What this work is about, in plain words
What happens to algal pigments when the cell stops making them because of a lack of nitrogen while light keeps destroying them? The author described this process with equations.
The amount of pigment in an algal cell is set by two opposing processes: synthesis and destruction by light. During normal growth they run simultaneously and cannot be separated. Earlier in this series, the authors considered the case in which these processes are balanced. Here the other extreme is considered: when synthesis has stopped completely, for example because of a severe lack of nitrogen, and only destruction remains.
The work is theoretical. The author solved a system of equations describing the photodestruction of pigments and built a model of how their content changes over time when synthesis has stopped.
According to the author, the equations were applied to experimental data for the red alga Porphyridium cruentum and the cyanobacterium Oscillatoria under deep nitrogen starvation and describe the dynamics of their pigments.
The work helps to understand how fast a culture loses pigments in light when nutrients are lacking. This matters when pigments are the target product.
Limitations. The model describes the extreme case in which pigment synthesis has stopped completely. It was tested on two species. The text of the article is available only as a scan; the explanation was written from the recognized text.