Pleiotropic effects of adaptation to a single carbon source for growth on alternative substrates

The capacity of growing bacteria populations to adapt from one carbon source for growth on alternative substrates has been investigated. The bacteria strains used in the study are two natural isolates of beta-proteobacteria that can degrade the herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D). Twenty lineages of bacteria were allowed to evolve with succinate as the sole carbon source and 2,4-D as the limiting substrate during experimental evolution. Results reveal that only three derived lines had a clear drop in fitness on the alternate substrate after adaptation to their selective substrate. Five derived lines showed improved fitness on both substrates.