毛壳科真菌嗜热种的系统演化及其嗜热性分子基础研究

嗜热真菌是新型工业用热稳定酶储备库，具有催化反应高效、快速和污染风险低等突出优势。毛壳科是真菌界中嗜热种最丰富的科，但因判别嗜热种的标准不明确，它们在科内的起源和演化关系未知，严重阻碍了对其深入认识和利用。申请人前期已初步建立毛壳科现代分类系统主体框架。本项目拟在此基础上收集全球目标菌株，系统比较科内不同种的生长温度习性，科学划定嗜热种和有致病风险耐热种间界限；利用多基因序列和分子钟分析，确定各嗜热种的系统学位置、起源分化规律和各自的非嗜热近缘种；通过比较基因组学研究、转录组数据分析和分子生物学验证，揭示嗜热种与非嗜热近缘种在基因组、基因网络和关键基因结构上的差异及差异基因与嗜热性间相关性。研究结果将阐明毛壳科嗜热种的生物学本质和系统演化规律，揭示嗜热种的嗜热性及其催化酶热稳定性的分子机制，为系统发掘毛壳科嗜热种的热稳定酶和耐热元件在工业、生物技术与合成生物学等领域的应用潜力奠定科学基础。

Thermophilic fungi are a reservoir of novel thermostable enzymes for industrial use. The use of thermostable enzymes presents remarkable advantage in high efficiency, high speed of reaction and low risk of contamination. The family Chaetomiaceae is considered to contain the largest number of thermophilic species in the kingdom Fungi. But there is not a scientific standard for determining whether a fungus is thermophilic or not, also it remains unclear about the origin of the thermophiles and their phylogenetic relationships in the family, hampering us to deeply understand and apply those thermophilic ones. The applicant has established a mainframe of the modern classification system of Chaetomiaceae. After globally collecting the targeted thermophilic strains in this envisaged study, we will scientifically distinguish thermophilic and thermotolerant species on the basis of comparison of the growth adaptation of different species in the family to temperature; determine the phylogenetic placement of each of the thermophilic species in the family, clarify how they originate and evolve and which are their close relatives according to the multigene phylogenetic analysis and divergence time calibration using molecular clock methods; investigate the molecular foundation of the thermophilic character at both genome and gene levels by comparative genome analyses of the thermophilic species and their non-thermophilic close relatives together with transcriptome analyses and molecular biological verification. The results will reveal the biological nature of the thermophilc species in the family and their evolutionary history, and also give deep insight into the molecular mechanisms of both their thermophilic character and the thermostability of their enzymes. This study will provide a scientific basis for exploring and utilizing thermostable enzymes and thermotolerant elements from the Chaetomiaceae in the fields of industry, biotechnology and synthetic biology.