Whole genome sequencing of colonies derived from cannabis flowers and the impact of media selection on benchmarking total yeast and mold detection tools

We performed whole genome sequencing to assess the specificity of colony forming units derived from three different plating media’s: Potato Dextrose Agar (PDA), PDA with chloramphenicol and Dichloran Rose Bengal with chloramphenicol (DRBC). Colonies were isolated from each media type and whole genome sequenced to identify the diversity of microbes presented with each media selection. ITS3 and 16S qPCR was performed to correlate these CFUs with fungi and bacterial specific qPCR. The plating mediums each displayed a log scale different colony forming unit count. PDA with chloramphenicol demonstrated the highest diversity and the highest concordance with whole genome sequencing. According to ITS3 and 16S qPCR DRBC under counts yeast and mold while PDA without chloramphenicol over counts CFUs due to bacterial growth without selection.