Li Hui, Yin Siqi, Zhang Xiaomei, Zhang Xiaojuan, Li Heng, Shi Jinsong, Xu Zhenghong
School of Pharmaceutical Science, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.
Appl Biochem Biotechnol. 2016 Jan;178(1):91-100. doi: 10.1007/s12010-015-1860-3. Epub 2015 Oct 3.
7α,15α-diOH-DHEA is a key precursor of the novel oral contraceptive Yasmin. Colletotrichum lini could catalyze dehydroepiandrosterone (DHEA) at the 7α and 15α positions. In this work, C. lini resting cells were applied in the bioconversion of DHEA to 7α,15α-diOH-DHEA. In the presence of 2 % (w/v) Tween-80, the conversion efficiency of DHEA increased drastically. The DHEA conversion and the 7α,15α-diOH-DHEA yield increased by 34.6 and 87.0 %, respectively, at the DHEA concentration of 10 g/L. Furthermore, the effects of Tween-80 on substrate solubility and C. lini physiological properties were studied. Results showed that the DHEA solubility with 2 % Tween-80 increased by 7.8 times. Meanwhile, the mycelia were integrated and full in the presence of 2 % Tween-80. The analysis on fatty acid profile of the C. lini cell membrane indicated that Tween-80 increases the content of unsaturated fatty acid. All above results suggested that the enhanced product yield caused by Tween-80 was mainly associated with easier substrate-molecule transportation across the cell membrane of C. lini.
7α,15α - 二羟基脱氢表雄酮是新型口服避孕药优思明的关键前体物质。亚麻炭疽菌能够催化脱氢表雄酮（DHEA）的7α和15α位羟基化反应。在本研究中，将亚麻炭疽菌静息细胞应用于DHEA向7α,15α - 二羟基脱氢表雄酮的生物转化过程。在2%（w/v）吐温 - 80存在的情况下，DHEA的转化效率大幅提高。当DHEA浓度为10 g/L时，DHEA转化率和7α,15α - 二羟基脱氢表雄酮产量分别提高了34.6%和87.0%。此外，研究了吐温 - 80对底物溶解度和亚麻炭疽菌生理特性的影响。结果表明，2%吐温 - 80存在时DHEA的溶解度提高了7.8倍。同时，在2%吐温 - 80存在的情况下，菌丝体完整饱满。对亚麻炭疽菌细胞膜脂肪酸谱的分析表明，吐温 - 80增加了不饱和脂肪酸的含量。以上所有结果表明，吐温 - 80导致产物产量提高主要与底物分子更容易穿过亚麻炭疽菌细胞膜进行运输有关。
