构建微生物细胞工厂利用木糖合成高值化学品

Construction of microbial cell factories for synthesizing value-added chemicals with xylose

摘要:

木质纤维素是地球上最丰富的可再生资源。以木质纤维素为原料利用微生物细胞工厂合成高附加值化学品是实现绿色生物制造的关键。木糖是木质纤维素中含量仅次于葡萄糖的第二大可发酵糖，因此构建可高效代谢木糖的微生物细胞工厂对于实现木质纤维素的全利用具有重要意义。然而与葡萄糖相比，大多数微生物代谢木糖的效率较低，限制了木糖的应用。近年来，微生物代谢机制的深入理解和合成生物学技术的不断进步极大地提高了微生物代谢木糖的效率，拓展了木糖衍生产品的种类。本文综述了自然界存在的几条木糖代谢途径及其衍生的相关产品，总结了构建木糖和葡萄糖共利用菌株的策略，概括了利用木质纤维素水解产物合成目标产品的研究进展，并对相关技术瓶颈和未来发展方向进行了讨论与展望。

Abstract:

Lignocellulose is the most abundant renewable resource on earth. Constructing microbial cell factories for synthesizing value-added chemicals with lignocellulose is the key to realize green biomanufacturing. Xylose is the second most fermentable sugar in lignocellulose after glucose. Building microbial cell factories that can efficiently metabolize xylose is of great significance to achieve full utilization of lignocellulose. However, the lower metabolism efficiency of xylose than that of glucose in most microorganisms limits the application of xylose. In recent years, the deepening understanding of microbial metabolic mechanisms and the continuous advancement of synthetic biology have greatly improved the efficiency of microbial metabolism of xylose and expanded the spectrum of xylose-derived products. This article introduces several xylose metabolic pathways that exist in the nature and the derived products, summarizes the strategies for constructing recombinant strains that can co-utilize xylose and glucose, and reviews the research progress in the application of lignocellulose hydrolysates in the synthesis of target products. Finally, this article discusses the current technical bottlenecks and prospects the future development directions in this field.