Recycling of Flammulina filiformis Mushroom Root Waste as Novel Raw Material for the Cultivation of F. filiformis

With the increasing yield of Flammulina filiformis, spent mushroom root waste (MRW) has emerged as a major agricultural residue in F. filiformis production. In this paper, MRW was used as a new supplement for substrate mixtures to produce F. filiformis. Thirteen formulations and a control were designed to evaluate 37 cultivation and quality indices, including the physicochemical properties of the substrate, mycelial growth and development, yield, biological efficiency, fruiting body appearance quality, and nutritional quality. The cultivation substrate, including 1% (P4) or 3.1% (P8) MRW, was found to improve the yield and the biological efficiency while having no effect on or even improving some cultivation and nutritional indices, such as the growth rate of the length of the stipe (SLGR), the length of the stipe during harvest time (SL), and the crude fiber content (CFC), crude protein content (CPC) and phenylalanine in the fruiting body, compared with the control. In addition, the content of MRW had a significant impact on 37 cultivation indices except for FWC. However, in terms of correlation, it was only substantially correlated with the content of eight amino acids, four substrate indices, and two growth and development indices. The findings above indicated that adding 1-5% MSW could improve the mycelial growth rate, yield, biological efficiency, and quality of F. filiformis, which was a cost-effective method to recover MSW in a timely manner.