What this work is about, in plain words
A method that in 2–4 hours determines dry weight, pigments, protein, carbohydrates and lipids in a single microalgae sample, saving time and reagents.
To understand how biomass composition changes during cultivation, it needs to be measured often. Conventional methods determine one component at a time and take a long time. In continuous-flow cultivation, when part of the culture is withdrawn every few hours, this becomes a serious problem. The authors set out to develop a combined method that determines the main components of biomass in a short time.
All stages of the method are based on measuring the color of solutions on a common laboratory photocolorimeter. The analyses are performed in sequence on one sample: first pigments, then other components.
According to the authors, in 2–4 hours the method gives dry weight and the content of chlorophyll, carotenoids, total protein, carbohydrates and lipids. The error is 4 to 6 % depending on the component. The method was tested on cultures of six species from different groups: spirulina, Porphyridium, chlorella, Dunaliella, Tetraselmis and the cyanobacterium Synechococcus. The authors warn that the stages affect each other: for example, prior extraction of pigments overestimates the protein result, so cross-checking against standard methods is needed.
The work is useful for laboratories that monitor culture composition over time.
Limitations. This is a methods paper. For a new species, the method needs to be checked against standard analyses.