嗜热毁丝霉木糖代谢调控机制研究
Research on Regulation Mechanism of Xylose Metabolism in Myceliophthora thermophila
陈美欣 1顾淑莹 2刘佳 2刘浩 3李金根 2田朝光2
作者信息
- 1. 天津科技大学生物工程学院,天津 300457;中国科学院天津工业生物技术研究所,天津 300308
- 2. 中国科学院天津工业生物技术研究所,天津 300308
- 3. 天津科技大学生物工程学院,天津 300457
- 折叠
摘要
为提高发酵菌株的木糖利用速率,以嗜热毁丝霉为体系,利用遗传学手段及转录组学技术,探究丝状真菌嗜热毁丝霉木糖代谢的调控机制.结果表明,在嗜热毁丝霉中,转录因子XlnR能够正向调控木糖代谢和转运以及半纤维酶的表达,是木糖条件下孢子萌发的必需因子.在木糖条件下,突变体ΔxlnR孢子丧失了萌发的能力,并且菌丝木糖利用速率显著降低,而过表达xlnR 使得木糖利用速率提升14.2%.转录组数据表明,敲除xlnR导致木聚糖水解酶基因、木糖转运蛋白及代谢相关基因的转录水平显著降低.全局调控因子Cre-1是木糖及葡萄糖代谢的抑制因子,敲除cre-1后显著提升嗜热毁丝霉木糖和葡萄糖利用速率;同时,Cre-1可直接抑制xlnR及自身的表达.通过过表达木糖代谢激活因子XlnR编码基因xlnR,同时敲除抑制因子Cre-1编码基因cre-1,嗜热毁丝霉木糖利用速率提高100%.以上研究结果为生物质高效利用底盘细胞的创建提供了良好的出发菌株.
Abstract
In order to improve xylose utilization efficiency of fermentation strains,the regulation mechanism of xylose metabolism in filamentous fungi Myceliophthora thermophila was investigated using genetic methods and transcriptomic techniques.The results showed that the transcription factor XlnR could positively regulate xylose metabolism and transport,as well as hemicellulase gene expression in M.thermophila,and was required for conidia germination under xylose conditions.Under xylose condition,the conidia of mutant ΔxlnR lost the ability to germinate,and the xylose utilization efficiency of mycelia was significantly decreased,while the xylose utilization efficiency was increased by 14.2%due to xlnR overexpression.Transcriptomic analysis showed that knockout of xlnR resulted in lower transcription levels of the genes involved in xylanolytic enzymes,xylose transporter,and xylose catabolic pathway.The global regulatory factor Cre-1 was an inhibitor of xylose and glucose metabolism.Disruption of cre-1 could significantly improve the utilization efficiency of xylose and glucose in M.thermophila.Meanwhile,the Cre-1 could directly inhibit the expression of xlnR and itself.The overexpression of xlnR and knockout of cre-1 made the xylose metabolic utilization efficiency increased by 100%.Above results provided a good starting strain for the establishment of the cell chassis for the efficient utilization of biomass.
关键词
嗜热毁丝霉/木糖代谢/转录调控/Cre-1/XlnRKey words
Myceliophthora thermophila/xylose metabolism/transcription regulation/Cre-1/XlnR引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
万方数据