Growth parameter estimation and model simulation for three industrially relevant microalgae: Picochlorum, Nannochloropsis, and Neochloris

Abstract

Multiple models have been developed in the field to simulate growth and product accumulation of microalgal cultures. These models heavily depend on the accurate estimation of growth parameters. In this paper growth parameters are presented for three industrially relevant microalgae species: Nannochloropsis sp., Neochloris oleoabundans, and Picochlorum sp. (BPE23). Dedicated growth experiments were done in photobioreactors to determine the maximal biomass yield on light and maintenance rate, while oxygen evolution experiments were performed to estimate the maximal specific growth rate. Picochlorum sp. exhibited the highest specific growth rate of 4.98 ± 0.24 day ⁻¹ and the lowest specific maintenance rate of 0.079 day ⁻¹, whereas N. oleoabundans showed the highest biomass yield on light of 1.78 g _x·mol _ph ⁻¹. The measured growth parameters were used in a simple kinetic growth model for verification. When simulating growth under light conditions as found at Bonaire (12 °N, 68° W), Picochlorum sp. displayed the highest areal biomass productivity of 32.2 g.m ⁻²·day ⁻¹ and photosynthetic efficiency of 2.8%. The presented growth parameters show to be accurate compared to experimental data and can be used for model calibration by scientists and industrial communities in the field.

Abstract

The growth parameters: maximal biomass yield on light, maintenance rate, and maximal specific growth rate were estimated through dedicated laboratory experiments for three industrially relevant microalgal species: Picochlorum, Nannochloropsis, and Neochloris. The estimated growth parameters were then used in a growth model to simulate biomass productivity at an industrial scale. Other scientists can use the estimated growth parameters as input data in their models.