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固定化运动发酵单胞菌乙醇发酵研究 总被引:3,自引:2,他引:3
以运动发酵单胞菌(zymomonas mobilis 10225)为菌种。以葡萄糖为底物进行乙醇发酵。对不同底物浓度[5%,7.5%。10%(W/V)]、不同温度(25℃,30℃,35℃)条件下,游离细胞和固定化细胞乙醇发酵的特性进行研究。实验结果表明。葡萄糖浓度为5%。25℃时可达到最大的乙醇产率0.50g乙醇/g葡萄糖。以海藻酸钙为包埋介质,对Zymomonas mobilis进行固定化。在10%葡萄糖培养基中多批次半连续发酵,可在8h内使乙醇产率系数达到0.50。短的发酵周期和高的乙醇产率为后续的葡萄糖和木糖两步乙醇发酵提供理想的实验数据。 相似文献
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以水稻脆性秸秆为原料进行了发酵产乙醇的研究。用水稻脆性秸秆比用作对照的普通秸秆的半纤维素和木质素含量分别高17%和5%,纤维素含量低15%。采用浓度为2%(w/v)的硫酸进行秸秆预处理后,脆性秸秆稀酸水解液中葡萄糖含量为普通秸秆的1.38倍;每克脆性秸秆产生的木糖和阿拉伯糖比普通秸秆分别高出12.0 mg和3.9 mg;两种秸秆酸水解液中副产物乙酸、糠醛和5-羟甲基糠醛的浓度差异不显著。经过纤维素酶进一步处理后,每克脆性秸秆得到的总还原糖量为(541.2±8.0)mg,比普通秸秆高出41.9 mg。Escherichia coli SZ470利用酸预处理且酶促糖化的两种秸秆发酵72 h后,脆性秸秆发酵的乙醇产量可达(10.9±0.4)g/L,为普通秸秆的1.1倍。 相似文献
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木质纤维素稀酸水解液乙醇发酵的新方法 总被引:7,自引:0,他引:7
为了降低木质纤维素水解液发酵抑制剂对乙醇发酵的负影响,采用混合菌种对木质纤维素稀酸水解液乙醇发酵方式进行了研究。对批式发酵、补料批式发酵和间隔补料批式发酵3种发酵方式进行了比较。实验结果表明,间隔补料批式发酵可以有效地减弱水解液中抑制因子对菌种的影响,乙醇产量明显高于其他两种发酵方式,利用酿酒酵母(Saccaromyces cerevisiae 2.535)和嗜鞣管囊酵母(Pachysolen tannophilis ATCC 32728)混合发酵,乙醇产量最终达到14.4g/L,乙醇产率(Yp/s)为0.47g/g,相当于最大理论产率的92.2%。利用酿酒酵母和重组大肠杆菌混合菌种发酵,乙醇产量达到了14.5g/L。对木质纤维素稀酸水解液采用间隔补料批式乙醇发酵方法,可进一步减少抑制剂对乙醇发酵的影响,使发酵顺利进行。 相似文献
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运动发酵单胞菌232B木薯快速乙醇发酵 总被引:1,自引:0,他引:1
以运动发酵单胞菌232B(Z.mobilis 232B)为菌种,木薯为底物进行同步糖化快速乙醇发酵的研究.首先采用Full Factorial设计和最速上升实验确定了培养基成分中的两个显著性因子及其最适浓度:酵母粉4.0g·kg-1,硫酸铵0.8g·kg-1.在最适合的培养基条件下,对木薯料水比和糖化酶用量进行了优化,得到Z.mobilis232B木薯乙醇发酵最佳料水比为1:3,糖化酶浓度为4AGU·g-1淀粉,乙醇发酵4.915g·(kg·h)-1.利用高效液相色谱对发酵液中残糖进行了分析,证明葡萄糖、果糖等单糖已完全被菌体利用,剩余糖多为二糖、三糖等不可发酵的低聚糖. 相似文献
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《可再生能源》2013,(5):84-89
禾本科狗尾草属植物——狗牙根,纤维素含量非常丰富,纤维素经过稀酸、纤维素酶和木聚糖酶处理后,接种嗜鞣管囊酵母发酵可得到生物乙醇。试验以乙醇得率为指标,研究了葡萄糖、酵母膏、蛋白胨、接种量、温度、时间、pH等因素对乙醇得率的影响,通过正交试验,得到最佳的试验组合,最后用狗牙根糖化液代替葡萄糖进行发酵,生产制备生物乙醇。结果表明,在以葡萄糖为原料的乙醇生产过程中的最佳条件是:100 mL的培养基中,葡萄糖20 g、酵母膏1.5 g、蛋白胨0.5 g、接种量13 mL、温度30℃、时间60 h、pH5.5、硫酸铵1 g、磷酸二氢钾0.2 g、硫酸镁0.1 g,乙醇的最高产率为43.35%;狗牙根糖化液最终乙醇得率为7.04%。 相似文献
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Ethanol production from Canna edulis Ker was successfully carried out by solid state simultaneous saccharification and fermentation. The enzymatic hydrolysis conditions of C. edulis were optimized by Plackett–Burman design. The effect of inert carrier (corncob and rice bran) on ethanol fermentation and the kinetics of solid state simultaneous saccharification and fermentation was investigated. It was found that C. edulis was an alternative substrate for ethanol production, 10.1% (v/v) of ethanol concentration can attained when 40 g corncob and 10 g rice bran per 100 g C. edulis powder were added for ethanol fermentation. No shortage of fermentable sugars was observed during solid state simultaneous saccharification and fermentation. There was no wastewater produced in the process of ethanol production from C. edulis with solid state simultaneous saccharification and fermentation and the ethanol yield of more than 0.28 tonne per one tonne feedstock was achieved. This is first report for ethanol production from C. edulis powder. 相似文献
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《International Journal of Hydrogen Energy》2019,44(34):18785-18791
As a renewable energy source bio-hydrogen production from lignocellulosic wastes is a promising approach which can produce clean fuel with no CO2 emissions. Utilization of agro-industrial residues in solid state fermentation (SSF) is offering a solution to solid wastes disposal and providing an economical process of value-added products such as hydrogen.In this study three different particle size of rice husk (<2000 μm, <300 μm, <74 μm) was subjected to batch SSF with a Clostridium termitidis: Clostridium intestinale ratio of 5:1. C. termitidis is a cellulolytic microorganism that has the ability to hydrolyze cellulosic substances and C. intestinale is able to grow on glucose having a potential of enhancing hydrogen production when used in the co-culture. 5 g dw rice husk with 75% humidity was used as substrate in SSF under mesophilic conditions. The highest HF Volume (29.26 mL) and the highest yield (5.9 mL H2 g−1 substrate) were obtained with the smallest particle size (<74 μm). The main metabolites obtained from the fermentation media were acetic, butyric, propionic and lactic acids. The second best production yield (3.99 mL H2 g−1 substrate) was obtained with the middle particle size (<300 μm) rice husk with a HF of 19.71 mL. 相似文献
