If we start with equal initial concentration of biomass in terms of dry weight then which algal strain will give highest biomass concentration after 4 days (exponential period). Which one among them is fastest growing?
I assume you refer to the maximal biomass concentration and not to the biomass productivity or biomass yield on light. This would depend on what becomes limiting (first). For instance,
1) When light intensity becomes limiting (for instance at very low light), the biomass-specific maintenance energy requirement will determine the maximal biomass concentration that is reached. Published maintenance requirements of microalgae are not very abundant, but see for instance the paper by Kliphuis and Klok et al (attached).
2) When the nutrients become limiting first (so in case of enough supply of carbon and light, and at controlled pH), it largely depends on the cellular nutrient contents and on how efficient photosynthesis stays after nutrient depletion. The cellular nitrogen content is around 7-10% of dry weight for most microalgae during balanced growth conditions. For phosphorous this is around 0.5-1.5% (excluding luxury consumption). Therefore, I do not expect much difference in the biomass concentration at the moment of N or P runout for the species you mention. The largest changes will occur after that. As far as I know the final biomass densities reached after N or P depletion have not been extensively studied for all species you mention, but as an example: some species may still increase 8-fold in biomass once extracellular nitrogen becomes zero (while Chlorella vulgaris only increases about 4-fold). See papers by breuer et al for observations on various microalgae and for mathematical description and implications for oil, starch and biomass production (attached).
Hope this helps,
Packo
I agree with Packo. Also, it will be important to determinate the biovolume of your strains.
@Packo P Lamers: thanks. yes i am asking for biomass concentration in BG 11 after exponential phase. pH 7.5, light intensity 37μmol photons m-2 s-1, light duration 14:10 in flasks plugged with cotton.Which one among them is fastest growing?
Interesting question: I would wright away set up an experiment to determine the growth rates of these algae under identical conditions (medium, light intensity, etc.).
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