We usually think of genetic differences in the context of human genetics. And so we are familiar with the fact that two people differ on average at about five million sites in the genome – that is, at only about 0.8 per cent of the entire genome. But genetic variation in bacteria has a completely different dimension: For example, two strains of Escherichia coli can differ in up to 60 percent of their genetic content.
This means that each bacterial species has not only a single genome, but also a diverse ensemble of gene combinations called a pangenome. We want to investigate the influence of this great genetic diversity on bacterial phenotypes.