大豆异黄酮开环转化菌株耐氧突变株脯氨酸体外累积及其抗氧化活性研究  

Study on biosynthesis and antioxidant activity of proline produced in vitro by an oxygen-tolerant bacterium with soy isoflavone bioconverting activity

作　　者：刘玉霞 曹伶俐[1] 窦世娟 王秀伶[1] LIU Yuxia;CAO Lingli;DOU Shijuan;WANG Xiuling(College of Life Sciences,Hebei Agricultural University,Baoding 071001,China;Cangzhou Medical College,Cangzhou 061001,China)

机构地区：[1]河北农业大学生命科学学院,河北保定071001 [2]沧州医学高等专科学校,河北沧州061001

出　　处：《河北农业大学学报》2020年第4期36-42,48,共8页Journal of Hebei Agricultural University

基　　金：国家自然基金项目(31670057);河北省现代农业产业技术体系大豆创新团队资助项目(326-0702-JSNTKSF).

摘　　要：大豆异黄酮转化菌株是一类能将底物大豆异黄酮转化为不同代谢产物的特定细菌菌株。本实验室从公鸡新鲜粪样中分离得到1株能将底物黄豆苷原开环转化为O-Dma的革兰氏阳性严格厌氧梭菌菌株Clostridium sp.AUH-JLC108,经长期耐氧驯化,得到其耐氧突变株Clostridium sp.Aeroto-AUH-JLC108。本研究利用高效液相色谱法对耐氧突变株发酵液中脯氨酸合成动态进行测定,并通过DPPH清除试验以及抗氧化胁迫试验研究脯氨酸的抗氧化活性。结果表明,耐氧突变株Aeroto-AUH-JLC108获得产脯氨酸能力,且脯氨酸产量随菌株培养时间延长而增加,合成的脯氨酸浓度在1~2 mmol/L之间,该浓度下的脯氨酸对DPPH自由基具有明显清除作用。另外,本研究还发现,脯氨酸不仅能够缓解培养基中H2O2对耐氧突变株Aeroto-AUH-JLC108的毒害作用,还可通过保护NADH氧化酶活性减弱氧胁迫对耐氧突变株有氧生长的影响。Soy isoflavone bioconverting microbes are a group of specific bacterial strains,which are capable of bioconverting the substrate soy isoflavones into various metabolites.In our previous study,we isolated a Grampositive strictly anaerobic bacterium designated as Clostridium sp.AUH-JLC108,which was capable of cleaving the C-ring of the substrate daidzein to O-desmethylangolensin(O-Dma)under obligate anaerobic conditions.After longterm oxygen-tolerant domestication,an oxygen-tolerant mutant strain,which we named as Aeroto-AUH-JLC108,was obtained from the original obligate anaerobic bacterium strain AUH-JLC108.In this study,the dynamics of proline production was determined by using HPLC method.Furthermore,the antioxidant activity of proline was examined by both the DPPH scavenging activity and resistance to oxidative stress assays.The results showed that the oxygentolerant mutant strain Aeroto-AUH-JLC108 obtained the proline production capacity.The amount of proline produced by strain Aeroto-AUH-JLC108 increased with the incubation time.The amount of proline produced by strain Aeroto-AUH-JLC108 is between 1 to 2 mmol/L,the concentration of which showed an obvious DPPH free radicalscavenging activity.In addition,we found that the amount of proline produced not only relieved the toxicity of H2O2 but also significantly weakened the oxidative stress on aerobic growth of the oxygen-tolerant bacterium strain Aeroto-AUH-JLC108 by protecting the NADH oxidase activity.

关 键 词：大豆异黄酮转化菌株 耐氧突变株 脯氨酸 抗氧化 

分 类 号：Q935[生物学—微生物学]