固态发酵中纤维素基质降解过程初步研究

Experimental Observation on Cellulosic Biodegradation in Solid State Fermentation

利用斜卧青霉(Penicillium decumbens JUA10)对汽爆麦草和淀粉质的混合基质进行固态发酵,通过分析各种成份及酶活力变化,研究了各成份的降解速率,并探讨了纤维素、半纤维素降解与纤维素酶、半纤维素酶酶活力的关系. 纤维素基质固态发酵中木质纤维素的降解过程实际是同步糖化发酵过程,还原糖不会积累形成对纤维素酶、半纤维素酶的反馈抑制;纤维素降解与纤维素酶的酶活性、半纤维素的降解与半纤维素的酶活性不成正比. 木质纤维素的降解难主要是木质纤维素结构造成的. 半纤维素的降解甚至比纤维素降解更慢,淀粉容易降解,木质素几乎不降解.

A mixed medium of steam exploded wheat straw (SEWS) and wheat bran was fermented in solid state by Penicillium decumbens JUA10. Various degraded constituents and activities of enzymes were analyzed. The process of biodegradation of cellulose is actually simultaneous saccharification and fermentation, and feedback inhibition of reducing sugar on cellulose or hemicelluloses may not heavily occur. Biodegradation of cellulose, hemicellulose was not proportional to activities of cellulase and hemicellulase. The compact structure of lignocellulose was the major cause for the low degradation rate of cellulose and hemicellulose. Hemicellulose was degraded even more slowly than cellulose. Starch was degraded easily while lignin was not degraded.