本研究对10株实验室保存的德氏乳杆菌保加利亚亚种产酸能力，产黏能力，产香能力和贮藏期稳定性进行测定，并通过测定乳酸菌对抗生素的耐药性、抑菌能力、β-半乳糖苷酶（β-Gal）活性、α-半乳糖苷酶（α-Gal）活性和乳酸脱氢酶（LDH）活性探究菌株的益生特性。单菌株发酵实验结果表明：菌株KSDB-1凝乳时间短（6.3 h），凝乳酸度为76.02 °T，具有较好的产酸能力，同时黏度和持水力分别为1305.67 mPa.s和50.55%，显著高于其他菌株（p<0.05）；菌株HDS-13、DDB14、KSDB-1具有较好的产香能力较好，其中菌株HDS-13的双乙酰含量为2.88 mg/L，乙醛含量达到了30.08 mg/L，可有效改善酸奶的风味。益生特性实验结果表明：10株供试菌株对大部分抗生素表现为敏感，具有较高的安全性；菌株HDS-13、DDB-14、HDB-1、HDS-18、KSDB-1对6株致病菌均具有一定的抑制能力，能有效抑制肠道致病菌的生长；菌株HDS-12和KSDB-1乳酸脱氢酶活力较高；菌株HDS-12，HDB-17 β-半乳糖苷酶活力较高；菌株DDS-15 α-半乳糖苷酶活力显著高于其他菌株（p<0.05），达到了1.33 U/mg。综合得出：菌株KSDB-1发酵特性良好，具有一定的益生特性，作为酸乳发酵剂具有潜在的工业应用前景。

The acid-producing, viscosity-increasing, and aroma-producing capacities and laboratory storage stabilities of ten strains of Lactobacillus delbrueckii subsp. bulgaricus were measured. The probiotic characteristics of the strains were also explored by monitoring their antibiotic resistance, antibacterial activities, and β-galactosidase (β-gal), α-galactosidase (α-gal), and lactate dehydrogenase (LDH) activities. Single-strain fermentation experiments show that the strain KSDB-1 had a short coagulation time (approximately 6.3 h), a lactic acid degree of 76.02°T upon coagulation, and good acid-producing ability. The viscosity and water holding capacity (1305.67 mPa?s and 50.55%, respectively) were significantly higher than those of other strains (p<0.05). Aroma production of strains HDS-13, DDB14, and KSDB-1 was superior. Strain HDS-13 displayed a diacetyl content of 2.88 mg/L and an acetaldehyde content of up to 30.08 mg/L. These attributes could effectively improve the flavor of the yoghurt product. Probiotic tests show that all the ten tested strains were sensitive to most antibiotics and thus would be relatively safe to use. Strains HDS-13, DDB-14, HDB-1, HDS-18, and KSDB-1 could inhibit six pathogenic bacteria and effectively inhibited the growth of pathogenic intestinal bacteria. The LDH activities of strains HDS-12 and KSDB-1 were relatively high. The β-gal activities of strains HDS-12 and HDB-17 were relatively greater than that of the other strains. The α-gal activity of strain DDS-15 was significantly higher than those of other strains (p< 0.05), reaching 1.3263 U/mg. The collective data indicate that strain KSDB-1 has excellent fermentation properties and, to a certain degree, satisfactory probiotic properties. DDS-15 has potential in industrial application for yogurt fermentation.

国家自然科学基金项目（31972094；31701627）；国家重点研发计划课题（2019YFF0217602）；江苏省高等学校自然科学研究重大项目（19KJA140004）；成都市重大科技应用示范项目（2019-YF09-00055-SN）；江苏省科技计划项目-苏北科技专项（XZ-SZ201850）