对甲苯磺酸耦合碱性过氧化氢预处理对不同木质纤维素生物转化的影响  

Effect of p-TsOH combined with AHP pretreatment on biotransformation of different lignocellulose

作　　者：管舒仪 窦妍[1,2] 蔡晓丹 陈欣玥 张笑 杨明琰[1,2] GUAN Shuyi;DOU Yan;CAI Xiaodan;CHEN Xinyue;ZHANG Xiao;YANG Mingyan(School of Water and Environment,Chang’an University,Xi’an,Shaanxi 710054,China;Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education,Xi’an,Shaanxi 710054,China)

机构地区：[1]长安大学水利与环境学院,陕西西安710054 [2]旱区地下水文与生态效应教育部重点实验室,陕西西安710054

出　　处：《西北农林科技大学学报（自然科学版）》2022年第6期71-81,共11页Journal of Northwest A&F University(Natural Science Edition)

基　　金：陕西省重点研发计划-社会发展项目(2021SF-443);陕西省自然科学基金项目(2018JQ4042)。

摘　　要：【目的】研究对甲苯磺酸(p-toluenesulfonic acid,p-TsOH)耦合碱性过氧化氢(AHP)预处理对不同木质纤维素酶解率及乙醇产率的影响,为农林废弃物纤维素生物转化提供理论依据。【方法】以芒草秆、小麦秸秆和杨木为供试材料,分别采用p-TsOH处理(质量分数70%p-TsOH水溶液于80℃处理20 min)以及p-TsOH耦合AHP两步处理(先用质量分数70%p-TsOH水溶液于80℃处理20 min,之后用pH 11.5、体积分数2%H_(2)O_(2)于50℃、120 r/min恒温振荡器中反应12 h)2种方法对3种材料进行预处理,分析不同预处理方法对3种材料化学组成、形态结构(扫描电镜观察、傅里叶变换红外光谱、X-射线衍射、结晶度、保水值)的影响,并研究纤维素酶添加量(5,10,15 FPU/g,以纤维素质量计算)及不同发酵工艺(同步糖化发酵、分步糖化发酵)对p-TsOH耦合AHP两步处理3种材料纤维素酶解率及乙醇产率的影响。【结果】采用p-TsOH处理以及p-TsOH耦合AHP两步处理后,芒草秆、小麦秸秆和杨木中的半纤维素和木质素含量明显降低,纤维素含量明显提高,其中p-TsOH耦合AHP两步处理的效果更明显,该法处理的芒草秆、小麦秸秆和杨木的木质素脱除率分别为97.01%,96.50%和94.01%,半纤维素脱除率分别为82.50%,84.21%和81.19%,纤维素保留率分别为87.97%,87.85%和90.53%。采用p-TsOH处理以及p-TsOH耦合AHP两步处理后,芒草秆、小麦秸秆和杨木的微观结构、傅里叶变换红外光谱、X-射线衍射图谱发生了明显变化,结晶度及保水值均明显增加。纤维素酶添加量5 FPU/g、酶解72 h时,芒草秆和小麦秸秆的酶解率均超过90%,而杨木的酶解率为78%;纤维素酶添加量15 FPU/g、酶解12 h时,芒草秆、小麦秸秆的酶解率达到100%,杨木的酶解率为73%;纤维素酶添加量10 FPU/g、酶解24 h时,芒草秆、小麦秸秆和杨木的酶解率均达到95%以上。当底物质量浓度为130 g/L、纤维素酶加量为10 FPU/g、发酵96 h�【Objective】The effects of p-toluenesulfonic acid(p-TsOH)combined with alkaline hydrogen peroxide(AHP)pretreatment on substrate enzymatic digestibility(SED)and ethanol yield of different lignocellulose were studied to provide basis for resource conversion of cellulose from agricultural and forestry residues.【Method】Miscanthus straw,wheat straw and poplar were pretreated by 70%p-TsOH at 80℃for 20 min and a two-step pretreatment using sequential 70%p-TsOH at 80℃for 20 min and 2%H_(2)O_(2) with pH of 11.5 in a 120 r/min constant temperature oscillator at 50℃for 12 h.The effects of different pretreatments on chemical composition,morphology and structure including SEM,FT-IR,XRD,crystallinity and water retention value(WRV)of the three materials were analyzed.The effects of cellulase dosage(5,10 and 15 FPU/g,in terms of cellulose mass)on SED and different fermentation processes of simultaneous saccharification and fermentation(SSF)and separate hydrolysis fermentation(SHF)on ethanol yield were studied as well.【Result】After different pretreatments,hemicellulose and lignin contents of all three materials decreased,while cellulose content increased significantly.After the two-step pretreatment,97.01%,96.50%and 94.01%of lignin and 82.50%,84.21%and 81.19%of hemicellulos were removed from Miscanthus,wheat straw,and poplar,respectively,and the cellulose recovery reached 87.97%,87.85%and 90.53%.After two different pretreatments,the microstructure,FT-IR and X-ray diffraction pattern of three materials changed significantly and the crystallinity and WRV increased significantly.When cellulase dosage was 5 FPU/g at 72 h,SED of Miscanthus straw and wheat straw was over 90%,while that of poplar was 78%.When cellulase dosage was 15 FPU/g at 12 h,SED of Miscanthus straw and wheat straw reached 100%,and that of poplar was 73%.When cellulase dosage was 10 FPU/g at 24 h,SED of all three materials reached over 95%.The ethanol yields of SSF of three two-step pretreated materials at 96 h were 92.63%,90.07%and 88.00%with subst

关 键 词：木质纤维素 对甲苯磺酸 碱性过氧化氢 乙醇发酵 

分 类 号：TQ353.4[化学工程]