Investigating the Molecular Crosstalk of Cellulose and Hemicellulose Perception in Filamentous Fungi

研究丝状真菌中纤维素和半纤维素感知的分子串扰

• 批准号: 391588914
• 负责人: Professor Dr. J. Philipp Benz
• 金额: --
• 依托单位: National Natural Science Foundation of China
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/391588914?language=en
• 关键词: Investigating; Molecular; Crosstalk; Cellulose; Hemicellulose

Due to their role in biomass mineralization, fungi are indispensable for the global carbon cycle. In addition, filamentous fungi are of great economic importance as source of enzymes for the biorefinery. The production of plant cell wall degrading enzymes by fungi is finely tuned to the composition of the biomass. The basis for this are molecular signaling cascades leading to the perception of sugars liberated from the polysaccharides. However, the signaling pathways are still largely a black box to us, hampering the industrial strain improvement for enzyme, cellulosic fuel and chemical production by rational design. Biomass decomposition for biorefinery will highly benefit from an increased understanding of how fungi perceive and integrate the signals coming from the substrate and fine-tune their secreted enzymes to exactly fit the composition of the biomass at hand. In our attempts to elucidate plant cell wall perception in the filamentous Ascomycete Neurospora crassa, we have obtained evidence that not all sugars are perceived independently, but that some pathways overlap such that a reciprocal inhibition can occur, as is the case for cellulose and mannan signaling. Moreover, we found this crosstalk to be conserved in the industrially relevant species Trichoderma reesei and Myceliophthora thermophila. Since mannans are present in most lignocellulosic biomass and are very difficult to be selectively removed from cellulose and other hemicelluloses by chemical (pre-)treatments, the crosstalk has to be dealt with by other methods. A promising solution to this problem might be genetic engineering of the signaling pathways in the fungal production hosts. In the current application, we therefore propose a research program to elucidate the underlying mechanisms of this crosstalk in N. crassa, T. reesei and M. thermophila with the goal to relief them from this potential inhibition by genetic engineering and achieve unrestrained cellulase production. Moreover, the elucidation of the molecular mechanisms controlling these events will also strongly fasten future industrial fungal strain engineering efforts for the biorefinery.

由于它们在生物质矿化中的作用，真菌是全球碳循环不可或缺的。此外，丝状真菌作为生物精炼的酶来源具有重要的经济意义。真菌产生的植物细胞壁降解酶与生物质的组成密切相关。其基础是导致从多糖中释放的糖的感知的分子信号级联。然而，信号通路对我们来说仍然是一个黑匣子，阻碍了通过合理的设计来改进酶，纤维素燃料和化学品生产的工业菌株。生物炼制的生物质分解将极大地受益于对真菌如何感知和整合来自底物的信号的更多理解，并微调其分泌的酶以精确地适应手头的生物质的组成。在我们试图阐明丝状子囊菌粗糙脉孢菌的植物细胞壁感知，我们已经获得的证据表明，不是所有的糖被独立地感知，但有些途径重叠，这样可以发生相互抑制，纤维素和甘露聚糖信号的情况下。此外，我们发现这种串扰是保守的工业相关物种里氏木霉和嗜热毁丝霉。由于甘露聚糖存在于大多数木质纤维素生物质中，并且很难通过化学（预）处理从纤维素和其他半纤维素中选择性去除，因此必须通过其他方法处理串扰。一个有前途的解决方案，这个问题可能是在真菌生产宿主的信号通路的基因工程。因此，在当前的应用中，我们提出了一个研究计划，以阐明这种串扰在N。crassa，T. reesei和M.目的是通过基因工程将它们从这种潜在的抑制中释放出来，并实现不受限制的纤维素酶生产。此外，阐明控制这些事件的分子机制也将大大加快未来的生物炼制工业真菌菌株工程的努力。