自然发酵东北酸菜中抗氧化乳酸菌的筛选及其益生性研究

Screening of high antioxidant activity lactic acid bacteria in traditional fermented Suancai of northeast China and its prebiotic studies

中文关键词:  乳酸菌  抗氧化  筛选与鉴定  东北酸菜

英文关键词:lactic acid bacteria  antioxidant  screening and identification  Suancai of northeast China

中文摘要:

      目的 从自然发酵酸菜样品中筛选具有抗氧化活性的乳酸菌为蔬菜发酵提供优良菌种。方法 将筛选获得的71株乳酸菌经平板划线纯化培养, 去除生长性差和遗传性能不稳定的菌株, 筛选出23株乳酸菌进行抗氧化性能初筛, 经初筛得到6株具有较好抗氧化潜力的乳酸菌。基于还原能力和自由基清除能力复筛并将具有最强抗氧化能力的菌株与常用的天然抗氧化剂, 即抗坏血酸做对比, 同时进行益生性研究, 最后利用16S rRNA基因的序列对其进行鉴定。结果 初筛得到的6株乳酸菌均具有较好的抗氧化能力, 且大部分菌株的菌体悬液抗氧化能力大于无细胞提取物。经益生性分析, 所筛选6株乳酸菌理论上可通过胃肠环境定植于肠道并都属于高疏水性菌株。具有较高抗氧化活性的乳酸菌为SC3, 其还原能力相当于270.58 μmol/L L-半胱氨酸, 其菌体悬液清除羟基自由基的能力(45.28%)显著高于0.1 mg/mL抗坏血酸(P<0.05), 清除1,1-二苯基-2-三硝基苯肼自由基的能力(43.66%)与0.1 mg/mL抗坏血酸相近, 其发挥抗氧化作用的关键为菌体悬液。结论 SC3经鉴定为植物乳杆菌(Lactiplantibacillus plantarum), 具有良好的抗氧化性。本研究结果可为具有抗氧化功能的乳酸菌筛选提供参考。

英文摘要:

      Objective To screen lactic acid bacteria with antioxidant activity from naturally fermented Suancai samples to provide excellent strains for vegetable fermentation. Methods The 71 strains of lactic acid bacteria sifted out were purified and cultured by plate scribing, the strains with poor growth and unstable genetic performance were removed, 23 strains of lactic acid bacteria were screened for antioxidant performance, and 6 strains of lactic acid bacteria with antioxidant potential were obtained by the initial screening. Based on the reducing ability and free radical scavenging ability, the strain with the strongest antioxidant ability was screened and compared with the commonly used natural antioxidant, namely ascorbic acid. At the same time, the prebiotic study was conducted. Finally, the 16S rRNA gene sequence was used to identify the strain. Results The 6 strains of lactic acid bacteria obtained by the initial screening all had certain antioxidant capacity, and the antioxidant capacity of the intact cells of most strains was greater than that of the cell free extracts. After probiotic testing, 6 strains of lactic acid bacteria could theoretically colonize the intestine through the gastrointestinal environment and were all highly hydrophobic strains. The lactic acid bacteria with high antioxidant activity was SC3, whose reducing capacity was equivalent to 270.58 μmol/L L-cysteine, the ability of bacterial suspension to scavenge hydroxyl radicals (45.28%) was significantly higher than that of 0.1 mg/mL ascorbic acid (P<0.05), and the ability to scavenge 1,1-diphenyl- 2-picrylhydrazyl radicals (43.66%) was similar to that of 0.1 mg/mL ascorbic acid, and the key to its antioxidant effect was the intact cells. Conclusion SC3 is identified as Lactiplantibacillus plantarum, which has good antioxidant activity. The results of this study can provide a reference for the screening of lactic acid bacteria with antioxidant function.