Microcin V Production in Lactobacillus plantarum LB-B1 Using Heterologous Leader Peptide from Pediocin PA-1.

Lactobacillus strains producing bacteriocins have attracted highly attention as probiotic cultures in animal nutrition since the use of antibiotics was forbidden in the livestock industry. Lactobacillus plantarum LB-B1 isolated from the fermented dairy product can produce pediocin PA-1, which has a strong inhibition of Listeria but hardly any influence on Gram-negative spoilage agents. In this work, L. plantarum LB-B1 was selected as the host to express microcin V using the leader peptide of pediocin PA-1. Well-diffusion assay combined with Tricine-SDS-polyacrylamide gel showed that microcin V could be successfully expressed and secreted in L. plantarum LB-B1. Meanwhile, the production of microcin V did not affect the secretion of pediocin PA-1. It is worthwhile noted that the supernatant from L. plantarum 8148-ColV had a more effective inhibition of Listeria than that from the control strain L. plantarum 8148. Furthermore, this supernatant also unexpectedly produced antibacterial activity against Staphylococcus aureus. Taken altogether, these results suggested that pediocin PA-1 and microcin V in the supernatant could generate synergistic effect, which not only enhanced the antibacterial ability but also expanded the antibacterial spectrum. Therefore, the recombinant strain has a great potential application as a probiotic to reduce the level of enteric pathogens in livestock industry.