【摘要】 【目的】评估干酪乳酪杆菌Zhang(Lactobacillus casei Zhang,LCZ)在连续传代培养过程中的遗传稳定性。【方法】在MRS液体培养基中连续培养LCZ 100代，分别在第0、25、50、75、100代取样，分析其菌体形态、碳水化合物利用情况及基因组变化。【结果】LCZ在第0、25、50、75、100代的菌体形态及碳水化合物利用情况无显著差异。基因组大小和GC占比在不同代数与原始基因组相比均无显著差异。SNP突变分析显示，不同代数的LCZ基因组高度保守，突变频率较低。平均核苷酸一致性（ANI）和系统发育树结果表明，不同代数的LCZ与原始基因组亲缘关系接近。不同代数的菌株所注释到的碳水化合物活性酶（CAZymes）无显著差异，表明其碳水化合物利用能力一致。【结论】LCZ在连续传代过程中表现出较高的遗传稳定性。更多还原

【Abstract】 [Objective] This study aimed to evaluate the genetic stability of Lactobacillus casei Zhang(LCZ) during continuous passaging. [Method] LCZ was continuously cultured for 100 generations in MRS liquid medium, with samples collected at generations 0, 25, 50, 75, and 100. The morphology, carbohydrate utilization, and genomic changes of LCZ were analyzed. [Result] No significant differences were observed in the morphology and carbohydrate utilization of LCZ across generations 0, 25, 50, 75, and 100. The genome size and GC proportion showed no significant differences compared to the original genome. SNP mutation analysis indicated that the LCZ genome was highly conserved across generations, with a low mutation frequency. Average nucleotide identity(ANI) and phylogenetic tree analyses revealed that the LCZ strains from different generations were closely related to the original genome. No significant differences were found in the annotations of the carbohydrate-active enzyme(CAZymes) among different generations, suggesting consistent carbohydrate utilization ability. [Conclusion] LCZ exhibited high genetic stability during continuous passaging.更多还原