A capillary electrophoresis method for selective simultaneous determination and quantitation of native amino acids and lactic acid during cultivation of Lactobacillus helveticus D75 and D76 strains on the MRS-1 and milk nutrient media was presented. The method provided sensitive UV-detection of native analytes with minimum sample preparation and appeared to be extremely useful for the analysis of culture media. Native amino acids and lactic acid were separated and detected as complexes with Cu²⁺ ions, while proposed application of β-cyclodextrin (β-CD) and its charged and uncharged derivates (sulfated β-CD and 2-hydroxypropyl-β-CD) as pseudo stationary phases provided better separation selectivity. The effect of CDs, Cu²⁺, sodium acetate, β-CDs concentrations and pH of background electrolyte (BGE) on the electrophoretic mobilities of AAs was thoroughly investigated. The composition of the BGE was found to be as follows: 20 mM acetate buffer solution, 50 mM CuSO₄, 10 mM 2-hydroxypropyl-β-CD, pH 4.3. The developed method possessed high analysis-to-analysis and day-to-day repeatability of migration times (RSD ≤ 1.0% and ≤ 2.5%, respectively). The differences in production of amino acids by D75 and D76 strains grown together and separately were found and concluded to be a consequence and/or one of the causes of synergism and syntropy of the strains. The developed method proved to be applicable for the analysis of culture media.

提出了一种毛细管电泳方法，用于在MRS-1和牛奶营养培养基上培养瑞士乳杆菌D75和D76菌株的同时选择性测定和定量天然氨基酸和乳酸。该方法以最少的样品制备就可对天然分析物进行灵敏的UV检测，对于分析培养基非常有用。分离天然氨基酸和乳酸，并将其检测为与Cu ²⁺离子的络合物，同时建议应用β-环糊精（β-CD）及其带电和不带电衍生物（硫酸化β-CD和2-羟丙基-β-CD）因为伪固定相提供了更好的分离选择性。CD，Cu ^2+的影响深入研究了乙酸钠，β-CDs浓度和背景电解质（BGE）对AA电泳迁移率的影响。所述BGE的组合物，被认为是如下：20mM醋酸缓冲液，50mM的硫酸铜₄，10mM的2-羟基丙基β-CD，pH为4.3。所开发的方法具有很高的分析到分析和迁移时间的日常可重复性（分别为RSD≤1.0％和≤2.5％）。发现并一起生长的D75和D76菌株在氨基酸生产上的差异是结论和/或是该菌株协同和同性的原因之一。实践证明，该方法适用于培养基的分析。