Microbial genomic DNA was extracted using a QIAamp
DNA Mini kit (Qiagen Inc., USA), quantified with QuantiFluor
dsDNA kit (Promega, Inc.) using a Turner TBS-380 minifluorometer
(Turner BioSystems, USA) and verified with Agilent DNA 1000 kit
on Agilent Bioanalyzer 2100.