Rosa sterilis S.D.Shi Pomace Enhances Mycelial Growth and Extracellular Enzyme Activity of Phallus rubrovolvatus Through Substrate Optimization

Abstract

Rosa sterilis S.D.Shi pomace (RSP), a nutrient-rich by-product of fruit processing, holds considerable potential for valorization. Given the increasing interest in recycling agricultural residues for edible fungi cultivation, RSP may represent a viable, sustainable substrate component. This study evaluated the effects of partial substitution of wood chips with RSP on the mycelial growth of Phallus rubrovolvatus and aimed to identify an optimal substrate formulation. The results showed that the addition of 10% and 20% RSP to the substrates significantly promoted mycelial growth and shortened the mycelial colonization time by 4–5 days. The addition of RSP increased total phosphorus and potassium contents by 12.2%–65.9% and by 0.4- to 4.4-fold, respectively. No significant differences in the C:N ratio were observed among treatments with 5%, 10%, and 20% RSP compared to the control. Extracellular enzyme activities varied across treatments, with the 10% RSP group yielding the maximum increments in pectinase (45.9%), laccase (11.9%), xylanase (12.5%), and protease (35.6%). Although substrate pH remained relatively stable, the total organic acid content decreased, whereas the levels of citric, acetic, and succinic acids increased. Overall, 10% RSP substitution significantly enhanced mycelial growth and enzymatic activity. These findings suggest that RSP improves the mycelial ability to degrade and assimilate substrate nutrients, demonstrating its potential as an effective and sustainable substrate amendment for P. rubrovolvatus cultivation. This study provides a practical strategy for agricultural waste valorization and supports the circular utilization of biomass resources.