Production of Fatty Acids and Protein by Nannochloropsis in Flat-Plate Photobioreactors

PLoS One. 2017 Jan 19;12(1):e0170440. doi: 10.1371/journal.pone.0170440. eCollection 2017.

Abstract

Nannochloropsis is an industrially-promising microalga that may be cultivated for alternative sources of nutrition due to its high productivity, protein content and lipid composition. We studied the growth and biochemical profile of Nannochloropsis 211/78 (CCAP) in optimized flat-plate photobioreactors. Eighteen cultivations were performed at two nutrient concentrations. The fatty acid, protein content and calorific values were analyzed after 8, 12 and 16 days. Neutral lipids were separated and the changes in fatty acids in triglycerides (TAGs) during nutrient depletion were recorded. The maximum cell density reached 4.7 g∙L-1 and the maximum productivity was 0.51 g∙L-1∙d-1. During nutrient-replete conditions, eicosapentaneoic acid (EPA) and total protein concentrations measured 4.2-4.9% and 50-55% of the dry mass, respectively. Nutrient starvation induced the accumulation of fatty acids up to 28.3% of the cell dry weight, largely due to the incorporation of C16:0 and C16:1n-7 fatty acyl chains into neutral lipids. During nutrient starvation the total EPA content did not detectibly change, but up to 37% was transferred from polar membrane lipids to the neutral lipid fraction.

MeSH terms

  • Algal Proteins / biosynthesis*
  • Biomass
  • Culture Media
  • Eicosapentaenoic Acid / biosynthesis
  • Equipment Design
  • Fatty Acids / biosynthesis*
  • Microalgae / cytology
  • Microalgae / growth & development
  • Microalgae / metabolism
  • Photobioreactors*
  • Stramenopiles / cytology
  • Stramenopiles / growth & development
  • Stramenopiles / metabolism*

Substances

  • Algal Proteins
  • Culture Media
  • Fatty Acids
  • Eicosapentaenoic Acid

Grants and funding

Funding was received by Nordland County Government, Norway, as part of the project ‘Bioteknologi- en framtidsrettet næring’. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.