Molecular Characterization of Plasmid DNA from Weissella cibaria Isolated from Kimchi

摘要

Four plasmid-harboring lactic acid bacteria were isolated from kimchi and identified. Among them Weissella sp. KLC140, identified according to 16S rRNA sequence, harbored three plasmids of 1.5 kb (pKLCA), 3.4 kb (pKLCB), and 10.0 kb (pKLCC). Nucleotide sequence analysis of pKLCA (1490 bp, 41.5% G+C) revealed one open reading frame (orfAl), whose predicted product consisted of 258 amino acids and showed similarities to several replication proteins of the rolling circle replication (RCR) type. A conserved tyrosine residue necessary for cleavage at the double strand origin was found in orfAl. A pT181-like double strand origin with three inverted repeats was found downstream of orfAl. Nucleotide sequence analysis of pKLCB (3353 bp, 37.2% G+C) showed twoORFs, orfBl predicting a 205-amino-acid protein and orfB2 predicting a 152-amino-acid protein. OrfBl displayed significant sequence similarity with cadmium binding proteins from several bacteria. OrfB2 shared homology with acetyltransferases from several bacteria. This is the first report of the isolation and characterization of novel plasmids from the genus Weissella.