What this work is about, in plain words
Measuring lipids in biomass is slow and laborious. The authors found that in the diatom Cylindrotheca closterium lipid content is linearly related to the content of the pigment fucoxanthin, which is easier to measure.
The diatom Cylindrotheca closterium accumulates two valuable products: the pigment fucoxanthin and lipids with polyunsaturated fatty acids. To tune cultivation conditions for lipids, their content needs to be monitored quickly. Classical lipid analysis is too slow for this. The authors checked whether lipids can be judged from fucoxanthin.
The culture was grown under different conditions: in batches and in continuous-flow mode. Fucoxanthin, total lipids and fatty acid composition were measured in the biomass.
According to the authors, the content of fucoxanthin and total lipids is linearly related under all the cultivation conditions studied. The biomass contained up to 2.3 % fucoxanthin by dry weight. Among the fatty acids, eicosapentaenoic and arachidonic acids stand out: up to 4.3 % and 1.5 % of dry weight.
A rapid method can be built on this relationship: measure the pigment, estimate the lipids. This helps to understand quickly in which mode the culture accumulates more of the substances needed.
Limitations. This is a short article: the relationship was found for one species under laboratory conditions, and the authors propose developing the rapid method itself on this basis. The fucoxanthin figures in the abstract and the conclusion of the article differ (up to 2.3 % and up to 10 mg per gram), which probably reflects different experimental conditions.