粉葛多糖促植物乳杆菌P9生长代谢及发酵液抗氧化活性研究

Study on the growth and metabolism of Lactobacillus plantarum P9 promoted by Puerariae thomsonii Radix polysaccharide and antioxidant activity of fermentation broth

中文关键词:  植物乳杆菌P9  粉葛多糖  益生元  代谢产物  抗氧化活性

英文关键词:Lactobacillus plantarum P9  Puerariae thomsonii Radix polysaccharide  prebiotics  metabolite  antioxidant activity

中文摘要:

      目的 探究粉葛多糖(Puerariae thomsonii Radix polysaccharide, PRP)对植物乳杆菌P9的促生长代谢作用, 评价其益生作用。方法 配制不同质量分数的PRP液体培养基并接种P9, 检测发酵液OD600值和pH, 考察PRP对P9增殖的影响及P9产酸能力。采用高效液相色谱法、高效液相色谱-质谱法、紫外分光光度计进一步分析添加PRP后, P9发酵液中有机酸、糖类代谢产物变化及其抗氧化活性。结果 添加PRP后, P9发酵液OD600升高, pH下降, MRS+3.0% PRP组达到极值, OD600为3.25, pH为3.56, 表明PRP能促进P9生长且产生了更多的酸性代谢产物, 有机酸测定进一步表明草酸、柠檬酸、苹果酸、琥珀酸、乳酸、甲酸、丙酸均升高, 且产生了蜜二糖、水苏糖、棉子糖3种有益的糖类降解物。抗氧化活性结果表明, MRS+3.0% PRP组1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl, DPPH)自由基清除率和羟基自由基清除率最高, 分别为60.88%和97.41%, 较MRS组分别提高9.29%、29.84%; 各组别总还原能力与PRP质量分数呈正比, 表明添加PRP后, P9发酵液抗氧化活性增强。结论 综上推测PRP具有益生作用, 经与P9培养后, 发酵液抗氧化活性增强, 为PRP作为益生元的开发提供参考。

英文摘要:

      Objective To investigate the pro-growth and metabolic effects of Puerariae thomsonii Radix polysaccharide (PRP) on Lactobacillus plantarum P9 and evaluate its probiotic effect. Methods Different mass fractions of PRP liquid medium were prepared and inoculated with P9, OD600 value and pH of fermentation solution were determined to investigate the effect of PRP on the proliferation of P9 and the ability of P9 to produce acid. The organic acids, sugar metabolites and antioxidant activities in the P9 fermentation broth were further analyzed by high performance liquid chromatography, high performance liquid chromatography-mass spectrometry and ultraviolet spectrophotometer after the addition of PRP. Results The OD600 of P9 fermentation broth increased and the pH decreased after the addition of PRP, and the extreme value was reached in the MRS+3.0% PRP group with OD600 of 3.25 and pH of 3.56, indicating that PRP could promote the growth of P9 and produced more acidic metabolites. The organic acid assay further showed that oxalic acid, citric acid, malic acid, succinic acid, lactic acid, formic acid, and propionic acid were elevated, and 3 kinds of beneficial sugar degradation products, namely melibiose, stachyose and raffinose were produced. The results of antioxidant activity showed that 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging rate and hydroxyl radical scavenging rate were the highest in the MRS+3.0% PRP group with 60.88% and 97.41%, respectively, which were 9.29% and 29.84% higher than the MRS group. The total reducing ability of each group was proportional to the mass fraction of PRP, indicating that the antioxidant activity of P9 fermentation broth was enhanced by the addition of PRP. Conclusion It is speculated that PRP has potential prebiotic effect and the antioxidant activity of the fermentation broth has been enhanced after incubation with P9, which provides a reference for the development of PRP as prebiotics.