Jeonbuk Branch Institute, Korea Research Institute of Bioscience and Biotechnology, 181 Ipsin-gil, Jeongeup 580-185, South Korea.
Appl Biochem Biotechnol. 2013 Mar;169(5):1531-45. doi: 10.1007/s12010-013-0094-5. Epub 2013 Jan 16.
Jerusalem artichoke is a low-requirement sugar crop containing cellulose and hemicellulose in the stalk and a high content of inulin in the tuber. However, the lignocellulosic component in Jerusalem artichoke stalk reduces the fermentability of the whole plant for efficient bioethanol production. In this study, Jerusalem artichoke stalk was pretreated sequentially with dilute acid and alkali, and then hydrolyzed enzymatically. During enzymatic hydrolysis, approximately 88 % of the glucan and xylan were converted to glucose and xylose, respectively. Batch and fed-batch simultaneous saccharification and fermentation of both pretreated stalk and tuber by Kluyveromyces marxianus CBS1555 were effectively performed, yielding 29.1 and 70.2 g/L ethanol, respectively. In fed-batch fermentation, ethanol productivity was 0.255 g ethanol per gram of dry Jerusalem artichoke biomass, or 0.361 g ethanol per gram of glucose, with a 0.924 g/L/h ethanol productivity. These results show that combining the tuber and the stalk hydrolysate is a useful strategy for whole biomass utilization in effective bioethanol fermentation from Jerusalem artichoke.
洋姜是一种低要求的糖料作物，其茎秆中含有纤维素和半纤维素，块茎中含有较高的菊粉。然而，洋姜茎秆中的木质纤维素成分降低了整株植物的发酵性能，不利于高效生产生物乙醇。在本研究中，洋姜茎秆依次经过稀酸和稀碱预处理，然后进行酶水解。在酶水解过程中，大约 88%的葡聚糖和木聚糖分别转化为葡萄糖和木糖。通过 Kluyveromyces marxianus CBS1555 对预处理的茎秆和块茎进行分批和流加批式同步糖化发酵，分别可得到 29.1 和 70.2 g/L 的乙醇。在流加批式发酵中，乙醇得率为 0.255 g 乙醇/克干洋姜生物质，或 0.361 g 乙醇/克葡萄糖，乙醇生产率为 0.924 g/L/h。这些结果表明，将块茎和茎秆水解液结合起来是一种有效的策略，可以充分利用整株生物质，从洋姜中有效发酵生产生物乙醇。
