ABSTRACT

Cultivation of mushrooms using agricultural residues provides a very cheap and environmentally friendly alternative for producing foods with high nutritional value. This study was conducted to determine the influence of different straw substrates and cropping container on the yield, nutritional, phytochemical and polysaccharide degrading potentials of Pleurotus ostreatus. Six sample substrates: Andropogon gayanus, Zea mays and Pennisetum purpureum straws and their combinations were used. Known weight of each substrate and substrates combinations were made in 3 replications and placed into two and half (2.5) litres perforated and non-perforated transparent plastic buckets. Experiment was laid out in a Completely Randomized Design (CRD). Data analysis was carried out using one way analysis of variance (ANOVA) while mean separation was done by Duncan Multiple Rang Test (DMRT). Results showed that P. ostreatus grown on Andropogon gayanus substrate in non-perforated (Non-perf AND) buckets gave the highest (580.11g/kg and 96.69%) yield and biological efficiency (BE %) respectively. Results of yield and BE% of P. ostreatus with respect to substrate combinations showed P. ostreatus grown on combined Pennisetum and Zea mays in non-perforated buckets (Non-perf.PEN/ZEA) gave the highest yield (573.66g/kg) and BE% (95.61%) respectively. The overall result on yield and BE% indicated that A. gayanus straw substrate supported highest yield (1040.66g/kg) and BE% (86.72%) respectively. Results of proximate analysis showed that P. ostreatus is a good source of crude protein, fat, dietary fibre and carbohydrates. The highest crude protein (26.58+0.00%) was recorded in A. gayanus, fat (8.50%) in combined Andropogon and Zea mays straw, fibre (8.50%) in combined Andropogon and Zea mays straw and carbohydrates (44.95%) in combined Pennisetum and Zea mays. The result of the vitamin analysis clearly shows that P. ostreatus grown on these substrates are very rich in vitamins and other nutrients hence regarded as good quality food materials. The result of the phytochemicals analysis showed that the mushrooms contained moderate amount of alkaloids, tannins, flavonoids, saponins and phenols.  P. ostreatus showed high polysaccharide degrading potentials on all the substrates compared to fresh/unused substrates suggesting its importance in environmental management strategies. Therefore the use of Andropogon gayanus straws in non- perforated plastic buckets or trays should be adopted in the commercial production of P. ostreatus fruit bodies.