Co-fermentation of a mixture of glucose and xylose to ethanol by Zymomonas mobilis and Pachysolen tannophilus
Co-fermentation of a mixture of glucose and xylose to ethanol by Zymomonas mobilis and Pachysolen tannophilus
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DOI：
10.1007/s11274-007-9613-2
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发表时间：
2008-07-01
影响因子：
4.1
通讯作者：
Peiris, Paul
中科院分区：
文献类型：
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作者：
Fu, Nan;Peiris, Paul
本研究旨在利用葡萄糖-木糖混合物（模拟甘蔗渣水解物）与活动单胞菌和嗜坦肿梭菌共发酵，最大限度地提高乙醇产量。在50 g葡萄糖/l条件下，其体积乙醇产率为2.87 g/l/h，乙醇产率为0.50 g/g葡萄糖，为理论产率的98%。在50 g木糖/l培养基上培养时，P. tannophilus的体积乙醇产量为0.10 g/l/h，乙醇产量为0.15 g/g木糖，为理论产量的29%。通过优化糖液（葡萄糖60 g/ l，木糖40 g/ l）共发酵，乙醇总产率为0.33 g/g，为理论产率的65%。共发酵使木糖乙醇产率提高到0.17 g/g。葡萄糖和木糖被完全利用，发酵结束时培养基中未检测到残糖。培养基的pH值是发酵状态的一个很好的指标。最适条件为：温度30℃，先接种运动弧菌，不曝气孵育，利用葡萄糖后灭活细菌，再接种嗜坦弧菌，限制曝气孵育。
This research was designed to maximize ethanol production from a glucose-xylose sugar mixture (simulating a sugar cane bagasse hydrolysate) by co-fermentation with Zymomonas mobilis and Pachysolen tannophilus. The volumetric ethanol productivity of Z. mobilis with 50 g glucose/l was 2.87 g/l/h, giving an ethanol yield of 0.50 g/g glucose, which is 98% of the theoretical. P. tannophilus when cultured on 50 g xylose/l gave a volumetric ethanol productivity of 0.10 g/l/h with an ethanol yield of 0.15 g/g xylose, which is 29% of the theoretical. On optimization of the co-fermentation with the sugar mixture (60 g glucose/l and 40 g xylose/l) a total ethanol yield of 0.33 g/g sugar mixture, which is 65% of the theoretical yield, was obtained. The co-fermentation increased the ethanol yield from xylose to 0.17 g/g. Glucose and xylose were completely utilized and no residual sugar was detected in the medium at the end of the fermentation. The pH of the medium was found to be a good indicator of the fermentation status. The optimum conditions were a temperature of 30 degrees C, initial inoculation with Z. mobilis and incubation with no aeration, inactivation of bacterium after the utilization of glucose, followed by inoculation with P. tannophilus and incubation with limited aeration.