Highly efficient pretreatment at low enzyme loading from reed: Synergy of liquid hot water–ammonia/oxygen and non-ionic surfactants as enzymatic hydrolysis additive

Abstract

This study aimed to obtain a pretreatment and enzymatic hydrolysis method with high enzymatic digestibility at low enzyme loading from reed. Meanwhile, the three major components of reed were separated to be high-value utilized. The combination of liquid hot water–ammonia/oxygen pretreatment and non-ionic surfactants-enhanced enzymatic hydrolysis was studied to solve the problem of non-separation of hemicellulose and lignin in the pretreatment of single-step ammonia/oxygen method. The promoting effect and mechanism of non-ionic surfactants on enzymatic hydrolysis were also explored. Under the optimal conditions, 86.74% of glucan was retained and 65.48% of lignin was dissolved for high-value utilization. The addition of polyethylene glycol increased the enzymatic digestibility of pretreated reed to 97.13% at 9 filter paper units/g–solid. Therefore, this LHW–NH3·H2O/O2 pretreatment and enzymatic hydrolysis adding PEG 6000 method is a low-cost, green, and highly efficient method for fermentable sugar, hemicellulose, and modified lignin production.