Quantitative and visual analysis of enzymatic lignocellulose degradation

•Miscanthus, switchgrass and wheat straw were enzymatically hydrolyzed.•Tween 80, peptone and ethanol have been tested as hydrolysis additives.•SEM images have been taken in order to evaluate the degree of decomposition.

Lignocellulosic ethanol is a promising second-generation biofuel. However, production still faces huge challenges, especially in the field of pretreatment. Mechanical and enzymatic methods have been widely investigated, still little is known about the process of decomposition. Therefore, in this work three substrates: Miscanthus, switchgrass and wheat straw have been enzymatically hydrolyzed, after steam explosion treatment. Additionally, three additives Tween 80, peptone and ethanol have been tested for their influence on the enzymatic hydrolysis. The degree of decomposition has been evaluated by the amount of released sugars and by examination of the fiber structure by scanning electron microscopy. The images gave highly interesting insights into the degradation of the lignocellulosic scaffold and the weakening of the cellular cohesion. Hereby, the smaller fragments with epidermal structures showed a much higher degree of destruction than the stem parts. Therefore mechanical disintegration and use of certain additives is highly recommended as a pretreatment method.

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