【作者】 董庸行；

【导师】 贾新成； 杜风光； 宋安东；

【作者基本信息】 河南农业大学 ， 微生物学， 2007， 硕士

【摘要】 本文对利用玉米秸秆生产纤维燃料乙醇的关键技术进行了研究,包括秸秆糖化液中有毒物质脱除和提高酵母菌发酵性能两个主要方面,以提高发酵的结果,为纤维燃料乙醇的产业化奠定基础。对糖化液进行了分析表明,糖成分主要有葡萄糖、木糖、甘露糖、半乳糖、阿拉伯糖等;D-葡萄糖和木糖的比例约为1.22,二者占总还原糖76.18%左右;糖化液中乙酸含量为4.68g/L,糠醛含量为0.20g/L。嗜鞣管囊酵母P-01单独发酵木糖的糖醇转化率为15.23%;P-01发酵纯糖的糖醇转化率为28.54%;P-01发酵玉米秸秆糖化液的糖醇转化率为17.36%,在玉米秸秆糖化液中乙酸是酵母菌发酵的主要抑制物质,而糠醛对酵母菌无显著影响。对糖化液的脱毒试验结果表明,通过提高发酵培养基中的pH(由5.0升至5.5),P-01的糖醇转化率可从20.61%提高到23.58%;用熟石灰对糖化液脱毒处理,P-01的糖醇转化率可从18.90%提高到21.57%;蒸煮糖化液脱毒,P-01的糖醇转化率由24.12%提高到25.25%;糖化液中0.1g/L的乙醛能使P-01的糖醇转化率从23.06%,提高到24.00%,0.1g/L的沸石可使P-01的糖醇转化率从16.95%提高到18.94%,1g/L的活性炭可使P-01的糖醇转化率从16.95%提高到18.39%。在提高酵母发酵性能方面,在酶解时用磷酸缓冲液,更适合P-01发酵玉米秸秆糖化液;适合P-01发酵玉米秸秆糖化液的培养基配方为:酵母膏0.03 g/100ml,蛋白胨0.05 g/100ml,尿素0.02 g/100ml,磷酸氢二铵0.01 g/100ml,吐温80 25μm/100ml,聚乙烯醇2.5mg/100ml,L-谷氨酰胺62.5mg/100ml,pH5.0;添加油酸对酵母菌发酵结果的影响不明显;在36h时补料,发酵结束的乙醇含量为2.05%(v/v)比对照的乙醇含量1.54%(v/v)高出0.51百分点,P-01的糖醇转化率为28.23%,略低于对照的28.71%。更多还原

【Abstract】 In this paper,the key technology of fuel ethanol produced from corn stalk material by Pachysolen tannophilus P-01 was studied.Including two main aspects,one was the detoxification of corn stalk saccharified liquid and another was enhancing fermentation of the yeast,improving the results,and putting the way for fuel ethanol industry.As analyzing the saccharified liquid,the main sugar was glucose,xylose,mannose, galactose,arabinose et al.;the ratio of D-glucose to xylose was about 1.22,D-glucose and xylose is accounting for about 76.18%of total sugar;the acetic acid and furfural at concentrations of 4.68g/L and 0.20g/L,respecttively.Fermentation of xylose by P-01,and the ethanol conversion rate was 15.23%; co-fermentation of glucose and xylose P-01,and the ethanol conversion rate was 28.54%;and fermertation of saccharified liquid by P-01,and the ethanol conversion rate was 17.36%.In the saccharified liquid,P-01 was inhibited by acetic acid and not by furfural.The results of detoxification to the saccharified liquid show that,adjusting pH from 5.0 to 5.5 to the saccharified liquid,the ethanol conversion rate of P-01 increased from 20.61%to 23.58%;treatment to the saccharified liquid by hydrated lime,the ethanol conversion rate of P-01 increased from 18.90%to 21.57%;detoxification by cooking to the saccharified liquid,the ethanol conversion rate of P-01 increased from 24.12%to 25.25%;addition 0.1g/L acetaldehyde,0.1g/L zeolite,1g/L activated carbon can increase The ethanol conversion rate from 23.06%to 24.00%,from 16.95%to 18.94%,from 16.95%to 18.39%,respecttiveiy.For improving fermentation of P-01,choose the phosphoric acid buffer is more suitable for co-fermentation to fuel ethanol production from corn stalk;the medium formulation which is suitable for fermentation of saccharified liquid by P-01 is yeast extract 0.03 g/100ml,peptone 0.05 g/100ml,urea 0.02 g/100ml,（NH4）₂PO₄ 0.01 g/100ml,tween 80 25μm/100ml,PVA 2.5mg/100ml,L-glutamine 62.5mg/100ml, pH5.0.The impact of oleic acid on fermentation is weak;when 36h feeding batch culture,at the end of fermentation the ethanol concentration is 2.05（v/v）,0.51 higher than the ethanol concentration of control,the ethanol conversion rate of P-01 was 28.23%,slightly lower than 28.71%of the control.更多还原