【摘要】 目的通过研究突变株拟青霉菌sp229-7(Paecilomyces bainiersp229-7)的生长及转化底物情况,探讨突变株转化三七茎叶总皂苷的高效性。方法在不同条件下,运用摇瓶转化法考查菌株生长和转化底物特性;分别采用静息态细胞、胞外酶以及粗酶液,测定其对底物转化情况。结果菌体12～48 h之间生长最旺盛,36 h加入底物转化率最高,加入底物后72 h转化基本结束,转化产物只有人参皂苷Rd,底物投料量至少可以达到20 mg/mL,克分子转化率达80%以上,转化温度27℃～32℃之间最佳。静息态细胞、胞外酶以及粗酶液都可以将人参皂苷Rb1转化为人参皂苷Rd。结论与文献报道相比,Paecilomyces bainiersp229-7突变株具有良好的底物耐受性和专一性,快速生长的后期是底物投料的最佳时机,Rb1转化为Rd的时间缩短为3 d,投料量至少增加20倍,显著提高了转化效率,可望应用于工业生产。突变株的高转化效率可能与转化酶由细胞内产生并部分分泌到胞外有关,增加了酶与底物接触机会,避免了产物在胞内过量积累。更多还原

【Abstract】 Objective To investigate the mycelia growth of the mutant strain Paecilomyces bainier sp229-7 and it’s biotransformation from ginsenoside Rb1 to Rd. Methods The substrate was biotransformed by the mutant in different conditions,and the products were analyzed by HPLC. Results The period of vigorous growth of the mutant was 12-48 h.The optimal transformation temperature range was from 27 ℃ to 32 ℃.The best time for adding substrate was 36 h after inoculation and the substrate(Rb1 20 mg/mL) was specifically transformed into ginsenoside Rd.The transformation process was terminated at 72 h.The ginsenoside Rb1 could be transformed to Rd by all of mycelia,crude enzymes and external enzymes. Conclusions Compared with the reference,the mutant of Paecilomyces bainier sp229-7 growth is quicker and the transformation efficiency has been greatly improved.The reaction time can be shortened to 3 days,and the amount of substrate increased at least 20 times.更多还原