Genomic DNA was extracted from the pellet of an overnight culture in MRS broth and purified using a purification kit (Wizard, Genomic, Promega, Wisconsin) following manufacturer's recommendations. The 16S rRNA gene sequence (corresponding to positions 27–1492 in the Escherichia coli gene) was PCR amplified as described by DeLong (1992), using a DNA thermal cycler Mastercycler (Eppendorf, Hamburg, Germany). Sequencing on both strands of PCR-amplified fragments was performed using the dideoxy chain termination method by the commercial services of Macrogen Inc. (Seoul, Korea). The 16S rRNA homology searches against the NCBI database were carried out using BLAST program (Altschul, Gish, Miller, Myers, & Lipman, 1990). Sequence was deposited at the GenBank database.