该研究对酸马奶中分离的197株乳酸菌进行潜在益生作用菌株的筛选鉴定及生物学特性研究。通过耐酸性试验和耐胆盐能力试验初步筛选出10株耐受能力较好的菌株，经过模拟人工胃液处理3 h后10株菌的存活率在46.48%~95.86%之间，选取存活率大于80%的3株菌进行模拟人工肠液试验（处理4 h和8 h后），活菌数均保持在1.65×109~1.81×1010 CFU/mL之间，并且3株菌均有一定的疏水能力。其中，菌株2-33在模拟人工胃液中存活率达95.86%、模拟人工肠液中存活率达80.80%、细胞表面疏水性为42.61%，因此将菌株2-33确定为目的菌株。从抗生素药敏试验可知，菌株2-33对诺氟沙星、头孢拉定、庆大霉素、万古霉素以及链霉素有耐药性，不敏感；对克林霉素中度敏感；对四环素、氯霉素、红霉素、氨苄西林敏感。最后，经分子生物学确定菌株2-33的16S rDNA基因序列长度为1432 bp，在NCBI中基因登录号为MN611708，与L. plantarum JCM1149同源性达100%，并且菌株2-33的糖类发酵试验结果与GB 4789.35-2016一致，所以将菌株2-33鉴定为植物乳杆菌。该研究结果对今后益生菌的深入研究和功能性食品的开发提供材料。

197 strains of lactic acid bacteria isolated from sour horse milk were screened and identified, and their biological characteristics were studied. In acid tolerance assays and bile salt tolerance assays, ten strains with relatively high tolerance were preliminarily selected. The survival rates of the ten strains after three hours of treatment with artificial gastric juice were between 46.48% and 95.86%. Among them, three strains with survival rates higher than 80% were selected and subjected to artificial intestinal fluid treatment for four and eight hours. After that, the numbers of live bacteria were determined: 1.65×109 to 1.81×1010 colony-forming units per milliliter. Furthermore, the three strains all exhibited certain hydrophobicity. Among them, the survival rates of strain 2-33 in artificial gastric juice and artificial intestinal fluid reached 95.86% and 80.80%, respectively, with cell surface hydrophobicity of 42.61%. Thus, strain 2-33 was identified as the target strain (a potential probiotic). An antibiotic sensitivity assay showed that strain 2-33 is resistant to norfloxacin, cefradine, gentamicin, vancomycin, and streptomycin; moderately sensitive to clindamycin; and sensitive to tetracycline, chloramphenicol, erythromycin, and ampicillin. Finally, the 16S ribosomal DNA gene sequence of strain 2-33 was determined by a molecular biological method; this gene’s length was found to be 1432 bp. The accession number in NCBI is MN611708. Stain 2-33 showed 100% homology with Lactobacillus plantarum JCM1149, and sugar fermentation assay results on this strain are consistent with those of GB 4789.35-2016; therefore, the strain was identified as L. plantarum. The results of this study provide data for further research on probiotics and the development of functional foods in the future.

内蒙古自治区科技计划重大专项项目（2020CG0012）；政府间国际科技创新合作重点专项（2017YFE0108700）；内蒙古自治区高等学校科学研究项目（NJZY19054）