摘要
用经过两步碱法(氢氧化钠-氢氧化钙)预处理的玉米秸秆为原料,以树干毕赤酵母为发酵菌株,分别研究在三角瓶体系和发酵罐体系中,未水洗和水洗物料在不同pH下对玉米秸秆半同步糖化共发酵的影响.结果表明:在三角瓶体系中,未水洗物料在pH 4.8下预酶解48 h之后维持pH不变,乙醇产率为0.193 g/g(以物料中纤维素和半纤维素含量计,下同),预酶解48 h之后将pH调至6.0时乙醇产率为0.234 g/g,改变pH对乙醇产率有较大提高,提高了21.24%;水洗物料在pH 4.8下预酶解48 h之后维持pH不变时乙醇产率为0.287 g/g,预酶解48 h之后将pH调至6.0时乙醇产率为0.292 g/g,改变pH对乙醇产率的提高不明显.同时进行了3 L发酵罐的放大实验,在与三角瓶同样的反应条件下,未水洗和水洗物料的乙醇产率分别为0.220和0.234 g/g.综合考虑水洗所带来的环境污染等问题后发现,未水洗物料同样可用于乙醇发酵.
Corn stover pretreated with two-step alkaline method(sodium hydroxide combined with calcium hydroxide)was used as material.Pichia stipitis was used as fermentation strain.The influence of washed and unwashed material under different pH conditions on the semi-simultaneous saccharification and co-fermentation of corn stover were investigated.The experiment results showed:in erlenmeyer flask system,the ethanol yield of unwashed materials was 0.193 g/g after pre-enzymatic hydrolysis for 48 h under pH 4.8 and then maintained the pH(based on the cellulose and hemicellulose in the material.The same is true below).The ethanol yield of unwashed materials was 0.234 g/g after pre-enzymatic hydrolysis for 48 h under pH 4.8 and then changed the pH to 6.0.Changing the pH can increased the ethanol yield by 21.24%.The ethanol yield of washed materials after pre-enzymatic hydrolysis for 48 h under pH 4.8 and then maintained the pH was 0.287 g/g.The ethanol yield of washed materials after pre-enzymatic hydrolysis for 48 h under pH 4.8 and then changed the pH to 6.0 was 0.292 g/g.Changing the pH can not improve the ethanol yield obviously.Meanwhile,3 L fermenter enlarger experiment was also carried out.Under the same reaction condition with erlenmeyer flask system,the ethanol yields of washed and unwashed materials were 0.220 and 0.234 g/g,respectively.Taking the environmental pollution caused by washing into consideration,unwashed material can also be used for ethanol production.
作者
朱圆圆
卢仟旭
朱均均
徐勇
余世袁
ZHU Yuanyuan;LU Qianxu;ZHU Junjun;XU Yong;YU Shiyuan(School of Grain Science and Technology,Jiangsu University of Science and Technology,Zhenjiang 212004,China;College of Chemical Engineering,Nanjing Forestry University,Nanjing 210037,China)
出处
《江苏科技大学学报（自然科学版）》
CAS
2020年第1期98-104,共7页
Journal of Jiangsu University of Science and Technology:Natural Science Edition
基金
江苏科技大学引进博士科研启动经费资助项目。
关键词
半同步糖化共发酵
水洗/未水洗
玉米秸秆
发酵罐
树干毕赤酵母
semi-simultaneous saccharification and co-fermentation
washed/unwashed
corn stover
fermenter
Pichia stipitis
