木质素基表面活性剂对玉米秸秆纤维素酶水解的促进作用  

Enhancement of lignin-based surfactants on the enzymatic hydrolysis of corn stover

作　　者：赖晨欢[1] 高子琦[1] 唐硕[1] 勇强[1] 

机构地区：[1]南京林业大学化学工程学院,南京210037

出　　处：《林业工程学报》2016年第6期102-107,共6页Journal of Forestry Engineering

基　　金：江苏省自然科学青年基金项目(BK20150874);国家自然科学基金面上项目(31570561)

摘　　要：木质素是影响木质纤维原料酶水解的关键因素。本研究通过聚乙氧基接枝修饰制备木质素基表面活性剂,并探究其对预处理玉米秸秆纤维素酶水解的影响机制。结果表明,木质素基表面活性剂对蒸汽爆破预处理玉米秸秆酶水解有显著的促进作用。木质素基表面活性剂的最适添加量为0025 0 g/g(以纤维素计)。在最适添加量下,碱木质素基表面活性剂及醇溶木质素基表面活性剂使得蒸汽爆破预处理玉米秸秆72 h酶水解得率分别提高了275%和281%。与此同时,72 h酶水解液中外切葡聚糖酶酶活力分别提高了493%和410%;β-葡萄糖苷酶酶活力分别提高了196%和137%。说明木质素基表面活性剂可减少纤维素酶的无效吸附,从而起到对酶水解的促进作用。Lignin has been considered as a key factor that influences the enzymatic saccharification of lignocellulosic materials by physically blocking and causing ineffective adsorption of the cellulase enzyme. The extent of its inhibition on the enzymatic hydrolysis is determined by the content and distribution on the substrates as well as the physicochemical properties of lignin （e.g., hydrophobieity, surface charges amount, functional groups）. Delignifieation methods and lig- nin modification strategies have been applied to relieve the lignin inhibition. To explore the potential application of lignin modification methods on reducing lignin inhibitory effects, two surfactants were prepared by grafting polyoxyethylene ether on lignins in the present work. The effects of lignin-based surfaetants on the enzymatic hydrolysis of steam explosion pretreated corn stover （SEPCS） were evaluated. The results indicated that the lignin-based surfactants remarkably en- hanced the enzymatic hydrolysis of SEPCS. The optimal load of lignin-based surfactants was 0. 025 0 g/g （ based on the dry weight of cellulose）. The 72 h hydrolysis yields of SEPCS have increased by 27. 5% and 28. 1% with the addition of alkali lignin-based and ethanol-extracted lignin-based surfaetant, respectively. Meanwhile, the free exoglueanase activities increased 49.3% and 41.0% ; the free fl-glucosidase activities increased 19. 6% and 13.7% in the 72 h enzy- matic hydrolyzates of SEPCS with the addition of alkali lignin-based and ethanol-extracted lignin-based surfactant, re- spectively. These results might be attributed to that the lignin-based surfactant reduced the ineffective adsorption of en- zyme during enzymatic hydrolysis.

关 键 词：木质素 接枝修饰 表面活性剂 纤维素酶水解 酶吸附 

分 类 号：TQ35[化学工程]