Fig. 2

Complementation of uracil auxotrophy of S. cerevisiae ura1Δ strains by expression of heterologous URA9 orthologs. The native ScURA1 gene of S. cerevisiae was replaced by URA9 orthologs from K. marxianus (Km), O. parapolymorpha (Op), A. robustus (Ar), D. bruxellensis (Db) or Sch. japonicus (Sj). A Aerobic cultures, B: anaerobic cultures. Open bars indicate specific growth rates (μ) on synthetic medium without uracil (SMUD), closed bars indicate μ in uracil-supplemented synthetic medium (SMUD + ura). Relevant genotypes of S. cerevisiae strains: CEN.PK113-7D, ScURA1 reference strain; IMK824, ura1Δ reference strain; IMI446, ura1Δ::KmURA9; IMI447, ura1Δ::OpURA9; IMI432, ura1Δ::Arura9; IMI439, ura1Δ::DbURA9; IMI452, ura1Δ::SjURA9. *Since strain IMI439 (ura1Δ::DbURA9) showed delayed growth in initial anaerobic cultures on SMUD, its specific growth rate on SMUD was measured after transfer to a second culture. Data represent the average from biological duplicates and mean deviation (Additional file 5; Table S1)