Selection of Culture Conditions and Cell Morphology for Biocompatible Extraction of β-Carotene from Dunaliella salina.

Guillaume Tanguy,Luc Marchal,Aline Legat,Olivier Gonçalves,Benoît Schoefs

doi:10.3390/md19110648

Abstract

Biocompatible extraction emerges recently as a means to reduce costs of biotechnology processing of microalgae. In this frame, this study aimed at determining how specific culture conditions and the associated cell morphology impact the biocompatibility and the extraction yield of β-carotene from the green microalga Dunaliella salina using n-decane. The results highlight the relationship between the cell disruption yield and cell volume, the circularity and the relative abundance of naturally permeabilized cells. The disruption rate increased with both the cell volume and circularity. This was particularly obvious for volume and circularity exceeding 1500 µm3 and 0.7, respectively. The extraction of β-carotene was the most biocompatible with small (600 µm3) and circular cells (0.7) stressed in photobioreactor (30% of carotenoids recovery with 15% cell disruption). The naturally permeabilized cells were disrupted first; the remaining cells seems to follow a gradual permeabilization process: reversibility (up to 20 s) then irreversibility and cell disruption. This opens new carotenoid production schemes based on growing robust β-carotene enriched cells to ensure biocompatible extraction.

Highlights

Microalgae have been identified as promising sources for the production of biomolecules for energy, food, feed, health, pharmaceutical, and cosmetic industries [1]
It has been reported that lipid extraction from microalgae with organic solvent depends on the contact time and area between the culture media and the organic solvent, but the higher the extraction the lower the biocompatibility [11,14,16,17,18]
This study revealed that the culture conditions and the associated morphology of D. salina were important factors to be considered to drive the extraction of β-carotene with n-decane

Summary

Introduction

Microalgae have been identified as promising sources for the production of biomolecules for energy, food, feed, health, pharmaceutical, and cosmetic industries [1]. Current microalgal fractionation processes require several downstream steps such as dewatering, drying, solvent extraction and purification of the target biomolecules [5]. They generate residues that need to be treated. In situ extraction methods or milking have been proposed This can include the use of pre-treatments such as electric pulses [7,8], resonance frequency [9], or biocompatible solvents [10,11,12,13,14]. It has been reported that lipid extraction from microalgae with organic solvent depends on the contact time and area between the culture media and the organic solvent, but the higher the extraction the lower the biocompatibility [11,14,16,17,18]

Objectives

Methods

Findings

Conclusion