Growth-promoting bacteria double eicosapentaenoic acid yield in microalgae

Bingli Liu; Eladl E Eltanahy; Hongwei Liu; Elvis T Chua; Skye R Thomas-Hall; Taylor J Wass; Kehou Pan; Peer M Schenk

doi:10.1016/j.biortech.2020.123916

Growth-promoting bacteria double eicosapentaenoic acid yield in microalgae

Bioresour Technol. 2020 Nov:316:123916. doi: 10.1016/j.biortech.2020.123916. Epub 2020 Jul 31.

Authors

Bingli Liu¹, Eladl E Eltanahy², Hongwei Liu³, Elvis T Chua⁴, Skye R Thomas-Hall⁴, Taylor J Wass⁴, Kehou Pan⁵, Peer M Schenk⁶

Affiliations

¹ Laboratory of Applied Microalgae Biology, Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; Algae Biotechnology Laboratory, School of Agriculture and Food Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia.
² Algae Biotechnology Laboratory, School of Agriculture and Food Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia; Phycology Laboratory, Botany Department, Faculty of Science, Mansoura University, Mansoura 35516, Egypt.
³ Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales 2751, Australia.
⁴ Algae Biotechnology Laboratory, School of Agriculture and Food Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia.
⁵ Laboratory of Applied Microalgae Biology, Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China.
⁶ Algae Biotechnology Laboratory, School of Agriculture and Food Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia. Electronic address: p.schenk@uq.edu.au.

PMID: 32768998
DOI: 10.1016/j.biortech.2020.123916

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 × 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.

Keywords: Microbiome engineering; Nannochloropsis; Omega-3 fatty acid; Phycosphere; Probiotic bacteria.

MeSH terms

Bacteria
Biomass
Eicosapentaenoic Acid
Microalgae*
Stramenopiles*

Substances

Eicosapentaenoic Acid