Application of acidic wastewater from monosodium glutamate process in pretreatment and cellulase production for bioconversion of corn stover – Feasibility evaluation

Reducing process cost of the bioconversion of lignocellulosic is a challenge. In China, abundant acidic wastewater from monosodium glutamate production is difficult to treat, leading to serious water pollution. In this study, acidic liquid (ALC) and solid residue components (SC) obtained from the wastewater were used in pretreatment and cellulase production, respectively, to evaluate their potential in bioconversion of corn stover. Optimum pretreatment conditions (170 °C, 60 min, 0.75% ALC) were identified by a central composite design method. There were little difference in the chemical components and digestibility (above 84%) of between ALC and H2SO4-treated corn stover, and amounts of HMF and furfural in liquor after pretreatment with ALC and H2SO4 under optimum conditions. SC can be substituted for (NH4)2SO4 in liquor fermentation to produce cellulase with comparable filter paper (about 10.7 U/ml) and β-glucosidase (about 2.7 U/ml) activities.