Tareen Afrasiab Khan, Punsuvon Vittaya, Sultan Imrana Niaz, Khan Muhammad Waseem, Parakulsuksatid Pramuk
Department of Biotechnology, Faculty of Agro-Industry, Kasetsart University, 50 Ngam Wong Wan Rd, Ladyao, Chatuchak, Bangkok 10900, Thailand.
Department of Chemistry, Faculty of Science, Kasetsart University, 50 Ngam Wong Wan Rd, Ladyao, Chatuchak, Bangkok 10900, Thailand.
ACS Omega. 2021 Sep 27;6(40):26119-26129. doi: 10.1021/acsomega.1c03111. eCollection 2021 Oct 12.
In the current study, alkaline hydrogen peroxide pretreated oil palm trunk fibers were subjected to ethanol production via simultaneous saccharification and fermentation (SSF). The effect of high substrate loading, enzyme and substrate feeding strategy, and influence of a pre-hydrolysis step in SSF was studied to scale up ethanol production. In the enzyme feeding strategy, the addition of an enzyme at the start of fed-batch SSF significantly ( < 0.05) increased ethanol concentration to 51.05 g/L, ethanol productivity ( ) to 0.61 g/L·h, and ethanol yield ( ) to 0.31 g/g, with a theoretical ethanol yield of 60.65%. Furthermore, the initial velocity of the enzyme ( ) in the first 8 h was 2.27 (g/h) with a glucose concentration of 18.17 g/L. On the other hand, the substrate feeding strategy and pre-hydrolysis simultaneous saccharification and fermentation (PSSF) process were studied in a 1 L fermenter. PSSF in fed batch with 10 and 20% (w/v) significantly improved enzyme hydrolysis, circumvent the problems of high viscosity, reduced overall fermentation time, and gave the highest ethanol concentration of 51.66 g/L, ethanol productivity ( ) of 0.72 g/L·h, ethanol yield ( ) of 0.31 g/g, and theoretical ethanol yield of 60.66%. In addition, PSSF with 10 and 20% significantly increased the initial velocity of the enzyme ( ) to 4.64 and 4.40 (g/h) and glucose concentration to 37.14 and 35.27 g/L, respectively. This result indicated that ethanol production by PSSF along with substrate feeding could enhance ethanol production efficiently.
在当前研究中，对经碱性过氧化氢预处理的油棕树干纤维进行了同步糖化发酵（SSF）以生产乙醇。研究了高底物负荷、酶和底物添加策略以及预水解步骤对SSF放大乙醇生产的影响。在酶添加策略中，在分批补料SSF开始时添加酶显著（<0.05）提高了乙醇浓度至51.05 g/L、乙醇生产率（）至0.61 g/L·h、乙醇产率（）至0.31 g/g，理论乙醇产率为60.65%。此外，在前8小时酶的初始速度（）为2.27（g/h），葡萄糖浓度为18.17 g/L。另一方面，在1 L发酵罐中研究了底物添加策略和预水解同步糖化发酵（PSSF）过程。10%和20%（w/v）分批补料的PSSF显著改善了酶水解，解决了高粘度问题，缩短了总发酵时间，乙醇浓度最高达到51.66 g/L、乙醇生产率（）为0.72 g/L·h、乙醇产率（）为0.31 g/g，理论乙醇产率为60.66%。此外，10%和20%的PSSF分别显著提高了酶的初始速度（）至4.64和4.40（g/h）以及葡萄糖浓度至37.14和35.27 g/L。该结果表明，PSSF结合底物添加可有效提高乙醇产量。
