Method and evaluation thereof of yeast extract separation on the growth of microalgae

• Author / Creator

  Volk, Andrew James Alexander

• Microalgae grow heterotrophically and produce high value pigments, nutraceuticals, pharmaceuticals, feeds, and biofuels. The growth rate, nutrient medium, growth density, and oil content strongly affect the economics of heterotrophic microalgae fermentation systems. This thesis explores the growth promoting properties of yeast extract, a complex media component, on the growth of Auxenochlorella protothecoides by solvent separation of yeast extract. Complete yeast extract was found to increase the growth rate of A. protothecoides, but the effect saturates above initial media concentrations of 4 g/L. Yeast extract partitions in several solvents. In methanol, the yeast extract partially dissolves. The solid portion boosts the initial growth rate of A. protothecoides above that of complete yeast extract by 149.4% in cell count and 24.7% in dry weight. The isopropanol/water separation is a liquid/liquid separation and produces a denser extract fraction (IT) that promotes the initial cell count of A. protothecoides by 55.6% above the maximal effect of yeast extract.

• Subjects / Keywords

  • Microalgae
  • Yeast extract
  • Separations
  • Solvent extractions

• Graduation date

  Fall 2014

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3N29PH8Q

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.