What this work is about, in plain words
A mathematical model of the growth of a microalgae culture that lacks one of its nutrients. It gives a formula for the whole growth curve and simplifies the processing of experimental data.
The main characteristic of culture growth is its growth curve: how density changes from inoculation until growth stops. The shape of this curve shows what limits growth at each stage. For this, the data must be processed mathematically in a correct way. Classical models are borrowed from enzyme kinetics and do not take into account that cells constantly lose part of their biomass. The authors set out to build a model of culture growth limited by one mineral substance that accounts for these losses.
The model assumes that the observed growth is the difference between the formation of biomass and its losses: to division, release of substances into the medium, and respiration in the dark. The dependence of growth rate on nutrient concentration is given by a simple broken line.
According to the authors, the dependences of productivity and specific growth rate on culture density were obtained, as well as a simple formula for the whole growth curve in the form of a hyperbolic tangent. The main advantage of the model is that it has an exact analytical solution, which noticeably simplifies the processing of experimental data.
The work gives researchers a convenient tool for analyzing experiments with algae cultures.
Limitations. This is a theoretical work. The model describes the case in which growth is limited by one substance and the medium is not renewed.