Isolation, Identification and Biotechnological Applications of a Novel, Robust, Free-living <i>Chlorococcum (Oophila) amblystomatis</i> Strain Isolated from a Local Pond

• Main Authors: Nádia Correia, Hugo Pereira, Joana T. Silva, Tamára Santos, Maria Soares, Carolina B. Sousa, Lisa M. Schüler, Margarida Costa, João Varela, Leonel Pereira, Joana Silva
• Format: Article
• Language: English
• Published: MDPI AG 2020-04-01
• Series: Applied Sciences
• Subjects: bioprospection; microalgae; <i>Chlorococcum (Oophila) amblystomatis</i>; photobioreactors; industrial-scale production; biotechnological applications
• Online Access: https://www.mdpi.com/2076-3417/10/9/3040

Bioprospection of novel autochthonous strains is key to the successful industrial-scale production of microalgal biomass. A novel <i>Chlorococcum</i> strain was recently isolated from a pond inside the industrial production facility of Allmicroalgae (Leiria, Portugal). Phylogenetic analysis based on 18S ribosomal ribonucleic acid (rRNA) gene sequences suggests that this isolate is a novel, free-living <i>Oophila amblystomatis</i> strain. However, as our phylogenetic data strongly suggests that the aforementioned taxon belongs to the genus <i>Chlorococcum,</i> it is here proposed to rename this species as <i>Chlorococcum amblystomatis</i>. In order to characterize the biotechnological potential of this novel isolate, growth performance and biochemical composition were evaluated from the pilot (2.5-m³) to industrial (10-m³) scale. The highest maximum areal productivity (36.56 g·m⁻²·day⁻¹) was reached in a 10-m³ tubular photobioreactor (PBR), as compared to that obtained in a 2.5-m³ PBR (26.75 g·m⁻²·day⁻¹). <i>Chlorococcum amblystomatis</i> displayed high protein content (48%–56% dry weight (DW)) and moderate levels of total lipids (18%–31% DW), carbohydrates (6%–18% DW) and ashes (9%–16% DW). Furthermore, the lipid profile was dominated by polyunsaturated fatty acids (PUFAs). The highest pigment contents were obtained in the 2.5-m³ PBR, where total chlorophylls accounted for 40.24 mg·g⁻¹ DW, followed by lutein with 5.37 mg·g⁻¹ DW. Overall, this free-living <i>Chlorococcum amblystomatis</i> strain shows great potential for nutritional applications, coupling a promising growth performance with a high protein content as well as relevant amounts of PUFAs, chlorophyll, and carotenoids.