A comparative study on the genomes, transcriptomes, and metabolic properties of strains Nissle 1917, BL21(DE3), and MG1655.

is the most well-studied model prokaryote and has become an indispensable host for the biotechnological production of proteins and biochemicals. In particular, the probiotic status of one Nissle 1917 (EcN) has helped it become a new favorite amongst synthetic biologists. To broaden its potential applications, here we assemble a comparative study on the genomes, transcriptomes, and metabolic properties of strains EcN, BL21(DE3), and MG1655. Comparative genomics data suggests that EcN possesses 1404 unique CDSs. In particular, EcN has additional iron transport systems which endow EcN with a higher tolerance to iron scarcity when compared to two other strains. EcN transcriptome data demonstrates that strains EcN, BL21(DE3), and MG1655 all have comparable activities of the central metabolic pathway, however only EcN inherits the arginine deiminase pathway. Additionally, we found that EcN displayed a lower expression of ribosomal proteins compared to BL21(DE3) and MG1655. This comparative study on strains EcN, BL21(DE3), and MG1655 aims to provide a reference for further engineering EcN as a biotechnological tool.