ZymoBIOMICS™ Microbial Community Standard is a mock microbial community consisting of eight bacterial and two fungal strains. It includes three easy-to-lyse Gram-negative bacteria (e.g. Escherichia coli), five tough-to-lyse Gram-positive bacteria (e.g. Listeria monocytogenes), and two tough-to-lyse yeasts (e.g.Saccharomyces cerevisiae). Seven of these strains are known human pathogens and have been fully inactivated with DNA/RNA Shield™ (Cat # 11-358). The GC content of the contained genomes covers a range from 15% to 85%. It was constructed by pooling pure cultures of the 10 microbial strains. The cells and DNA content of each pure culture were quantified before pooling. Cultures were mixed to a predetermined composition. The actual microbial composition was measured using Next-Generation sequencing techniques after extracting the genomic DNA with the ZymoBIOMICS™ DNA Mini Kit. The ZymoBIOMICS™ Microbial Community Standard was used to assess bias associated with several of the most cited methods for DNA extraction methods, and found that each suffered from over representation of easy-to-lyse gram negative organisms. The ZymoBIOMICS™ DNA Mini Kit was the only method that achieved unbiased isolation. Please click the links below for more detailed information.

Details regarding the ten microbial strains (including species name, genome size, ploidy, average GC content, 16S/18S copy number, phylogeny) can be found in Table 2 on the “more information” link below. The 16S/18S rRNA sequences (fasta format) and genomes (fasta format) of these strains are available upon request. Feel free to contact us if you need help analyzing the sequencing data generated from this standard.