益生菌切达干酪成熟过程中细菌群落的多样性分析

采用选择性培养基和聚合酶链式反应和变性梯度凝胶电泳（polymerase chain reaction-denaturing gradient gelelectrophoresis，PCR-DGGE）技术，研究益生菌切达干酪成熟过程中（6 ℃，180 d）细菌群落构成及益生菌（干酪乳杆菌LC2W）的存活情况。结果表明：SBM和MSE等选择性培养基存在选择专一性不强的缺点，不能客观反映干酪内各种微生物的动态变化；随着切达干酪成熟时间的增加，发酵剂嗜热链球菌和乳酸乳球菌的数量明显下降，而非发酵剂菌群乳杆菌的数量和主要种类呈上升趋势；干酪成熟180 d后，干酪乳杆菌LC2W的存活量仍高于1×108CFU/g。切达干酪能作为干酪乳杆菌LC2W存活的良好载体；PCR-DGGE技术和选择计数法联用更加适合干酪细菌群落结构的分析。

Diversity of Bacterial Communities of Probiotic Cheddar Cheese during Ripening

The survival of Lactobacillus casei LC2W and the bacterial communities in cheddar cheese were analyzed by
using selective media and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) method during
the ripening period of 180 days at 6 ℃. Results demonstrated that SBM and MSE selective media could not objectively
reflect the dynamic changes of various microorganisms in the cheese due to the poor selectivity. The population of the
starters Streptococcus thermophilus and Lactococcus lactis decreased significantly, while the population and species of the
non-starter Lactobacillus significantly increased during the ripening period. L. casei LC2W survived well in the cheese
and retained its viability at ＞ 1 × 108 CFU/g even after 180 days ripening. It is concluded that cheddar cheese can be
an effective vehicle for delivery of L. casei LC2W and that PCR-DGGE technology combined with traditional culturedependent
methods can be more suitable for cheese microflora analysis.