A Modeled High-Density Fed-Batch Culture Improves Biomass Growth and β-Glucans Accumulation in Microchloropsis salina

Abstract

Algae and microalgae are used as a source of different biomolecules, such as lipids and carbohydrates. Among carbohydrates, polysaccharides, such as β-glucans, are important for their application as antioxidants, antisepsis, and immunomodulators. In the present work, the β-glucans production potential of Microchloropsis salina was assessed using two different culture conditions: a high-density batch and a modeled high-density fed-batch. From the biochemical parameters determined from these two cultures conditions, it was possible to establish that the modeled high-density fed-batch culture improves the biomass growth. It was possible to obtain a biomass productivity equal to 8.00 × 10−2 ± 2.00 × 10−3 g/(L × day), while the batch condition reached 5.13 × 10−2 ± 4.00 × 10−4 g/(L × day). The same phenomenon was observed when analyzing the β-glucans accumulation, reaching volumetric productivity equal to 5.96 × 10−3 ± 2.00 × 10−4 g of product/(L × day) against the 4.10 × 10−3 ± 2.00 × 10−4 g of product/(L × day) obtained in batch conditions. These data establish a baseline condition to optimize and significantly increase β-glucan productivity, as well as biomass, adding a new and productive source of this polymer, and integrating its use in potential applications in the human and animal nutraceutical industry.

LED Illumination Modules Enable Automated Photoautotrophic Cultivation of Microalgae in Parallel Milliliter-Scale Stirred-Tank Bioreactors

“…M. salina strains, media, illuminated layer thickness, and reactor types were found to vary considerably, making direct comparison difficult. Optimum growth rates of M. salina are reported between 0.1 and 1.3 d −1[17,[69][70][71][72]. The maximum OD750 measured in the stirred-tank PBRs is comparable to data published by Pfaffinger et al[30] reporting on photoautotrophic batch cultivations of M. salina using a flat plate gas-lift PBR on a literscale with a layer thickness of 2 cm.…”