碳源对平菇选择性降解稻草木素及其后续酶解性能的影响

前期研究发现,平菇预处理稻草表现出比较好的脱木素选择性和纤维素酶水解效果。为了使预处理后的稻草在纤维素酶水解过程中得到更多的单糖,通过向平菇预处理稻草固体培养基中添加麸皮、玉米皮和木聚糖,研究外加碳源对平菇降解稻草木素的选择性及后续酶水解效果的影响。结果表明,添加适量的麸皮和木聚糖可提高平菇处理稻草的脱木素选择性。麸皮和木聚糖添加量为稻草粉的10%时,脱木素选择系数分别由对照的1.86增加至2.58和2.03;预处理样品酶解后原料中总糖的46.8%和45.9%转化为可发酵单糖,分别比对照的35.5%提高了30%和28%。添加玉米皮对平菇预处理酶解效果影响相对较小,添加量为5%时,预处理样品酶解后总糖转化率仅比对照提高15%,增加添加量酶解总糖转化率反而低于对照样品。

Effects of Carbon Resource on Selectivity of Delignification in Pleurotus ostreatus Pretreatment of Rice Straw for Enzymatic Hydrolysis

Effects of various carbon resources, i.e. bran, com husks and xylan on the selectivity of delignification during Pleurotus ostreatus pretreatrnent of rice straw for enzymatic hysrolysis were investigated. The results indicated that both the selectivity of delignification and total sugar recovery were significantly improved by the addition of bran or xylan. The selectivity of delignification was improved from 1.86 of control up to 2.58 and 2.03, respectively, as 10% of bran and corn husks （based on rice straw） were added during the pretreatment; in the meantime, 46.8% and 45.9% polysaccharides in rice straw converted into fermentable sugars by enzymatic hydrolysis, which meant 30% and 28% sugar recovery enhancement by the addition of bran and corn husks, respectively. As comparision, the total sugar conversion of enzymatic hydrolysis only improved 15%, to 42.8%, when 5% （on rice straw） core husks were added into the system.