Metagenomic peek into a corn mummy

Abstract

Numerous studies have shown that metagenomics has opened up a new dimension in reading the contents of archaeological remains as time capsules. Corn mummies are ritual objects made in ancient Egypt by forming human-shaped figures made of cereal grains grown in a mixture of water and earth. We performed metagenomic analyses on samples from a corn mummy dated to the second half of the 3rd century BC. Alongside a number of clearly modern contaminants, we identified organisms that cannot be excluded as being of historical origin. Besides considerable amounts of bacterial sequences belonging to the genera Bacillus, Coprococcus, Metabacillus, Niallia and Roseburia, we also found traces of plants, animals, and humans. Sequences assigned to the genus Triticum showed the highest similarity to ancient T. turgidum ssp. dicoccum specimens from Egypt and the southern Levant. Sequences classified in the genus Populus showed the highest identity with the genome of P. nigra. The fragments that were identified as being of Lepidopteran origin showed the greatest similarity to the genomes of the Sphingidae. Haplotype analysis of H. sapiens sequences suggests haplogroups L3 and E, based on the mitogenome and Y chromosome, respectively, which are the two common lineages in sub-Saharan Africa today.