Evaluation of the potential of Chlorella sp. HS2, an algal isolate from a tidal rock pool, as an industrial algal crop under a wide range of abiotic conditions

• Published in: Journal of applied phycology 2019-08, Vol.31 (4), p.2245-2258
• Main Authors: Yun, Jin-Ho, Cho, Dae-Hyun, Heo, Jina, Lee, Yong Jae, Lee, Bongsoo, Chang, Yong Keun, Kim, Hee-Sik
• Format: Article
• Language: English
• Subjects: Algae; Algal growth; Bicarbonates; Biochemical composition; Biomass; Biomedical and Life Sciences; Biomolecules; Carbon dioxide; Carbon sources; Carotene; Carotenoids; Chlorella; Coastal waters; Crops; Cultivation; Ecology; Esters; Evaluation; Fatty acid methyl esters; Fatty acids; Flue gas; Freshwater & Marine Ecology; Growth rate; Life Sciences; Lutein; Microalgae culture; Microbiological strains; Mixotrophy; Organic carbon; Palmitic acid; pH effects; Plant Physiology; Plant Sciences; Rocks; Salinity; Salinity effects; Sodium; Sodium bicarbonate; Sodium chloride; Supplements; Temperature; Temperature effects; Wastewater; Wastewater treatment
• ISSN: 0921-8971; 1573-5176
• DOI: 10.1007/s10811-019-1751-z

While the screening and development of robust algal crops have mostly focused on determining strains that exhibit the highest possible yields of biomass or desirable biomolecules, these criteria do not necessarily lead to finding algal strains with high tolerance to varying outdoor cultivation conditions. Herein, we report Chlorella sp. HS2 isolated from a tidal rock pool nearby a local coastal waterfall that presumably experienced fluctuations in salinity, pH, and temperature. Compared to two reference strains, Chlorella sp. HS2 exhibited relatively high tolerance to a wide range of salinity (0–5% ( w / v ) of supplemental NaCl), pH (3.0–10.5), and temperature (14–46 °C) with substantially high biomass accumulation. While the supplementation of either gaseous CO 2 or sodium bicarbonate enhanced algal growth, the mixotrophic and heterotrophic cultivations of Chlorella sp. HS2 further indicated its propensity to grow favorably under the presence of organic carbon sources. Subsequent PBR cultivation of Chlorella sp. HS2 under optimal light and/or temperature conditions suggested the highest specific growth rate during mixotrophy, while the analyses of the harvested biomass identified palmitate, oleate, and linoleate as major fatty acid methyl esters, and lutein and ß-carotene as predominant carotenoids. Substantially, high growth rates of Chlorella sp. HS2 under a wide range of abiotic conditions and different trophic modes with favorable biochemical composition thus strongly support our algal isolate as a robust and reliable algal crop that can be deployed to achieve high production of commercially important biomolecules and to incorporate simultaneous treatment of wastewater or CO 2 -replete flue gas into algal cultivation.