Cellulase Recycling after High-Solids Simultaneous Saccharification and Fermentation of Combined Pretreated Corncob
Cellulase Recycling after High-Solids Simultaneous Saccharification and Fermentation of Combined Pretreated Corncob
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DOI：
10.3389/fenrg.2014.00024
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发表时间：
2014-06
影响因子：
3.4
通讯作者：
Ruoyu Du;R. Su;Mingjia Zhang;W. Qi;Zhimin He
中科院分区：
文献类型：
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作者：
Ruoyu Du;R. Su;Mingjia Zhang;W. Qi;Zhimin He
尽管第二代生物乙醇具有良好的前景，但其最终商业化必须克服酶假设所带来的主要成本障碍。为解决这一问题，本研究通过工艺集成实现了高浓度酒精发酵和纤维素酶的多轮循环利用。通过对纤维素酶吸附动力学的研究，确定了再吸附的最佳时间和温度。葡萄糖和纤维二糖均抑制纤维素酶的吸附。乙醇发酵96 h后，40%的纤维素酶保留在发酵液中，其中62.5%的纤维素酶可回收利用，并在新鲜底物再吸附90 min。pH 5.0、15wt%的干物质负载、45 FPU/g葡聚糖的纤维素酶负载、两个发酵和再吸附循环可以产生两倍增加的乙醇产量，并且将酶成本降低超过50%。每个循环中的乙醇浓度可以达到大于40 g/L的水平。
Despite the advantageous prospect of second-generation bioethanol, its final commercialization must overcome the primary cost impediment due to enzyme assumption. To solve this problem, this work achieves high-concentration ethanol fermentation and multi-round cellulase recycling through process integration. The optimal time and temperature of the re-adsorption process were determined by monitoring the adsorption kinetics of cellulases. Both glucose and cellobiose inhibited cellulase adsorption. After 96 h of ethanol fermentation, 40% of the initial cellulase remained in the broth, from which 62.5% of the cellulase can be recycled and reused in fresh substrate re-adsorption for 90 min. Under optimum conditions, i.e., pH 5.0, dry matter loading of 15 wt%, cellulase loading of 45 FPU/g glucan, two cycles of fermentation and re-adsorption can yield two-fold increased ethanol outputs and reduce enzyme costs by over 50%. The ethanol concentration in each cycle can be achieved at levels greater than 40 g/L.