Jeonbuk Branch Institute, Korea Research Institute of Bioscience and Biotechnology, 181 Ipsin-gil, Jeongeup 56212, Republic of Korea.
Biomed Res Int. 2018 Sep 5;2018:5272935. doi: 10.1155/2018/5272935. eCollection 2018.
Empty palm fruit bunch fiber (EPFBF) is a renewable resource in oil palm plantations that can be used for lignocellulosic bioethanol production. To enhance ethanol productivity with high-lignin-content EPFBF, the biomass was prepared with an alkali-thermal pretreatment (sodium hydroxide, 121°C, 60 min). The delignification yield was 55.4-56.9%, in proportion to the amount of sodium hydroxide, from 0.5 to 2.0 M. The lignin and hemicellulose contents of EPFBF were reduced by the pretreatment process, whereas the proportion of cellulose was increased. During enzymatic saccharification using Celluclast 1.5L and Novozyme 188 enzyme cocktails, about 62% of glucan was converted to a fermentable sugar. In simultaneous saccharification and fermentation, comparison among three ethanologenic yeast strains showed W303-1A to be a candidate for maximum ethanol yield. In a batch fermentation with alkali-pretreated EPFBF hydrolysate, 21 g/L ethanol was obtained within 28 h, for a production yield of 0.102 g ethanol/g dry EPFBF or 0.458 g ethanol/g glucose. Moreover, a fed-batch fermentation produced 33.8±0.5 g/L ethanol with 1.57 g/L/h productivity in 20 h. These results show that the combination of alkaline pretreatment and biomass hydrolysate is useful for enhancing bioethanol productivity using delignified EPFBF.
空果串纤维（EPFBF）是油棕种植园中一种可再生资源，可用于木质纤维素生物乙醇生产。为了提高高木质素含量的 EPFBF 的乙醇生产力，采用碱-热预处理（氢氧化钠，121°C，60 分钟）对生物质进行预处理。脱木质素率与氢氧化钠用量成正比，从 0.5 至 2.0M 时，脱木质素率为 55.4-56.9%。预处理过程降低了 EPFBF 中的木质素和半纤维素含量，而纤维素的比例增加。使用 Celluclast 1.5L 和 Novozyme 188 酶混合物进行酶解糖化时，约 62%的葡聚糖转化为可发酵糖。在同步糖化发酵中，对三种产乙醇酵母菌株的比较表明，W303-1A 是最大乙醇产量的候选菌株。在碱性预处理 EPFBF 水解物的分批发酵中，28 小时内获得了 21g/L 的乙醇，产率为 0.102g 乙醇/g 干 EPFBF 或 0.458g 乙醇/g 葡萄糖。此外，在 20 小时的 fed-batch 发酵中，以 1.57g/L/h 的生产率产生了 33.8±0.5g/L 的乙醇。这些结果表明，碱性预处理和生物质水解物的组合可用于提高经脱木质素的 EPFBF 的生物乙醇生产力。
