Abstract: The aims of this research were to isolate a Colletotrichum lini strain with higher DHEA tolerance and conversion efficiency. We utilized C. lini ST as the original strain and investigated the best conditions of protoplast release and regeneration for strain ST. Then the protoplasts of C. lini ST were treated by plasma irradiation and a positive mutant strain ST-0317 with high DHEA concentration tolerance and good genetic stability was obtained. At DHEA concentration of 10g/L，the 7α，15α-diOH-DHEA molar yield of ST-0317 was increased to 36.9%，with an improvement of 50% compared with the original strain. These results were beneficial for producing 7α，15α-diOH-DHEA through this productive mutant.

Key words: Colletotrichum lini, protoplasts, dehydroepiandrosterone, 7-alpha-15-alpha-double hydroxy dehydroepiandrosterone, mutation

摘要： 采用原生质体诱变技术选育出一株耐高浓度底物去氢表雄酮（DHEA）的高产亚麻刺盘孢菌株（Colletotrichum lini） ST-0317，并研究了其转化特性。以C. lini ST为出发菌株，考察了其原生质体制备与再生的最适条件，随后对其原生质体进行等离子诱变，最终选育得到优势突变株ST-0317。该菌株在底物耐受性提高的同时也具有良好的遗传稳定性，在DHEA投料浓度高达10g/L的条件下，产物7α,15α-diOH-DHEA摩尔得率可达36.9%，比出发菌株提高了50%。

关键词: 亚麻刺盘孢, 原生质体, 去氢表雄酮, 7α, 15α-diOH-DHEA, 等离子诱变