Understanding time-growth rate relationship for slow-growing microbial cells in retentostat culturing systems [Dataset]

Generally, microorganisms in nature are severely growth limited because of nutrient availability, competition or physico-chemical parameters. To simulate these growing conditions the use of continuous culturing systems have been proposed. One modification of these systems is the so called retentostat. It corresponds to a system closed to cells and open to nutrients and a nutrient is limiting growth. In this system, cells are forced to reduce progressively their growth rate as a result of increasing biomass sharing the same resources. In these systems near-zero growth rates (corresponding to long doubling times) can be achieved within relatively reasonable time frames. Nevertheless, in these systems the relationship between growth rate and time remains to be further analyzed. Herein, we evaluate a retentostat culturing system for different prokaryotic species. We established a general relationship between growth rate and incubation time. This allows to easily estimate either the growth rate reached after a given incubation time or the time required to obtain cells at a specific slow growth rate. Results suggested progressive adaptation of cells at decreasing growth rates. This contribution simplifies estimates for incubation time-depending growth rates and shows a retentostat as a species-independent culturing system where growth rates depend on time and dilution rate.