SusChEM:Characterization of oxidative stress response to improve microalgae-based biofuel production in wastewater

University Of California-Davis, Davis CA

Investigators

Abstract

PI: Annaliese Franz Proposal Number: 1512250 Microalgae are single-celled photosynthetic organisms that grow on atmospheric carbon dioxide, sunlight, and dissolved mineral nutrients. Under the proper conditions, microalgae also produce fatty acids stored as lipids, which can be readily converted to biofuel such as biodiesel. To reduce the costs of algal biofuel production processes and at the same time improve sustainable reuse of water, algae can be grown on dissolved mineral nutrients in various types of waste water. However, the use of waste water as nutrient source may put stress on the growth and metabolism of the organism. This project will study the possible link between oxidative stress and lipid production in industrially-relevant strains of microalgae using techniques of molecular biology. The outcomes of the research may suggest ways to minimally treat waste water to make it more amenable for use in algal biofuel production. The educational aspects of this project focus on mentoring middle school girls to stimulate their interest in science and engineering using bioenergy modules developed for this purpose. The overall goal of this research is to characterize oxidative stress response and regulation of gene expression in industrially-relevant microalgae strains in order to identify improved conditions for coupling biofuel production with wastewater remediation. The overall approach is to correlate relevant phenotypes with metabolomic and transcriptomic studies for lipid producing strains of microalgae to understand global metabolism and lipid pathway changes under conditions that promote oxidative stress response, including kinetic and concentration effects of treated cultures with a primary focus on algae cultivation in wastewater. High lipid producing strains (P. tricornutum, C. sorokiniana and N. salina) will be selected for study based on their industrial and scientific relevance as well as availability of genomic information. The research plan has three objectives. The first objective is to characterize oxidative stress response and regulation of gene expression in lipid producing microalgae, including kinetic and concentration effects for two scenarios - peroxide-induced lipid accumulation and cultivation on dairy wastewater. The second objective is to evaluate application of antioxidants to improve oxidative stress tolerance in high-oil-producing microalgae. Finally, the third objective is to evaluate effect of peroxide- and antioxidant treatment as variables to improve biomass and lipid production of microalgae cultured in wastewater. The education and outreach activities of this project focus on bioenergy topics, and are designed to broaden participation of women and under-represented students in STEM through existing programs at the University of California at Davis, particularly for middle school girls. A bioenergy module focusing on renewable energy and environmental sustainability will be developed to help deliver these education and outreach programs.