离子液体介质中17α-羟基-16β-甲基孕甾-4,9(11)二烯-3,20-二酮微生物脱氢研究

摘要

考察了亲水性离子液体/Tris-HCl缓冲液混合溶剂体系中简单节杆菌催化甾类化合物17α-羟基-16β-甲基孕甾-4,9(11)二烯-3,20-二酮(简称HMPDD)的C1,2脱氢生成17α-羟基-16β-甲基孕甾-1,4,9(11)三烯-3,20--酮(简称HMPTD)的反应过程,通过细胞相容性和对反应影响的研究,选择了[EMIM]( L)-Lac作为用于该体系的离子液体,并对离子液体体积分数、初始底物质量浓度、菌体质量浓度和反应时间等条件进行了优化.结果表明,在含体积分数为0.3％的[EMIM](L)-Lac的Tris-HCl缓冲液(0.05 mol/L,pH 7.5)体系中,当菌体干重质量浓度为13.1 g/L,底物质量浓度为4 g/L时,简单节杆菌催化HMPDD脱氢反应16 h的转化率可达89.9％,较Tris-HCl缓冲液介质中的脱氢转化率提高10％,且反应时间缩短了8h.%The dehydrogenation of 17crHydroxy-16|3-methylpregna-4, 9 ( 11 )-diene-3, 20-dione (HMPDD) to 17a-Hydroxy- 16p-methylpregn-l ,4,9(11 )-triene-3,20-dione (HMPTD) catalyzed by Arthrobacter simplex was performed in a mixed solvent containing ionic liquid and Tris-HCl buffer(0. 05 mol/L,1 pH 7. 5). The influences of some reaction parameters were investigated. The optimal values of [EMIM](L)-Lac content, cell concentration, substrate concentration and reaction time are 0. 3%, 13. 1 g/L, 4 g/L and 16 h, respectively. Under the optimum conditions, a maximum conversion rate of 89. 9% was obtained, with an increase of 10% compared to that in Tris-HCl buffer. The reaction time with maximum conversion rate was 8 h shorter in the ionic liquids containing system.