A simple, efficient and universal method for the extraction of genomic DNA from bacteria, yeasts, molds and microalgae suitable for PCR-based applications

Abstract

The extraction of genomic DNA from microbial cells plays a significant role in PCR-based applications such as molecular diagnosis, microbial taxonomy, screening of genetically engineered microorganisms, and other such PCRbased applications. Currently, many methods for extraction of genomic DNA from microorganisms have been developed. However, these methods either require hazardous chemicals or consist of time-consuming steps for effective execution. In this study, we have established a simple and universal genomic DNA extraction method for different microorganisms including bacteria, yeasts, molds, and microalgae. Our method does not require harmful reagents such as phenol and chloroform for the extraction process to minimize the generation of hazardous wastes. The obtained genomic DNA products displayed high concentrations and represented a good purity level with the average 260 nm/280 nm absorbance ratios (A_260/280) that range from 1.6 to 2.0. The DNA molecules further remained considerably intact when analyzed on agarose gels. More importantly, these DNA products were qualified through successful PCR amplifications of 16S rRNA gene, rDNA internal transcribed spacer (ITS), or 18S rRNA gene from genomes of bacteria, fungi, and microalgae respectively. Furthermore, with the extracted genomic DNA products, the processes of the identification of the haploid and diploid states of the Saccharomyces yeast strains or detection of putative strains of Aspergillus oryzae and Aspergillus flavus that have been isolated from infected food materials through PCR analyses are facilitated. The genomic DNA extraction method established in this study is easy to manage, time saving and costeffective, and environmentally friendly.