Improvement of electroporation-mediated transformation efficiency for Bifidobacterium animalis AR668.

Bifidobacterium can be used as probiotic that confers various health benefits to its host. The functional analysis of specific genes can help elucidate the probiotic mechanism of Bifidobacterium. However, the low transformation efficiency has hindered the in-depth study of its function by genetic manipulation. In this study, we optimized transformation methods for Bifidobacterium animalis AR668 to improve the transformation efficiency up to 2.15 ×10⁵ CFU/μg DNA. Additionally, the expression of competence gene ssb2 could enhance the transformability which was the first attempt to apply it to B. animalis. Moreover, the transformation efficiency was increased after the plasmids were modified by gene0033 and gene1509 which limited the interference of the restriction-modification system in the uptake of foreign DNA by cells. Based on the above optimization, the transformation efficiency of 7.2 ×10⁵ CFU/μg DNA for AR668 was obtained, which was more than 100 times higher than that of the original condition. Together, we successfully improved the transformation efficiency of B. animalis AR668, contributing to its genetic manipulation and modification. [ABSTRACT FROM AUTHOR]