Rapid PCR-based method which can determine both phenotype and genotype of Lactococcus lactis subspecies.
A highly efficient, rapid, and reliable PCR-based method for distinguishing Lactococcus lactis subspecies (L. lactis subsp. lactis and L. lactis subsp. cremoris) is described. Primers complementary to positions in the glutamate decarboxylase gene have been constructed. PCR analysis with extracted DNA or with cells of different L. lactis strains resulted in specific fragments. The length polymorphism of the PCR fragments allowed a clear distinction of the L. lactis subspecies. The amplified fragment length polymorphism with the primers and the restriction fragment length polymorphism of the amplified products agreed perfectly with the identification based on genotypic and phenotypic analyses, respectively. Isolates from cheese starters were investigated by this method, and amplified fragments of genetic variants were found to be approximately 40 bp shorter than the typical L. lactis subsp. cremoris fragments.
Nomura
Masaru
M
Department of Animal Products Research, National Institute of Livestock and Grassland Science, Norindanchi, Tsukuba 305-0901, Japan. nomura@affrc.go.jp
Kobayashi
Miho
M
Okamoto
Takashi
T
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D004269:DNA, Bacterial / Q000032:analysis; D005838:Genotype; D013294:Lactococcus lactis / Q000145:classification* / Q000235:genetics; D008969:Molecular Sequence Data; D010641:Phenotype; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S