Co-cultivation of Phaeodactylum tricornutum and Aurantiochytrium limacinum for polyunsaturated omega-3 fatty acids production

• Published in: Bioresource technology 2022-02, Vol.346, p.126544-126544, Article 126544
• Main Authors: Kadalag, Nikhil L., Pawar, Pratik R., Prakash, Gunjan
• Format: Article
• Language: English
• Subjects: Co-culture; Diatom; Diatoms; Docosahexaenoic acid; Docosahexaenoic Acids; Eicosapentaenoic Acid; Fatty Acids; Fatty Acids, Omega-3; Fatty Acids, Unsaturated; Stramenopiles; Thraustochytrid
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2021.126544

[Display omitted] •Co-cultivation of P. tricornutum and A. limacinum for desired EPA:DHA ratio.•Initial cell density optimization was crucial for co-cultivation of both species.•Nitrate acted as limiting nutrient during co-cultivation.•Fed-batch resulted in 2:1 and 1:1 EPA:DHA ratio depending upon C:N ratio.•First report of diatom and thraustochytrids co-cultivation for EPA:DHA ratio modulation. Marine protist Aurantiochytrium limacinum produces docosahexaenoic acid (DHA) as main polyunsaturated fatty acid (PUFA) and lacks any monounsaturated fatty acids (MUFA), while eicosapentaenoic acid (EPA) and MUFA’s are produced by Phaeodactylum tricornutum. The marine diatom P. tricornutum was co-cultured with A.limacinum to match the EPA:DHA ratio of fish oil. Modulation in initial cell density ratio overcame the dominance of A.limacinum during co-cultivation and led to regulated proliferation of both species. Media engineering with nitrate and glycerol concentration yielded 2:1 (56.44: 30.11) mg g−1 and 1:1 (47.43: 49.61) mg g−1 EPA: DHA ratio. The oil and biomass obtained from co-cultivation comprised of MUFA’s such as palmitoleic acid (2.65 mg g−1) and oleic acid (1.25 mg g−1) along with pigments like fucoxanthin (367.18 µg g−1), β-carotene (8.98 µg g−1) and astaxanthin (0.77 µg g−1). Thus, co-cultivation of P. tricornutum with A. limacinum represented a unique strategy towards achieving desired fatty acid composition.