Scaling up of native species for a sustainable microalgal biorefinery targeting different microalgal products

Abstract

The present study aims to establish a sustainable bio refinery production in a semi-outdoor environment using two different types of media; fertilizer-based medium (FBM) and wastewater based medium (WWBM). A comparative study was performed under laboratory conditions to evaluate the effects of these media on a smaller scale. Cultivation was further scaled up to 500 L volume using WWBM resulting in four folds more biomass accumulation, 1.3 folds more carbohydrate accumulation, and 1.2 folds more lipids compared to cultivation under laboratory conditions. In this study, the species Ettlia texensis was used. It was isolated from the nearby regions of Indore. Being indigenous, Ettlia texensis easily adapted to Indore's climatic conditions and produced important precursors without compromising biomass. With the supplementation of WWBM at 500 L cultivation volume, E. texensis was able to produce 493.4 ± 34.4 μg of lipid per mg of biomass, which was 1.5 folds higher than at the laboratory scale. This study facilitates successful up-scaling of the process by providing insight into the utilization of low-cost media for microalgal production. The semi-outdoor cultivation of E. texensis to produce precursors of various compounds is used in this study for the first time.