沼泽红假单胞菌粗酶液生物转化柚皮苷

Biotransformation of naringin by crude enzyme from Rhodopseudomonas palustris

目的初步探索沼泽红假单胞菌粗酶液生物转化柚皮苷的特点。方法利用高效液相色谱技术,以柚皮苷的降解率为指标,考察不同温度、pH、底物浓度和培养时间对粗酶液降解柚皮苷的影响。在适宜转化条件下,探索底物和产物的含量变化。结果最适转化条件:40℃~50℃,pH 7.0~8.0,最大有效转化底物浓度750μg/mL,15 h时柚皮苷降解率较高为55.31%。在最适转化条件下,底物浓度500μg/mL,培养至17 h柚皮苷被降解完全,柚皮素浓度达到最大值204μg/mL,转化率为85.39%;10~19 h,转化率均大于80.00%,13 h达到最大值94.83%。结论本研究首次发现沼泽红假单胞菌粗酶液能够生物转化柚皮苷,并阐明了不同培养条件对柚皮苷降解的影响,以及转化过程中物质含量的变化。

Objective To preliminarily explore the conditions of biotransformation of naringin by crude enzyme from Rhodopseudomonas palustris.Methods HPLC technique was used to explore the effects of temperature,pH,substrate concentration and cultivation period on the degradation of naringin by crude enzyme from Rhodopseudomonas palustris,as well as the changes of the concentrations of substrates and products under suitable culturing conditions.Results The optimum culturing conditions were as follows：a temperature of 40℃-50℃,pH 7.0-8.0,and a concentration of substrate at 250-750μg/mL.Under such a condition,the degradation rate of naringin was up to 55.31%when the cultivation period was 15 hours.With the concentration of substrate at 500 μg/mL,naringin was degraded completely within 17 hours under the optimal condition,and the concentration of naringenin reached the maximum of 204 μg/mL,with the conversion rate being 85.39%.The conversion rate was greater than 80.00%when the cultivation period was between 10 and 19 hours,and reached the peak value of 94.83%at 13 hours.Conclusion The study revealed for the first time that the crude enzyme from Rhodopseudomonas palustris can biotransform naringin,and explored the effects of culturing conditions on naringin degradation,as well as the changes of the contents of substances in the transformation process.