Kadoya Ryosuke, Matsumoto Ken'ichiro, Takisawa Kenji, Ooi Toshihiko, Taguchi Seiichi
Department of Chemistry for Life Sciences and Agriculture, Faculty of Life Sciences, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya, Tokyo 156-8502, Japan.
Division of Applied Chemistry, Engineering, Graduate School of Engineering, Hokkaido University, N13-W8, Kita-ku, Sapporo 060-8628, Japan; CREST, JST, Sanbancho, Chiyoda-ku, Tokyo 102-0075, Japan.
J Biosci Bioeng. 2018 Apr;125(4):365-370. doi: 10.1016/j.jbiosc.2017.11.003. Epub 2018 Jan 10.
Lignocellulose-utilizing biorefinery is a promising strategy for the sustainable production of value-added products such as bio-based polymers. Simultaneous consumption of glucose and xylose in Escherichia coli was achieved by overexpression of the gene encoding Mlc, a multiple regulator of glucose and xylose uptake. This catabolite derepression gave the enhancement in the production of poly (15 mol% lactate-co-3-hydroxybutyrate), up to 65% from 50% (wild-type strain) in the cellular contents, of the Mlc-overexpressing strain of E. coli on a mixture of glucose and xylose as carbon sources. Microscopic analysis indicated that the Mlc-overexpressing strain showed the enlargement of cell volume in the presence and absence of polymer production, consequently making an expanded volumetric space available for enhanced polymer accumulation. The enhanced polymer production by the catabolite derepression was also reproducible using the biomass, Miscanthus×giganteus (hybrid Miscanthus), which was cultivated in the farm of Hokkaido University.
利用木质纤维素的生物精炼是可持续生产增值产品（如生物基聚合物）的一种有前景的策略。通过过表达编码Mlc（一种葡萄糖和木糖摄取的多重调节因子）的基因，实现了大肠杆菌对葡萄糖和木糖的同时消耗。这种分解代谢物阻遏解除使聚（15摩尔%乳酸-co-3-羟基丁酸酯）的产量提高，在以葡萄糖和木糖混合物为碳源时，大肠杆菌Mlc过表达菌株细胞内容物中的产量从50%（野生型菌株）提高到65%。显微镜分析表明，Mlc过表达菌株在有和没有聚合物产生的情况下都显示出细胞体积增大，从而为增强聚合物积累提供了更大的体积空间。使用在北海道大学农场种植的生物质芒草（杂交芒草），通过分解代谢物阻遏解除提高聚合物产量的方法也是可重复的。
