Growth-promoting bacteria double eicosapentaenoic acid yield in microalgae. (November 2020)

• Record Type: Journal Article
• Authors: Liu, Bingli; Eltanahy, Eladl E.; Liu, Hongwei; Chua, Elvis T.; Thomas-Hall, Skye R.; Wass, Taylor J.; Pan, Kehou; Schenk, Peer M.
• Is Part Of: Bioresource technology. Volume 316(2020)
• Publication Date: 2020-11
• Subjects: Microbiome engineering -- Nannochloropsis -- Omega-3 fatty acid -- Phycosphere -- Probiotic bacteria; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2020.123916
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: 33 bacterial strains were isolated from the phycosphere of Nannochloropsis oceanica. Co-cultivation of N. oceanica with ten bacterial strains improved algal growth. Seven strains also significantly increased omega-3 EPA biosynthesis and yields. Bacterial community profiling revealed significantly-altered phycosphere microbiomes. Over 2-fold increases in microalgal culture density and EPA yields were achieved. Abstract: High-yielding microalgae present an important commodity to sustainably satisfy burgeoning food, feed and biofuel demands. Because algae-associated bacteria can significantly enhance or reduce yields, we isolated, identified and selected highly-effective "probiotic" bacterial strains associated with Nannochloropsis oceanica, a high-yielding microalga rich in eicosapentaenoic acid (EPA). Xenic algae growth was significantly enhanced by co-cultivation with ten isolated bacteria that improved culture density and biomass by 2.2- and 1.56-fold, respectively (1.39 × 10 8 cells mL −1 ; 0.82 g L −1 ). EPA contents increased up to 2.25-fold (to 39.68% of total fatty acids). Added probiotic bacteria possessed multiple growth-stimulating characteristics, including atmospheric nitrogen fixation, growth hormone production and phosphorous solubilization. Core N. oceanica -dominant bacterial microbiomes at different cultivation scales included Sphingobacteria, Flavobacteria (Bacteroidetes), and α, γ-Proteobacteria, and added probiotic bacteria could be maintained. We conclude that the supplementation with probiotic algae-associated bacteria can significantly enhance biomass and EPA production of N. oceanica .