LAUSR

Abstract Hypericum perforatum residue waste, which is obtained after the extraction of a traditional Chinese herbal medicine, contained a high concentration of cellulose that can be used for ethanol production. The addition of other wastes with high nitrogen content and the effect of residual medical components on ethanol fermentation were investigated. Among inorganic nitrogen compounds, such as (NH4)2SO4, certain organic solid waste dregs including bean dregs and Salviae miltiorrhiza dregs (another Chinese traditional herb), and ethanol fermentation residue from food waste, S. miltiorrhiza dregs can effectively improve ethanol production. Ethanol concentration after 72 h with added S. miltiorrhiza dregs was 6.0 g/L, which was 44.8% of the theoretical yield. The remaining medical components on ethanol fermentation did not show any inhibitory effect. The bioconversion of traditional Chinese medicine dregs to ethanol can be a new approach for medicine waste utilization.