Biotransformation of wheat straw to bacterial cellulose and its mechanism.

An ionic liquid [AMIM]Cl was used to pretreat wheat straw with an aim to remarkably improve enzymatic hydrolysis rate and yield of fermentable sugars. Some influence factors including dosage of straw, particle size of straw meal as well as pretreatment time and temperature were investigated. After optimization, the hydrolytic efficiency of regenerated straw increased obviously as compared to untreated materials, and the sugar yield of straw was 71.2% after pretreatment in [AMIM]Cl at 110 °C for 1.5 h with a 3 w/w% straw dosage, 3.6 times higher than that of untreated straw (19.6%). The reason behind the acceleration of enzymatic hydrolysis was discussed by the analysis of SEM, XRD and FTIR. The yield of bacterial cellulose obtained in straw hydrolysates was higher than that in glucose-based media. This may be due to the presence of other complex components in the hydrolysate that would enhance the formation of bacterial cellulose.