A Fast-Growing Oleaginous Strain of Coelastrella Capable of Astaxanthin and Canthaxanthin Accumulation in Phototrophy and Heterotrophy

Abstract

Considering the importance of microalgae as a promising feedstock for the production of both low- and high-value products, such as lipids and pigments, it is desirable to isolate strains which simultaneously accumulate these two types of products and grow in various conditions in order to widen their biotechnological applicability. A novel freshwater strain from the genus Coelastrella was isolated in Belgium. Compared to other Coelastrella species, the isolate presented rapid growth in phototrophy, dividing 3.5 times per day at a light intensity of 400 µmol·m−2·s−1 and 5% CO2. In addition, nitrogen depletion was associated with the accumulation of astaxanthin, canthaxanthin, and fatty acids, which reached ~30% of dry weight, and a majority of SFAs and MUFAs, which are good precursors for biodiesel. This strain also accumulated astaxanthin and canthaxanthin in heterotrophy. Although the content was very low in this latter condition, it is an interesting feature considering the biotechnological potential of the microalgal heterotrophic growth. Thus, due to its rapid growth in the light, its carotenogenesis, and its fatty acids characteristics, the newly identified Coelastrella strain could be considered as a potential candidate for biorefinery purposes of both low- and high-values products.

Formation of Lutein, β-Carotene and Astaxanthin in a Coelastrella sp. Isolate

“…The surface topology of the cells was visible in SEM images, the cells exhibiting meridional ribs that run from one pole to the other ( Figure 1 d). These features have been described for other Coelastrella species and are evidently typical of the genus [ 18 , 20 , 21 , 23 , 24 ].…”

“…KGU-H001 [ 16 ], Coelastrella terrestris [ 17 ], Coelastrella astaxanthina sp. nov. [ 18 ], as well as several other Coelastrella isolates [ 19 , 20 , 21 ]. Indeed, it has been suggested that Coelastrella could be a viable candidate for commercial production of carotenoids.…”

Growth characterization and biostimulant potential ofCoelastrellasp. D14 a green microalga isolated from a solar panel

“…In the conditions tested, D14 displayed a doubling time of 2.6 days (Table S1). A novel freshwater Coelastrella strain isolated in Belgium, presented a rapid growth in phototrophy, with a doubling-time of 6.8 ± 0.30 h hours at a light intensity of 400 µmol·m −2 ·s −1 and 5% CO 2 (Corato et al, 2022). The specific growth rate seems to depend on dosing times of the carbonic solution added to the culture unless indoor.…”

Cell adaptation of the extremophilic red microalga Galdieria sulphuraria to the availability of carbon sources

“…Glass beads were added to the sample and cells were disrupted through horizontal agitation in a TissueLyser II (Qiagen, Hilden, Germany) for 2 × 5 min at 30 Hz. Fatty Acid Methyl Esters (FAMEs) were generated from the microalgal biomass as described in Corato et al (2022) . FAMEs quantification was performed using gas chromatography (GC, Shimadzu, Tokyo, Japan) and a flame ionization detector (FID, Shimadzu) as mentioned in Gérin et al (2020) .…”