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微波预处理稻壳对纤维素酶固态发酵的影响 总被引:8,自引:0,他引:8
以稻壳为原料,通过微波预处理后用于固态发酵生产纤维素酶,研究了微波处理对后续发酵过程的影响。采用正交试验与单因素试验确定了微波处理的条件,并分析了微波功率与处理时间对发酵过程中纤维素酶活性及戊糖、还原糖含量的影响。试验结果表明,用功率为300W的微波处理稻壳7min后进行发酵,可以得到最高的纤维素酶酶活,其中滤纸酶活(干基质)可达7.09 IU/g,CMC酶活(干基质)可达87.24 IU/g,分别比未经处理的稻壳提高了21%和15%。若以单位能耗产生的酶活增加量计算,微波处理稻壳5min后发酵,可以得到最高的酶活性增加量。 相似文献
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S. S. Yang 《Renewable Energy》1996,9(1-4)
Cellulosic waste, corncob, was used as a substrate in the production of oxytetracycline by Streptomyces rimosus TM-55 in solid state fermentation. Oxytetracycline was detected on the fourth day, and reached its maximum on the eighth day. During cultivation, the moisture content of substrate increased as incubation being, and pH value increased slightly. Optimal conditions for oxytetracycline production were an initial pH of 5.2 to 6.3, an initial moisture content of 64 to 67%, supplemented with 20% (w/w) rice bran or 1.5 to 2.5% (NH4)2SO4 as the sole nitrogen source, 1.0% CaCO3, 2% MgSO4 7H2O, 0.5% KH2PO4, and 0.6 to 0.8% aspartic acid or lysine, with incubation for 8 days at 25 to 30°C. Each gram of substrate produced 10 to 11 mg of oxytetracycline. 相似文献
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Serpil Ozmihci 《International Journal of Hydrogen Energy》2017,42(37):23494-23499
Ground wheat (21 g) was subjected to batch solid state dark fermentation for bio-hydrogen production. Clostridium acetobutylicum (B-527) was used as the culture of dark fermentation bacteria at mesophilic conditions. Effects of moisture content on the rate and yield of bio-hydrogen formation were investigated. The highest CHF (1222 ml), hydrogen yield (63 ml H2 g?1 starch), formation rate (10.64 ml H2 g?1 starch h?1) and specific hydrogen formation rate (0.28 ml H2 g?1 biomass h?1) were obtained with a moisture content of 80%. Nearly complete starch hydrolysis and glucose fermentation were achieved with more than 80% moisture content and the highest substrate conversion rate (21.9 mg L?1 h?1) was obtained with 90% moisture content at batch solid state fermentation producing volatile fatty acids (VFA) and H2. 相似文献
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文章研究了Saccharomyces cerevisiae BY4742以葡萄糖为底物的发酵动力学。根据最优化影响因素实验的结果,利用Logistic方程、Leudeking-Piret方程和类Luedeking-Piret方程,分别建立了酵母乙醇发酵的菌体生长模型、产物形成模型以及底物消耗模型,利用软件拟合并得到模型的参数估值。结果表明,乙醇的合成与酵母菌的生长速率及菌体积累量均有关,根据细胞生长速率与产物形成速率是否偶联进行动力学分类,其属于部分偶联型。底物消耗模型和产物形成模型拟合度R2分别达到了0.983与0.900,可用于描述利用Saccharomyces cerevisiae BY4742菌株的葡萄糖发酵制乙醇过程。 相似文献
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《Applied Thermal Engineering》2000,20(6):529-543
The ethanol fermentation process using molasses as the feedstock has been studied. The process alternatives, compared to the original fermentation process described in the literature, have been modeled using single and double distillation columns. Short-cut and rigorous models for the distillation column were compared and their influence on the process economics indicate the rigorous model to be more exact, the short-cut model to be faster and more convenient for comparative analysis of finding the optimal process structure. The process with the single distillation column was shown to be the optimal variant requiring the lowest equipment and utilities cost. Estimated net present worth value for the single column was 29.6 MUSD and for the double columns 27.1 MUSD. A heat pump use was found to be a possible option for heat integration. The span of temperatures in distillation columns was confirmed to be the decisive factor for the economy of heat pump use. The pay back time was more than 5 years. Thermal integration reduced the total annual costs by 27% as compared to the basic process scheme. 相似文献