桉木氨水浸渍预处理响应面优化提高酶解效率

摘要

The methodology of soaking eucalypt wood in aqueous ammonia (SAA) as a pretreatment for enhancing production of fermentable sugars from enzymolysis process was investigated in this study. Various pretreatment conditions including temperature, time and dosage of aqueous-ammonia on the enzymatic digestibility were optimized using response surface methodology. An enzymatic digestibility of 31.7%was obtained when the eucalypt fibers were pretreated at the optimal conditions: 80.0% ammonia;temperature of90°C; and,a duration of 11h. The fourier transform infrared spectroscopy(FTIR) analysis indicated that hemicellulose degradation and lignin structure transformation occurred during SAA pretreatment.%采用氨水中温浸渍(SAA)方法对桉木进行预处理，以期提高其后续酶水解效率。以响应面法主要预处理条件进行优化，以期筛选出SAA预处理的最优工艺条件。结果表明：最佳预处理工艺为氨用量80%、时间11 h、温度90℃，在此条件下预处理物料的后续酶解转化率可达31.7%。对预处理物料的分析表明：在SAA预处理过程中，可在不损失纤维素的前提下脱除木素51%，而且主要是紫丁香基型和愈疮木基型木素降解溶出，半纤维素主要是木聚糖也有部分降解溶出。木素及半纤维素的降解、纤维素结晶度的降低都有利于后续的酶水解。