Continuous extraction and application potential of value-added products from a promising microalga Coelastrella sp. SDEC-28 for green microalgae-based industry

Microalgae are emerging as a good source of various high-value bio-active compounds and nowadays are applied in several fields. Here we proposed a new extraction method, continuous extraction, to attain crude polysaccharides (CP), methanol extracts (ME) and crude lipid (CL) of a newly isolated soil microalgae, Coelastrella sp. SDEC-28, which improved the yield (amount to 40.60%, by dry weight) and application potential of these products simultaneously. The CP (at 2 mg/mL) from SDEC-28 showed the better antioxidant activity with 96.17% scavenging rates on 2, 2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical. ME extracted from continuous extraction displayed potent anti-proliferative effects on melanoma cancer cells A375, and the inhibition efficiency was up to 99.62% at high dose (1000 μg/mL) after 24 h exposure. The proportion of neutral lipid in CL obtained from continuous extraction was 1.38 times higher than that of one-step extraction. These results suggest that continuous extraction assists to fully utilize microalgal biomass and makes microalgae-based products industry more sustainable and greener for the future development.