Elaboration of an electroporation protocol for Lactobacillus brevis

摘要

A detailed electroporation protocol had been established for Lactobacillus brevis TCCC13007. To optimize the conditions for electroporation of L. brevis TCCC13007, an E. coli-Lactobacillus shuttle vector, pMG36e-1 was used. Several experiments that involved manipulation of cell wall weakening agent, electric field strength, electroporation buffer, concentration of transforming plasmid were carried out. Treatment of the recipient L. brevis TCCC 13007 with 2% glycine in the growth medium for 3 h improved transformation efficiency. Other electroporation parameters were an electric field strength of 10 kv/cm and plasmid concentration of 0.9 μg. The presence of sorbitol in the electroporation buffer improved the transformation efficiency. Under the optimal conditions, the transformation efficiency was up to 5.1 × 10~4 transformants per μg of pMG36e-1. The L. brevis TCCC 13007 was also transformed by other plasmids such as pMG36e, pMG36e-2, pGK12, pLP825, pLP82H, respectively. The ability to electroporate plasmid DNA provided a tool for Lactobacillus' s molecular bioengineering to improve their industrial performance.