In this study we further investigate the previously observed syntrophic interaction between Geobacter sulfurreducens and Pseudomonas aeruginosa. In early coculture establishment, two genetic variants of G. sulfurreducens emerged that were strongly selected for throughout coculture evolution. Single nucleotide polymorphism (SNP) variants occurred in fabI and tetR genes of G. sulfurreducens. The tetR variants displayed upregulation of adenylate cyclase transporter, CyaE and of RND efflux pump proteins as determined through SWATH-MS proteomics.