Fig. 9.

Effect of database size on the number of modern metagenomic reads uniquely mapped to Yersinia pestis CO92 reference genome. Starting with Y. pestis alone, ~ 22,000 reads map uniquely. This number gradually decreases down to only a few reads with the growth of the database, i.e., when the human hg38 reference genome is added, followed by adding 10, 100, 1000, and 10,000 random bacteria, and finally, all available 28898 bacteria from the NCBI RefSeq database. The axes of the plot are log10-scaled