Sequential fed batch extractive fermentation for enhanced bioethanol production using recycled Spathaspora passalidarum and mixed sugar composition

Farias D.; Maugeri-Filho F.

摘要

The simultaneous ethanol production and removal during sequential cell recycle fed batch fermentation provides a complementary route to produce this biofuel from sugar mixtures, which may greatly improve yields and productivity from lignocellulosic hydrolysates. Spathaspora passalidarum is a wild-type strain able to naturally convert glucose, fructose, xylose and arabinose into ethanol. Therefore, the present work has focused on 2G bioethanol production by S. passalidarum aiming at the consumption of all sugars released after pre-treatment and enzymatic hydrolysis of sugarcane bagasse in a single fermentation step. The fermentation strategy with sequential cell recycle, fed-batch mode and ethanol removal in situ was performed on a hemicellulosic hydrolysate medium supplemented with molasses. This strategy gave improved fermentation performance and enabled the co-fermention of all sugars under microaerobic conditions. The maximum ethanol yield and productivity was 0.482 g.g(-1) and 9.5 g.L-1.h(-1), respectively, showing a process efficiency of 94.3%. The selective ethanol removal enables the operation of the bioreactor at low levels of ethanol (20-30 g.L-1), even with high sugar concentration inputs, accelerating the fermentation performance and avoiding inhibitory effects on yeast metabolism. Applying the cell recycle strategy, S. passalidarum was able to increase its robustness, as shown by a 10-fold increase in ethanol productivity, and it was also able to tolerate a high acetic acid concentration (4.5 g.L-1) during long-term fermentations. These results demonstrate that the bioprocess strategy has a strong potential to improve bioethanol production of rich mixed sugar from lignocellulosic hydrolysates in a single fermentation step.

机译：顺序细胞再循环分批发酵同时乙醇的生产和去除提供了一种互补的途径，以产生这种生物燃料的糖混合物，这可能大大提高木质纤维素水解产物的产率和生产率。 spathaspora passalidarum是一种野生型菌株，能够自然地将葡萄糖，果糖，木糖和阿拉伯糖转化为乙醇。因此，本作本作的重点是S. PassalidArum的2g生物乙醇生产，旨在在单一发酵步骤中甘蔗果糖的预处理和酶水解后释放的所有糖的消耗。用序列细胞再循环，进料批量和乙醇去除原位的发酵策略在补充有糖蜜的半纤维素水解介质上进行。该策略提高了发酵性能，使得在微生物条件下使所有糖的共发酵。最大乙醇产率和生产率分别为0.482g，效率为0.482g，9.5g1-1.h（-1），显示过程效率为94.3％。选择性乙醇去除使得能够在低水平的乙醇（20-30g1-1）下的生物反应器的操作，即使具有高糖浓度的输入，加速发酵性能并避免对酵母代谢的抑制作用。应用细胞再循环策略，S. PassalyArum能够增加其鲁棒性，如乙醇生产率的10倍，并且在长期期间也能够耐受高乙酸浓度（4.5GL-1）发酵。这些结果表明，生物过程策略具有改善从单一发酵步骤中的木质纤维素水解产物的生物乙醇生产富含混合糖的生物乙醇生产。

Sequential fed batch extractive fermentation for enhanced bioethanol production using recycled Spathaspora passalidarum and mixed sugar composition

摘要

著录项

相关主题

期刊订阅