Development of improved formulation for Neochloris oleoabundans via an automated microalgal nutrient screening system

Abstract

Microalgal biomass has been regarded as one of the most promising commodities for biofuels production, fertilisers, animal food and high-value products. The capacity to generate high microalgal biomass is hence crucial to increase the number of the product that can be derived microalgal biomass. Recently, an advanced high-throughput nutrient screen was used to optimise the nutrient formulation to maximise the growth of Neochloris oleoabundans under photoautotrophic condition. The screen was designed to optimise 10 nutrients via the Box-Behnken experimental design that established a screen comprising 180 media formulations matrix for microalgae cultivation (150 μL microplate-based miniature-scale cultivation system). Improved cultivation media were formulated for N. oleoabundans via the nutrient screening system. Medium formulation no. 51 and 76 (from the 180 media formulation) yielded the highest end-point OD560 of 1.319 ±0. 009 and 1.345 ±0. 023 respectively and both formulations were redesignated as medium M1 and M2 respectively for subsequent experiments. Reproducibility assessment of both media (1 L larger scale experiments) was in concordance with miniature scale data. Nutrient main effect statistical analysis suggested that modulation of Ca, Mg, Fe, Mn and Zn concentrations may further improve the N. oleoabundans growth performance.