454 sequencing of pooled DNA extracts
The V1-V2 region of the 18S rDNA was amplified from the pooled known mixture of 37 species extracts using the primer pair SSU_F04 and SSU_R22. PCR products were subsequently purified using QIAquick© PCR Purification (Qiagen, Hilden, Germany) and then divided into two aliquots (70 µl each) per sample, which served as templates to construct the amplicon library. Further processing of the sample aliquots and 454 sequencing were performed by GATC Biotech (Constanz, Germany).