Department of Bioenergy Science and Technology, Chonnam National University, Gwangju 500-757, Republic of Korea.
Department of Wood Science and Landscape Architecture, Chonnam National University, Gwangju 500-757, Republic of Korea.
Bioresour Technol. 2014 Feb;153:47-54. doi: 10.1016/j.biortech.2013.11.059. Epub 2013 Dec 1.
The microalga Chlorella vulgaris is a potential feedstock for bioenergy due to its rapid growth, carbon dioxide fixation efficiency, and high accumulation of lipids and carbohydrates. In particular, the carbohydrates in microalgae make them a candidate for bioethanol feedstock. In this study, nutrient stress cultivation was employed to enhance the carbohydrate content of C. vulgaris. Nitrogen limitation increased the carbohydrate content to 22.4% from the normal content of 16.0% on dry weight basis. In addition, several pretreatment methods and enzymes were investigated to increase saccharification yields. Bead-beating pretreatment increased hydrolysis by 25% compared with the processes lacking pretreatment. In the enzymatic hydrolysis process, the pectinase enzyme group was superior for releasing fermentable sugars from carbohydrates in microalgae. In particular, pectinase from Aspergillus aculeatus displayed a 79% saccharification yield after 72h at 50°C. Using continuous immobilized yeast fermentation, microalgal hydrolysate was converted into ethanol at a yield of 89%.
小球藻是一种有潜力的生物能源原料，因为它具有快速生长、二氧化碳固定效率高和高积累脂质和碳水化合物的特点。特别是，微藻中的碳水化合物使它们成为生物乙醇原料的候选物。在这项研究中，采用营养胁迫培养来提高小球藻的碳水化合物含量。氮限制将碳水化合物的含量从干重基础上的正常含量 16.0%提高到 22.4%。此外，还研究了几种预处理方法和酶来提高糖化产率。珠磨预处理比缺乏预处理的过程提高了 25%的水解率。在酶解过程中，果胶酶酶组在从微藻碳水化合物中释放可发酵糖方面表现优异。特别是，来自 Aspergillus aculeatus 的果胶酶在 50°C 下 72 小时后显示出 79%的糖化产率。使用连续固定化酵母发酵，微藻水解物转化为乙醇的产率为 89%。
