鼠李糖乳酸杆菌降解肌酐和尿酸的活力研究

Lactobacillus rhamnosus mutants in degrading activity of creatinine and uric acid

目的探讨不同条件下诱导和诱变培养鼠李糖乳酸杆菌降解肌酐和尿酸的活力改变。方法在含不同浓度的尿毒症患者混合血清的MRS培养基中诱导培养鼠李糖乳杆菌后,选取降解肌酐和尿酸能力最强的菌株行硫酸二乙酯及紫外线双重多次诱变,测定其肌酐和尿酸降解活力,选出降毒素能力最强的菌株进行遗传稳定性测定。结果 (1)鼠李糖乳酸杆菌诱导420代后开始出现肌酐降解作用,尿酸的降解作用在诱导培养后第390代开始增高,2种毒素均在诱导第480代时降解能力最强。(2)诱导后的乳酸杆菌经过硫酸二乙酯和紫外线复合诱变降解尿毒症毒素的活力明显的提高,其中第5次诱变肌酐的降解活力提升了64.56活力单位(P<0.05);尿酸的降解活力提升了77.66活力单位(P<0.05)。(3)遗传稳定性结果示培养第1代肌酐降解活力127.12活力单位,尿酸降解活力157.55活力单位,第5代分别是127.33、157.32活力单位,没有回复突变。结论诱导后鼠李糖乳酸杆菌经硫酸二乙酯及紫外线双重诱变后能明显的提高肌酐和尿酸的降解能力,且稳定性较好。

Objective To determine the effect of Lactobacillus rhamnosus on the degradation of creatinine and uric acid activity by different inductions and compound mutations. Methods Original Lactobacillus rhamnosus was cultured with different serum levels from uremic patients and then mutated by physical （ultraviolet） and chemical （diethyl sulfate） methods repeatedly. We selected the strains which decreased the concentration of the creatinine and uric acid most and measured its genetic stability. Results （1） The degradation of creatinine occurred in the 420th generation, while degradation of uric acid in the 390th in uremic patients. Lactobacillus rhamnosus degraded both creatinine and uric acid most obviously in the 480th generation. （2） After 5 times of mutation by physical （ultraviolet） and chemical （diethyl sulfate） methods, the Lactobacillus rhamnosus had greater degradation capacity of creatinine and uric acid, and the degradation capacity was increased by 64.56 activity unit and 77.66 activity unit for creatinine or uric acid respectively. （3） The genetic stability of creatinine and uric acid degradation showed that the capacity of creatinine was 127.12 activity unit and that of uric acid was 157.55 activity unit in the first generation, while 127.33 and 157.32 activity unit in the 5th generation respectively, with no reverse mutation. Conclusion After directional induction and compound mutation, Lactobacillus rhamnosus has greater capacity in degrading the creatinine and uric acid.