Lignin Promotes Mycelial Growth and Accumulation of Polyphenols and Ergosterol in Lentinula edodes

It has been demonstrated that lignin was efficiently degraded byLentinula edodes(L. edodes). However, the process of lignin degradation and utilization byL. edodeshas not been discussed in detail. Therefore, the effects of lignin onL. edodesmycelium growth, chemical compositions, and phenolic profiles were investigated herein. It has been revealed that 0.10% lignin acted as the most effective concentration to accelerate mycelia growth, which yielded the highest biomass of 5.32 ± 0.07 g/L. Furthermore, a 0.10% concentration of lignin promoted the accumulation of phenolic compounds, especially protocatechuic acid, with peak value of 48.5 ± 1.2 μg/g. In contrast, the higher concentration of lignin (0.20%) exerted an inhibitory effect on the growth ofL. edodes. Overall, the application of lignin at the optimal concentration of 0.10% could not only enhance the mycelial growth but also accumulate the phenolic acids and raise the nutritional and medical values ofL. edodes.Keywords:lignin;shiitake mushroom;biomass;phenolic compound