一株酸面团源乳酸菌的益生特性及其对刺五加叶总皂苷的影响

为了评价前期分离的一株酸面团源菌株HUCM105的益生特性及其对刺五加叶总皂苷含量的影响，通过形态学特征及16S rDNA基因序列分析鉴定种属，分别于pH2.0、pH2.5和pH3.0的酸性环境及0.5%胆汁环境培养3 h，并监测活菌数变化，于富含胆固醇的培养基中培养24 h并监测胆固醇含量的变化，以评价菌株HUCM105的益生特性，随后以刺五加叶水提液为唯一基质，经菌株HUCM105静置或振荡培养72 h，同时监测活菌数和刺五加叶总皂苷含量的变化。结果表明，菌株HUCM105被鉴定为短乳杆菌，其对酸和胆汁均展现出了良好的耐受性，在pH高于2.5和0.5%胆汁环境下培养3 h活菌数均无明显变化。菌株HUCM105体外培养24 h，可去除培养基中26.4%的胆固醇。菌株HUCM105静置或振荡培养于刺五加叶水提液中24 h时活菌数达到最高值，约为5×108 CFU/mL水平。菌株HUCM105静置培养对刺五加叶总皂苷含量无显著影响，而振荡培养可明显提高总皂苷水平，振荡培养48 h时刺五加叶总皂苷含量最高，达42.6 μg/mL，较未接种菌株提高了79.0%。总之，短乳杆菌HUCM105展现出了良好的酸和胆汁耐受性及降胆固醇的益生特性，在刺五加叶水提液中生长良好，并可提高其总皂苷水平，在开发刺五加叶益生菌发酵产品方面具有潜在的应用价值。

The Probiotic Properties of a Strain of Sourdough-derived Lactic Acid Bacteria and Its Effect on the Total Saponins of Acanthopanax senticosus Leaves

The purpose of this paper was to evaluate the probiotic properties of a previously isolated strain HUCM105 from sourdough and its effect on the total saponins of Acanthopanax senticosus leaves. The genus and species was identified by the morphological properties and 16S rDNA gene sequences analysis of strain HUCM105. In order to evaluate the probiotic properties, the number of viable bacteria of the strain HUCM105 was monitored at the acidic environment of pH2.0, pH2.5, and pH3.0 and the 0.5% bile environment incubated for 3 h, respectively, and the change of cholesterol content in the cholesterol-rich medium was determined after fermentation of the strain HUCM105 for 24 h. Subsequently, the aqueous extract of Acanthopanax senticosus leaves was used as the sole substrate, and the number of viable bacteria and the total saponin content of Acanthopanax senticosus leaves were measured under static or shaking incubation for 72 h by the strain HUCM105. The results suggested that the strain HUCM105 was identified as Lactobacillus brevis, and exhibited a good tolerance to acid and bile. The number of viable bacteria had no significant changes in a pH value higher than pH2.5 and 0.5% oxgall for 3 h, respectively. Moreover, the strain HUCM105 could remove 26.4% of the cholesterol in the culture medium supplemented with cholesterol after incubation for 24 h. The number of viable cell of the strain HUCM105 was higher and reached the level of 5×108 CFU/mL through the static or shaking incubation at 24 h in the aqueous extract of Acanthopanax senticosus leaves. Static incubation of the strain HUCM105 had no significant effect on the total saponins content of Acanthopanax senticosus leaves, while shaking incubation could significantly increase the total saponins level. The total saponins content of Acanthopanax senticosus leaves was higher when shaking incubation of the strain HUCM105 for 48 h, and reached 42.6 μg/mL, which was 79.0% higher than that of no strain inoculation. In conclusion, it suggested that the strain HUCM105 exhibited probiotic properties including good tolerance to acid and bile and cholesterol removal ability, could grow well in the aqueous extract of Acanthopanax senticosus leaves and increase the total saponins level of Acanthopanax senticosus leaves, and showed a potential application value as a probiotic candidate strain to develop probiotic fermentation products of Acanthopanax senticosus leaves.