Trade-off between interspecific competitive ability and growth rate in bacteria

Bacteria from aquatic microcosms were subjected to serial transfer at 12-h and 3-d intervals in single- and two-species cultures. Selection in single-species populations under serial transfer at 3-d intervals favored an increased growth rate. In mixed culture, serial transfer at 3-d intervals led to coexistence of the two species, and resulted in the r values of both species undergoing slight reductions or remaining unchanged in comparison to the parental strain; serial transfer at 12-h intervals led to extinction of the species with lower r. Results can be viewed as evidence for a trade-off between interspecific competitive ability and growth rate. -from Authors