Lab-Scale Optimization of Aurantiochytrium sp. Culture Medium for Improved Growth and DHA Production

Mafalda Trovão,Adriana Machado,João Varela,Maria Soares,Bernardo Carvalho,Hugo Pereira,Ana Barros,Margarida Costa,Joana Silva

doi:10.3390/app10072500

Mafalda Trovão, Adriana Machado + Show 7 more

Open Access

https://doi.org/10.3390/app10072500

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Journal: Applied sciences	Publication Date: Apr 5, 2020
Citations: 13	License type: CC BY 4.0

Affiliation: University of Algarve

Abstract

Thraustochytrids have gained increasing relevance over the last decades, due to their fast growth and outstanding capacity to accumulate polyunsaturated fatty acids (PUFAs), particularly docosahexaenoic acid (DHA). In this context, the present work aimed to optimize the growth performance and DHA yields by improving the culture medium of Aurantiochytrium sp. AF0043. Accordingly, two distinct culture media were optimized: (i) an inorganic optimized medium (IOM), containing only monosodium glutamate and glucose as nitrogen and carbon sources, respectively; and (ii) an organic and sustainable waste-based optimized medium (WOM), containing corn steep powder and glycerol, added in fed-batch mode, as nitrogen and carbon sources, respectively. Overall, the lab-scale optimization allowed to increase the biomass yield 1.5-fold and enhance DHA content 1.7-fold using IOM. Moreover, WOM enabled a 2-fold increase in biomass yield and a significant improvement in lipid contents, from 22.78% to 31.14%. However, DHA content was enhanced almost 3-fold, from an initial content of 10.12% to 29.66% of total fatty acids contained in the biomass. Therefore, these results strongly suggest, not only that the production pipeline was significantly improved but also confirmed the potential use of Aurantiochytrium sp. AF0043 as a source of DHA.

Highlights

IntroductionThraustochytrids are unicellular eukaryotic protists belonging to the superphylum Heterokonta ( known as Stramenopiles) and to the heterotrophic phylum Bigyra and the class Labyrinthulea [1]
Thraustochytrids are unicellular eukaryotic protists belonging to the superphylum Heterokonta and to the heterotrophic phylum Bigyra and the class Labyrinthulea [1]
Thraustochytrids are associated with a wide range of biotechnological applications, which triggered their industrial production for different high-value markets [2,3,4]

Summary

Introduction

Thraustochytrids are unicellular eukaryotic protists belonging to the superphylum Heterokonta ( known as Stramenopiles) and to the heterotrophic phylum Bigyra and the class Labyrinthulea [1]. Thraustochytrids are associated with a wide range of biotechnological applications, which triggered their industrial production for different high-value markets [2,3,4]. From a biotechnological point of view, two main features are responsible for the increasing interest in this family of microorganisms. They display high growth performance, reaching very high cell concentrations in a few days, and exhibit the striking ability to produce and accumulate docosahexaenoic acid (DHA) [4,5,6]. In contrast with the majority of microorganisms that produce saturated fatty acids (FA) as energy storage lipids, thraustochytrids synthesize long chain-polyunsaturated fatty acids (LC-PUFAs), like DHA, as energy storage, by an alternative pathway catalyzed by the polyketide synthase (PKS).

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