TY - JOUR
T1 - Growth-promoting bacteria double eicosapentaenoic acid yield in microalgae
AU - Liu, Bingli
AU - Eltanahy, Eladl E.
AU - Liu, Hongwei
AU - Chua, Elvis T.
AU - Thomas-Hall, Skye R.
AU - Wass, Taylor J.
AU - Pan, Kehou
AU - Schenk, Peer M.
PY - 2020
Y1 - 2020
N2 - 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 x 108 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.
AB - 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 x 108 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.
KW - bacteria
KW - microalgae
KW - microbial genetic engineering
KW - probiotics
UR - https://hdl.handle.net/1959.7/uws:59018
U2 - 10.1016/j.biortech.2020.123916
DO - 10.1016/j.biortech.2020.123916
M3 - Article
SN - 0960-8524
VL - 316
JO - Bioresource Technology
JF - Bioresource Technology
M1 - 123916
ER -