Production of spent mushroom substrate hydrolysates useful for cultivation of Lactococcus lactis by dilute sulfuric acid, cellulase and xylanase treatment

► An L9 (34) orthogonal experiment was performed to optimize the acid treatment process. ► The dilute sulfuric acid could be reused for the pretreatment of SMS at least four times. ► Cellulase and xylanase could be used for the hydrolysis of the acid pretreatment SMS. ► Dilute acid pretreated SMS hydrolysates could be used as the carbon source for cultivation of Lactococcus lactis subsp. lactis W28. ► The alkalis used for neutralizing the hydrolysates resulted in difference in the cell density.