Maintaining populations of microbial cells under controlled conditions of growth and environment for an indefinite duration is a prerequisite for experimentally evolving natural isolates of wild-type species or recombinant strains.

Continuous culture vessels called chemostats have been used since the 1950’s to select for cells that have a higher proliferation rate under given conditions (Monod J., 1950, Ann. Inst. Pasteur. 19:390-410 ; Novick A., Szilard L., 1950, Science 112:715-716). These work by partial dilution - as a culture grows and becomes saturated, a small proportion of the grown culture is replaced with fresh medium, allowing the culture to continually grow at close to its maximum population size.

The potential power of these devices was recognized, but they have never met that potential because they invariably select mutants that evade dilution through attachment to vessel surfaces, resulting in persistent sub-populations of uncontrollable size and growth rate (wall growth). This wall growth selection prevents selection of the targeted characteristics of the researched micro-organism.

The Evolugator eliminates wall growth problems and this would lead to many applications in the microbial field. Evolugate holds the exclusive and worldwide license under the patent rights claiming the continuous culture apparatus (Evolugator) and its use.