Zhai Lili, Manglekar Rupali Rahul, Geng Anli
School of Life Sciences and Chemical Technology, Ngee Ann Polytechnic, Singapore, Singapore.
Biotechnol Appl Biochem. 2020 Sep;67(5):714-722. doi: 10.1002/bab.1816. Epub 2019 Sep 16.
Oil palm empty fruit bunch (OPEFB) is a lignocellulosic biomass generated in palm oil mills. It is a sustainable resource for fuels and chemicals. In this study, OPEFB was converted to ethanol by an integrative OPEFB conversion process including dilute alkaline pretreatment, cellulolytic enzyme production, separate OPEFB hydrolysis, and cofermentation using a hybrid xylose-fermenting yeast. OPEFB was pretreated using 1% (w/v) NaOH solution followed by 1% (v/v) H O . Further, cellulolytic enzymes were produced by submerged fermentation using Trichoderma reesei Rut C30 and used for OPEFB hydrolysis. The filter paper cellulase activity of the crude cellulolytic enzymes was 15.1 IU/mL, which was higher than those obtained by reported Trichoderma strains under laboratory conditions. Glucose and xylose yields reached 66.9% and 74.2%, respectively, at 30 filter paper unit (FPU)/g-biomass enzyme dosage and 10% (w/v) biomass loading. The hybrid yeast strain ScF2 was previously constructed through recursive genome shuffling of Pichia stipitis and Saccharomyces cerevisiae and was used in OPEFB hydrolysate fermentation. About 16.9 g/L ethanol was produced with an ethanol yield of 0.34 g/g sugars, which was 67% of theoretical ethanol yield.
油棕空果串（OPEFB）是棕榈油厂产生的木质纤维素生物质。它是一种用于生产燃料和化学品的可持续资源。在本研究中，通过一个综合的OPEFB转化过程将OPEFB转化为乙醇，该过程包括稀碱预处理、纤维素酶生产、OPEFB单独水解以及使用混合木糖发酵酵母进行共发酵。使用1%（w/v）的NaOH溶液对OPEFB进行预处理，随后用1%（v/v）的H₂O₂处理。此外，使用里氏木霉Rut C30通过深层发酵生产纤维素酶，并将其用于OPEFB水解。粗纤维素酶的滤纸纤维素酶活性为15.1 IU/mL，高于在实验室条件下报道的里氏木霉菌株所获得的活性。在30滤纸单位（FPU）/g生物质酶用量和10%（w/v）生物质负载量的条件下，葡萄糖和木糖产率分别达到66.9%和74.2%。杂交酵母菌株ScF2先前通过树干毕赤酵母和酿酒酵母的递归基因组改组构建而成，并用于OPEFB水解产物发酵。产生了约16.9 g/L的乙醇，乙醇产率为0.34 g/g糖，为理论乙醇产率的67%。
