冻干保护剂对植物乳杆菌的代谢特性的影响

通过分析植物乳杆菌Lactobacillus plantarum CGMCC 6016(L. P. dy-1)冻干菌粉发酵后胞内游离氨基酸、有机酸、菌体蛋白的谱图变化,对比研究了不同冻干保护剂对L. P. dy-1冻干菌粉代谢特征的影响。结果显示,直接活化组L. P. dy-1的胞内氨基酸总量为625.23 μg/100 μL,10%菊粉保护剂组有所增加,为753.72 μg/100 μL;22.4%菊粉保护剂组、菊粉复合保护剂组和脱脂乳复合保护剂组则相对减少;直接活化组L. P. dy-1的胞内有机酸总量为62.84 mg/L,冻干保护剂组均显著降低,其中菊粉复合保护剂组与直接活化组最为接近,为52.99 mg/L;不同菊粉保护剂组冻干菌粉发酵后,菌体蛋白的谱图较为相近,且与直接活化组差异不大,脱脂乳复合保护剂组较未冻干菌体蛋白谱差异明显,表现为有较多条带的缺失,且谱带较浅。结果表明,与常用的脱脂乳复合保护剂相比,菊粉保护剂,尤其是菊粉复合保护剂的添加,能够使植物乳杆菌冻干菌粉的代谢特性更接近正常组。

Influence on metabolic characteristics of Lactobacillus plantarum by cryoprotectant

The content variation of intracellular free amino acid,organic acid and protein of Lactobacillus plantarum dy-1(L. P. dy-1)were determined. Then the matebolic characteristic of freeze-dried L. P. dy-1 during fermentation affected by different cryoprotectant were compared and studied. The results were as follows:the total amino acid content of activation bacteria group was 625.23 μg/100 μL,and the content of freeze-dried group protected by 10% inulin was increased to 753.72 μg/100 μL,while the amino acid of 22.4% inulin group,inulin composite protective agent group and skim milk composite protective agent group decreased. The total organic acid content of activation bacteria group was 62.84 mg/L,while the content of the freeze-dried bacteria with cryoprotectant decreased significantly. Among them,the total organic acid of inulin composite protective agent group with the content of 52.99 mg/L was most similar with the activation bacteria group. The mycoprotein SDS-PAGE patterns of the freeze-dried bacteria with different types of inulin cryoprotectant were similar,and there was no significant difference with the activation bacteria group. Otherwise,the pattern of the skim milk composite protective agent group was different from the activation bacteria group,which was lack of more electrophoretic bands and the content was less than the other groups. The results indicated that the addition of inulin,especially the inulin composite protective agent would make the metabolic characteristic of freeze-dried L. P. dy-1 more close to the normal group.