vegetable utilized 1.48 mg/kg of nitrogen in the SMC. The highest height in each vegetable was attained with 6 kg of depleted garden soil supplemented with 600 g of SMC. At 9 wk, A. esculentus has the mean height of 85.0 cm while these values significantly increased to 100.00 cm at 14 wk (p < or = 0.05). At 9 wk, L. esculentum has the highest mean height of 65.00 cm which increased to 71.00 cm after 14 wk. It was also observed that A. esculentus has the highest mean number of fruits (9.00), followed in order by C. chinense (8.00) and L. esculentus (7.00) (p < or = 0.05) while, C. annum produced the least mean number of fruits (5.00). No fruits production was seen in the control experiments. The results of these findings were discussed in relation to the usage of SMC as possible organic fertilizer for the improvement of growth of vegetables in Nigeria.