人肠道产柚苷酶菌株分离、鉴定及其对柚皮苷的转化特性

Isolation，identification and naringin biotransforming properties of naringinase producing bacteria isolated from human intestinal microflora

摘要:

摘要:【目的】从健康人肠道微生物菌群中分离能将柚皮苷高效转化为柚皮素的特定细菌菌株，对分离得到的菌株进行菌种鉴定并研究菌株对柚皮苷转化特性，目的是为柚皮素的高效生物合成提供新细菌资源。【方法】取健康人新鲜粪样，在厌氧工作站内培养24 h 后进行梯度稀释并涂板，从板上挑取单菌落与底物柚皮苷进行厌氧培养，用高效液相色谱检测底物被转化情况。根据16S rDNA序列及相关生理生化特性分析，对所分离的柚皮苷转化菌进行菌种鉴定，并测定转化菌株对底物柚皮苷的转化动态和转化能力。【结果】从人肠道菌群中分离得到4株能将柚皮苷转化为柚皮素的细菌菌株，分别命名为AUH-JLD3、AUH-JLD7、AUHJLD104和AUH-JLD109。根据16S rDNA序列分析，结合形态学及相关生理生化特性等，将其分别鉴定为布劳特氏菌(Blautia sp． AUH-JLD3)、肠球菌(Enterococcus sp． AUH-JLD7)、拟杆菌(Bacteroides sp．AUHJLD104)和巴氏链球菌(Streptococcus pasteurianus subsp．AUH-JLD109)。转化动态研究结果表明，所分离的4株细菌菌株均能在12 h内将0.2 mmol/L底物柚皮苷转化为柚皮素;转化能力测定结果显示，菌株AUHJLD3、AUH-JLD7、AUH-JLD104及AUH-JLD109能够高效转化底物柚皮苷的最大浓度分别为0.2 mmol/L(平均转化率66.67%)、0.8 mmol/L(平均转化率86. 49%)、0.2 mmol/L(平均转化率73.68%)以及1.6 mmol/L(平均转化率93.20%)。【结论】本研究首次从人肠道菌群中分离得到4 株能将柚皮苷转化为柚皮素的细菌菌株，其中巴氏链球菌AUH-JLD109对底物柚皮苷转化能力最强。

Abstract:

Abstract:［Objective］ Isolation of specific bacteria from human intestinal microflora to convert naringin to naringenin efficiently． ［Methods］Fresh human feces from healthy individual was cultured in an anaerobic chamber for 24 h before being diluted and spread on agar medium．We cultured and incubated each single colony with the substrate naringin．The biotransformation of naringin by each single colony was detected by high-performance liquid chromatography (HPLC). We identified the isolated bacteria based on the analyses of 16S rDNA sequence and biochemical traits．We also studied the bioconversion kinetics of the bacteria．［Results］Four bacterial strains，named AUH-JLD3，AUH-JLD7，AUH-JLD104 and AUH-JLD109，capable of biotransforming naringin to naringenin，were isolated and identified as Blautia sp．AUHJLD3，Enterococcus sp． AUH-JLD7，Bacteroides sp．AUH-JLD104 and Streptococcus pasteurianus subsp．AUH-JLD109 respectively based on the 16S rDNA sequence analysis，bacterial cell morphology，and biochemical traits． Study on biotransforming kinetics showed that all the four isolated bacterial strains were able to convert naringin (0.2 mmol/L) to naringenin within 12 h．The maximal concentration of the substrate naringin that strain AUH-JLD3，strain AUH-JLD7，strain AUH-JLD104 and strain AUH-JLD109 could biotransform efficiently were 0.2 mmol/L (the average biotransforming rate was 66.67%)，0.8 mmol/L (the average biotransforming rate was 86.49%)，0.2 mmol/L (the average biotransforming rate was 73.68%) and 1.6 mmol/L (the average biotransforming rate was 93.20%)，respectively.［Conclusion］ The four bacterial strains were capable of biotransforming naringin to naringenin， among which Streptococcus pasteurianus subsp．AUH-JLD109 has the highest naringin biotransforming capacity.