A simple method for DNA extraction from marine bacteria that produce extracellular materials.

We present a simple method for extracting DNA from the marine bacteria Hahella chejuensis, a Streptomyces sp., and a Cytophaga sp. Previously, DNA purification from these strains was hindered by the presence of extracellular materials. In our extraction method, the marine bacteria are lysed by freezing and grinding in liquid nitrogen, and treated with SDS. The extracted DNA is purified using a phenol/chloroform mixture, and precipitated in isopropanol. The extracted DNA is of high quality and suitable for molecular analyses, such as PCR, restriction enzyme digestion, genomic DNA blot hybridization, and genomic DNA library construction. We used this method to extract genomic DNA from several other marine bacteria. Our method is a reproducible, simple, and rapid technique for routine DNA extractions from marine bacteria. Furthermore, the low cost of this method makes it attractive for large-scale studies.