Adaptively evolved yeast mutants on galactose show trade-offs in carbon utilization on glucose

• Adaptive evolution offers many opportunities in metabolic engineering; however, several constraints still exist as evolutionary trade-offs may impose collateral cost to obtain new traits. The application of adaptive evolution for strains development could be further improved by elucidating the molecular mechanisms. In this study, adaptively evolved yeast mutants with improved galactose utilization ability showed impaired glucose utilization. The molecular genetic basis of this trade-off was investigated using a systems biology approach. Transcriptional and metabolic changes resulting from the improvement of galactose utilization were found maintained during growth on glucose. Moreover, glucose repression related genes showed conserved expression patterns during growth on both sugars. Mutations in the RAS2 gene that were identified as beneficial for galactose utilization in evolved mutants exhibited significant correlation with attenuation of glucose utilization. These results indicate that antagonistic pleiotropy is the dominant mechanism in the observed trade-off, and it is likely realized by changes in glucose signaling.

Subject headings

NATURVETENSKAP  -- Kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences (hsv//eng)

Keyword

adaptation

Systems biology

saccharomyces-cerevisiae

escherichia-coli

Metabolic engineering

Galactose metabolism

evolution

Evolutionary trade-off

populations

Glucose

Publication and Content Type

art (subject category)

ref (subject category)