Effect of cultivating Pleurotus ostreatus on substrates supplemented with herb residues on yield characteristics, substrates degradation, and fruiting bodies' properties.

BACKGROUND

Inappropriate disposal of herb residues in China has caused major problems for the immediate environment and to human safety. Here, three herb residues, compound Kushen injection (CKI), Qizhi Tongluo capsule (QTC), and Shenbai Shuxin capsule (SSC), were applied as substrates to corncob at various ratios (30:60, 45:45, and 60:30) for the propagation of the mushroom Pleurotus ostreatus. The effects of supplementation using herb residues on yield, biodegradation ability, bioactive compounds, antioxidant properties, and safety of P. ostreatus were assessed.

RESULTS

Different spawn running times were observed using growth medium, whereas 45CKI, 60QTC, and 30SSC media were determined as optimal-performing substrate combinations, resulting in yields of 843 g kg , 828 g kg , and 715 g kg respectively. Biodegradation analysis of consumed substrates revealed a significant decrease in cellulose and hemicellulose levels compared with lignin. Furthermore, chemical analysis of fruiting bodies revealed that the 45CKI and 60QTC substrates resulted in higher total phenol, flavonoid, terpenoid, and vitamin C levels, but significantly reduced water-soluble polysaccharides compared with the corncob medium. The methanol extract of fruiting bodies grown on substrates containing herb residues exhibited higher antioxidant properties than the control, as it was more effective in scavenging 2,2-diphenyl-1-picrylhydrazyl radicals, had greater reducing power, and more strongly inhibiting lipid peroxidation. Furthermore, high-performance liquid chromatography studies indicated that fruiting bodies did not generate matrine (a specific toxin produced in Kushen) when cultivated using the CKI substrate.

CONCLUSIONS

P. ostreatus cultivation on substrates mixed with herb residues facilitates herb residue management as well as bioactivity-rich and non-toxic fruit body formation. © 2020 Society of Chemical Industry.