Thermoascus aurantiacus is a thermophilic fungus that belongs to the ascomycetous class and has attracted increasing interest for its ability to produce thermostable cellulolytic enzymes and growth at elevated temperatures. However, studies on this organism have been limited because of the lack of a genetic manipulation system. Here, we developed a polyethylene glycol (PEG)-mediated transformation system for T. aurantiacus based on an orotidine-5'-monophosphate decarboxylase (pyrG)-deficient mutant, with this method achieving a transformation efficiency of 33 ± 3 transformants per microgram of DNA. Intracellular or secretory expression of heterologous proteins, including green fluorescent protein, β-galactosidase and α-amylase, in T. aurantiacus was successful under the inducible endogenous cellobiohydrolase and endoglucanase gene promoter or the constitutive heterologous pyruvate decarboxylase and enolase gene promoter from Trichoderma reesei. To the best of our knowledge, this is the first report on PEG-mediated transformation of T. aurantiacus, which sets the foundation for strain improvement for biotechnological applications and functional genomic studies.

Thermoascus aurantiacus是一种嗜热真菌，属于子囊菌纲，因其产生耐热纤维素分解酶和在高温下生长的能力而受到越来越多的关注。然而，由于缺乏基因操纵系统，对这种生物的研究受到限制。在这里，我们开发了一种聚乙二醇 (PEG) 介导的T. aurantiacus转化系统，该系统基于乳清蛋白-5'-单磷酸脱羧酶 (pyrG) 缺陷突变体，该方法实现了每微克 33 ± 3 个转化子的转化效率脱氧核糖核酸。异源蛋白的细胞内或分泌表达，包括绿色荧光蛋白、β-半乳糖苷酶和α-淀粉酶，在T. aurantiacus在诱导型内源性纤维二糖水解酶和内切葡聚糖酶基因启动子或来自里氏木霉的组成型异源丙酮酸脱羧酶和烯醇化酶基因启动子下获得成功。据我们所知，这是第一份关于 PEG 介导的橙黄色葡萄球菌转化的报告，它为生物技术应用和功能基因组研究的菌株改良奠定了基础。