Lactobacillus delbrueckii subsp. bulgaricus (L. bulgaricus) is a microaerophylic anaerobe, which is widely used in the production of yogurt, cheese, and other fermented dairy products. L. bulgaricus and its partner Streptococcus thermophilus were used as starter cultures of yogurt in the world for thousands of years. In our previous study, L. bulgaricus LDB-C1 was obtained from traditional fermented milk, and possessed some characteristics like high exopolysaccharide yield and good fermentation performance. The analysis of its CRISPR-Cas system, antibiotic resistance, virulence factors, and mobile elements, was performed to reveal the stability of the strain LDB-C1. It was found that LDB-C1 contains a plenty of spacers in the CRISPR region, indicating it might have better performance against the infection of phages and plasmids. Furthermore, the acquired or transmittable antibiotic resistance/virulence factor genes were absent in the tested L. bulgaricus strain LDB-C1.
Keywords: Antibiotic resistance genes; CRISPR–Cas system; Lactobacillus delbrueckii subsp. bulgaricus; Mobile elements; Virulence factors.
© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.