Eastern Kentucky University
Characterization of Gene Expression During Lipid Induction in the Microalga Chlorella Protothecoides
Institution
Eastern Kentucky University
Faculty Advisor/ Mentor
Rebekah L. Waikel
Abstract
Microalgae are a promising source for sustainable biofuel production, but large-scale production is cost-prohibitive. In order to implement biotechnology and make production more costeffective, we must first understand the genome and metabolic pathways of relevant microalgae. Our purpose was to advance the understanding of how gene expression influences lipid production in Chlorella protothecoides. This information can be used to develop biotechnology to improve algal biofuel production. Our primary objectives were: 1.) to identify 10 gene expression markers for lipid production and define their patterns of temporal expression, and 2.) to use these markers to determine how lipid production is affected by changes in: pH, light, and micronutrients. We determined that algae grown in nitrogen deficient conditions have a 33% higher lipid content than algae grown in nitrogen sufficient conditions. By comparing genetic information from algae grown in nitrogen sufficient (low lipid production) and nitrogen deficient (high lipid production) conditions, we identified 10 candidate genes for involvement in lipid production. We used cDNA from algae grown in low and high lipid producing conditions to quantitate the expression patterns of our candidate genes and established a “lipid production profile” from this data. We then altered pH, light, and micronutrients and compared gene expression patterns under these conditions to those in our established profile to predict whether the algae was in a state of high lipid production. In order to test our hypotheses, we directly measured the amount of lipids using fluorescent dyes. Once experiments are finished and data is compiled, we will have a more complete understanding of the genetic mechanisms underlying lipid production in Chlorella protothecoides. Researchers can use this information to develop biotechnology to improve algal biofuel production and make it a cost-effective alternative to traditional fossil fuels.
Characterization of Gene Expression During Lipid Induction in the Microalga Chlorella Protothecoides
Microalgae are a promising source for sustainable biofuel production, but large-scale production is cost-prohibitive. In order to implement biotechnology and make production more costeffective, we must first understand the genome and metabolic pathways of relevant microalgae. Our purpose was to advance the understanding of how gene expression influences lipid production in Chlorella protothecoides. This information can be used to develop biotechnology to improve algal biofuel production. Our primary objectives were: 1.) to identify 10 gene expression markers for lipid production and define their patterns of temporal expression, and 2.) to use these markers to determine how lipid production is affected by changes in: pH, light, and micronutrients. We determined that algae grown in nitrogen deficient conditions have a 33% higher lipid content than algae grown in nitrogen sufficient conditions. By comparing genetic information from algae grown in nitrogen sufficient (low lipid production) and nitrogen deficient (high lipid production) conditions, we identified 10 candidate genes for involvement in lipid production. We used cDNA from algae grown in low and high lipid producing conditions to quantitate the expression patterns of our candidate genes and established a “lipid production profile” from this data. We then altered pH, light, and micronutrients and compared gene expression patterns under these conditions to those in our established profile to predict whether the algae was in a state of high lipid production. In order to test our hypotheses, we directly measured the amount of lipids using fluorescent dyes. Once experiments are finished and data is compiled, we will have a more complete understanding of the genetic mechanisms underlying lipid production in Chlorella protothecoides. Researchers can use this information to develop biotechnology to improve algal biofuel production and make it a cost-effective alternative to traditional fossil fuels.