Selected characteristics of several strains of Lactobacillus plantarum.

Several relevant characteristics have been studied in nine Lactobacillus plantarum strains isolated from Cabrales cheese. They fermented lactose efficiently and possessed both beta-galactosidase and beta-phosphogalactosidase activities, but no significant proteolytic activity was detected. Antimicrobial susceptibility tests revealed no high level resistance to any of the fourteen compounds tested. All the strains had a high content of extrachromosomal DNA of unknown function. A recombinant plasmid comprising pUC19 from Escherichia coli and a small cryptic plasmid from L. plantarum has been constructed and may be used to develop a shuttle vector for these species.