Abstract: Using Pleurotus tuoliensis and white Hypsizygus marmoreus spent mushroom substrate as the cultivation medium of Pleurotus ostreatus in different proportions, the study observed the growth and enzyme activity of P. ostreatus mycelium and discussed on the effects of spent mushroom substrate on the growth of P. ostreatus mycelium. The experimental results showed that after adding two types of spent mushroom substrate, the growth rate, mycelial growth potential, and bottle filling time of P. ostreatus mycelium were better than the control group. The carboxymethyl cellulase reached its highest value at 2.61 U/mL when the addition amount of white H. marmoreus spent mushroom substrate was 45%; when the addition amount of white H. marmoreus spent mushroom substrate was 30%, the highest activity of xylanase was 9.02 U/g; the highest laccase activity was 263.72 U/L with 60% white H. marmoreus spent mushroom substrate; the highest catalase activity was 13.44 U/g when the amount of P. tuoliensis spent mushroom substrate was 60%.

Key words: spent mushroom substrate, Pleurotus ostreatus, cultivation medium, mycelial growth, enzyme activity assay