Bacterial stimulation of lipid vesicle production in green microalga Dunaliella tertiolecta

  • Author / Creator
    Catherine C Bannon
  • Algae and bacteria form complex interactions through the exchange of bioactive molecules and nutrients. A wide range of phenotypes, and often their very survival, are influenced by these chemically mediated relationships, shaping the ecology and diversity of marine communities. Here we sought to uncover the effect of various marine bacteria on lipid production and storage in the biofuel candidate, unicellular green alga Dunaliella tertiolecta (CCMP1320). The roseobacter Phaeobacter italicus R11 was found to increase D. tertiolecta’s lipid per biomass ~25%, with no effect on growth rate or photosynthetic health, during 16 d co- cultivation experiments. Although the amount of lipid produced increased, the fatty acid methyl esters composition was not altered by P. italicus. Imaging flow cytometry and fluorescence microscopy revealed that the increase in lipid per biomass coincided with the production of algal-derived, extracellular lipid vesicles. The lipid vesicles were not degraded but accumulated in abundance and could fuse, forming larger vesicles. This is the first description of bacterial- stimulated lipid vesicle production in green microalgae, and these findings could expedite algal lipid harvesting during biofuel production.

  • Subjects / Keywords
  • Graduation date
    Fall 2019
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
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