A highly efficient method for concentrating DNA from river water by combined coagulation and foam separation

ABSTRACT

Both Escherichia coli and Enterococci were collected in foam within 7 min from 500 mL of bacteria-spiked water by coagulation and foam separation using ferric chloride and milk casein. These bacterial DNA isolated in the 100 µL of extract from the foam more than 87.5% recovery using the DNeasy PowerWater® Kit. To test this method with water from three natural rivers, 0.67–2.70 µg of DNA were concentrated in 100 µL of extract from 1,000 mL of river water. When the DNA extract was subjected to 16S rRNA gene sequencing analysis, information on the bacterial flora could be obtained.

KEYWORDS:

• Bacteria DNA
• foam concentration
• river water
• 16S rRNA gene sequencing analysis