WGA
WGA
Although high throughput sequencing is a powerful tool to access the composition of different microbial communities, low biomass environments often possess insufficient amounts of DNA for such analyses.  An example of such an environment is airborne dust that is limited in biomass as well as in the quantity of sample available for analysis. The interest in studying microbial population diversity in intercontinental dust from the Chad Republic, Africa, using culture-independent methods led to a search for protocols that enhance the amount of DNA without compromising the robustness of the analysis.  Whole genome amplification (WGA) is a method that has been used to amplify small amounts of DNA from a variety of samples. Little is known about the bias generated by WGA and the implication of bias in the pyrosequencing results.  To answer this question, DNA was extracted from a sandy soil and used as a model to optimize the protocol for DNA extraction and WGA analyses of the microbial communities that might be found in Chad sand samples. Ribosomal intergenic space analysis and 454 pyrosequencing of amplified 16S rRNA fragments showed that DNA submitted to whole genome amplification differed significantly after whole genome amplification. The 16S rRNA microbial community obtained from WGA had a higher Shannon diversity index and higher rarefaction curves compared with the microbial community obtained without amplification of the template DNA.  Changes observed with WGA were both qualitative and quantitative.