Abstract: In this paper, the culture conditions for higher antioxidant activity in the culture supernatant of Bifidobacterium animalis subsp. lactis strain B013 were optimized by response surface methodology. The results showed that an inoculum size (defined by OD600 nm) of 0.66, a culture time of 17.84 h and a glucose concentration of 3.04% were determined as the optimal conditions. Treatment with different enzymes and at different temperatures conformed that the antioxidant activity of the culture supernatant was due to the presence of bioactive peptides. A total of 8 peptides were separated and purified by solid phase extraction and ultrafiltration, and they were analyzed by liquid chromatography tandem mass spectrometry. One (QYPLGPK) of the peptides was screened for possible antioxidant activity by bioinformatics and computer simulation. It was verified that the total antioxidant capacity of QYPLGPK at a concentration of 10 mg/mL was (0.249 ± 0.011) mmol Trolox/L.

Key words: antioxidant; probiotics; Bifidobacterium animalis subsp. lactis; bioactive peptide

摘要： 通过响应面法优化动物双歧杆菌乳亚种B013培养物上清液的抗氧化活性，并对其中的生物活性肽进行分 离、鉴定。结果表明：最优的培养体系为菌量（以OD600 nm表示）0.66、培养时间17.84 h、葡萄糖添加量3.04%；通 过不同的酶和温度处理确认，培养物上清液的抗氧化活性来源于其中的生物活性肽；通过固相萃取和超滤对培养物 上清液中的生物活性肽进行分离纯化，产物经过液相色谱-串联质谱分析得出，其中含有8 种肽，通过生物信息学和计 算机模拟筛选出其中1 种肽（QYPLGPK）可能具有抗氧化活性；经过验证，质量浓度10 mg/mL的肽QYPLGPK的总抗 氧化活性为（0.249±0.011） mmol Trolox/L。

关键词: 抗氧化；益生菌；动物双歧杆菌乳亚种；生物活性肽