14A-27 |
The optimal conditions of electrotransformation for Lactobacillus acidophilus strains |
Y. H. KIM1, K. S. Han, S. J. Oh, S. You4, and S. H. Kim. (1) Division of Food Science, Korea University, 1, 5-ka, Anam-Dong, Sungbuk-ku, Seoul, 136-701, South Korea, (2) Division of Biotechnology & Genetic Engineering, Korea university, 1, 5-ka, Anam-Dong, Sungbuk-ku, Seoul, 136-701, South Korea Transformation studies of Lactobacillus strains have been continuously developed along with the attempt to use as vehicles of heterogous protein expression and oral vaccines. Genetic technology including conjugation, protoplast, and electroporation has been used to improve the desired-characteristics of lactic acid bacteria (LAB). This study was conducted to find the optimum conditions of pulse strength, pulse interval and plasmid DNA concentration for electroporating foreign plasmid DNA into Lactobacillus acidophilus ATCC 43121. We also observed differences in electroporation efficiencies between L. acidophilus strains and other lactobacilli (L. casei, L. plantarum, L. helveticus, and L. rhamnosus). The pNZ123 is broad host-range and low copy number vector, which contains the origin of replication derived from the cryptic Streptococcus lactis plasmid pSH71. It is 2.8kb in size and contains genes for resistance to chloramphenicol. The optimum conditions of the electroporation parameters for maximum transformation efficiency were 12.5 kV/cm pulse strength, 10 set pulse numbers, 500 ms pulse intervals, and 25 ng/ml plasmid concentration with 1.84 x 104 transformants per plasmid DNA in L. acidophilus ATCC 43121. However, the transformation efficiency was strongly influenced by varied the different strains among tested in this study. The availability of a reproducible and efficient transformation conditions could facilitate the cloning of foreign genes into L. acidophilus ATCC 43121 as potential live vaccine vehicles.
Session 14A, Dairy Foods: General developments in dairy technology I
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