Bacterial cellulose production from ethylenediamine pretreated Caragana korshinskii Kom

Abstract

In this study, three different pretreatment technologies (hydrothermal, NaOH, and ethylenediamine (EDA) pretreatment) were investigated to improve the efficiency of the enzymatic conversion of Caragana korshinskii Kom. (CKK). The effects of the pretreatment conditions on the composition, structure, and enzymatic hydrolysis of CKK were evaluated. The results indicated that EDA pretreatment was more effective in promoting CKK digestibility than the other pretreatments. EDA exhibited a good delignification ability (up to 72.8%) and a strong de-crystallization effect (up to 29.9%) compared to hydrothermal and NaOH pretreatment. The best result for the cellulose enzymatic conversion (88.0%) was obtained at 210 °C for 40 min with 30 mL EDA. Using of the EDA-pretreated CKK as a substrate for bacterial cellulose (BC) production indicated that a lower nutrient level in the enzymatic hydrolysate medium could be a key factor that impedes the fermentation performance of Gluconacetobacter xylinus. The addition of extra nutrients promoted BC production efficiency, and under optimized conditions, the BC yield was 4.6 g/L.