纤维素不同途径水解酸化效果对比研究

农作物秸秆结构复杂,酸化效果可能与传统糖类物料不一致。为方便考察纤维素类物料厌氧酸化效果,文章选取成分相对单一的滤纸为原料,考察了酶活浓度、反应时间、酵母菌接种量(F/M)等因素对纤维素经纤维素酶和酵母菌联合作用后的乙醇、乙酸产量的影响,及对厌氧发酵过程的影响分析。结果表明,当纤维素酶单独作用时,酶活浓度120 U/g、温度50℃、pH值4.8、水解24 h时可获得最大葡萄糖产率:73.7 mg/g(转化率为24.9%);纤维素酶和酵母菌分步糖化发酵(separate hydrolysis and fermentation,SHF)工艺中,F/M值为2:1、反应96 h可得最大乙醇产率:119.3 mg/g(转化率为42%);纤维素酶和酵母菌同步糖化发酵(simultaneous saccharification andfermentation,SSF)工艺中,F/M值为1:2、反应120 h得到最大乙醇产率:396.0 mg/g(转化率为58.2%)。F/M值为2:1、反应120 h时,SSF工艺比SHF工艺的乙醇产量提高了34.91%。

Comparative Study on Cellulose Hydrolysis and Acidification in Different Pathways

Complicated structure of crops straw may arouse uncorresponding acidification result with traditional sugar crops,To study the acidification effect of lignocellulosic materials conveniently,filter paper which is relatively simple was selected as raw material,to investigate the effects of activity of cellulose,reaction time and ratio of cellulose to yeast inoculation(F/M)on production of ethanol and acetic acid which were produced from cellulose after the joint action of cellulose and yeast as well as anaerobic fermentation process.Results indicated that the maximum glucose production was 73.7 mg/g(24.9% of transformation ratio,TR)in the condition of enzymatic concentration 120 U/g,50 ℃,pH 4.8 and 24 h of hydrolysis.The maximum ethanol production was 119.3 mg/g(42% of TR)in the condition of F/M ratio of 2:1,reaction time 96 h in separate hydrolysis and fermentation(SHF)process corresponding to 396 mg/g(58.2% of TR)in the condition of F/M ratio of 1:2,reaction time 120 h in simultaneous saccharification and fermentation(SSF)process.Ethanol production was enhanced by 34.91% through SSF process than SHF in the condition of F/M ratio of 2:1 and reaction time120 h.