2.3. Preparation of genomic DNA
Genomic DNAwas prepared fromovernight cultures grown onMILS
lactose broth according to Anderson and McKay (1983). Spheroplasts
preparedwith lysozyme(Sigma) (500 μg/mL) and N-acetylmuramidase
SG (Seikagaku Corporation, Tokyo, Japan) (50 μg/mL) were lysed with
1 % sodium dodecylsulfate and 250 μg/mL proteinase K at 65 °C, and
genomicDNAwas precipitatedwith ethanol after extraction of resultant
cleared lysate with phenol and chloroform.