Media optimization design towards maximizing biomass production of Tetradesmus obliquus under mixotrophic conditions

https://doi.org/10.1016/j.biteb.2021.100885Get rights and content

Highlights

Maximizing mixotrophic biomass production of Tetradesmus obliquus microalgae

Finding an optimal composition of the culture medium for biomass production

Design of experiment application using the Taguchi orthogonal array

Studying the effect of eight important nutrients and their interaction on biomass

Using analysis of variance as a statistical tool to analyze the results

Abstract

Maximizing biomass production is a key factor in developing large-scale microalgae cultivation. One major aspect to address is the cultivation medium composition in regards to the process objective. In this study, the effect of eight important nutrients/factors (glucose, nitrate, phosphate, sulfate, magnesium, iron, manganese, and calcium) and their interactions were investigated on the biomass production of the microalgae Tetradesmus obliquus under mixotrophic conditions. The Taguchi method, a robust tool for experimental design optimization, was used to find the optimum media composition for biomass production, with only a few well-defined experimental sets. Using Taguchi's L18 orthogonal array resulted to a 4-fold enhancement in biomass yields, with a maximum of about 7.98 g/L. Nitrate exhibited the most significant effect. Iron and phosphate showed a strong influence on short-term cultivations (6 to 9 days), while glucose and calcium had more impact on long-term cultivations (15 days). The overall optimum experimental conditions were provided.

Keywords

Microalgae
Biomass production
Taguchi method
Medium composition optimization
Mixotrophic production
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