Student Research

Community Dynamics, Biochemical Composition and Safety of Microalgae grown in Dairy Manure Wastewaters

California Dairy Farms produce more than 30 million tons of manure waste annually. Improper disposal, and run off impact surface and groundwater, which affect wild life and public drinking wells. Nutrient recovery from organic wastewaters using microalgae can be coupled with the bioconversion of sunlight into biofuels. Furthermore, the high protein content in algal cells, as well as high amounts of unsaturated lipids, make microalgae desirable for feed supplement production. The lab aims to elucidate species-specific carbon allocation, proximate composition, nutritional value and safety of axenic strains to promote the management of outdoor ponds and maximize productivity. DNA from highly conserved 18S rDNA regions selective to Chlorophyceae (CHLORO F/R; Moro et al.) was amplified. PCR products were sequenced to construct a phylogenic tree for species identification. Primary effluent was surveyed for potential aquatic pathogens using: Next Generation Sequencing (NGS), GC-MS, and ELISA. One and two-dimensional NMR techniques were used to quantify the soluble metabolites, essential amino acids, and carbohydrates. Nucleic acids were also quantified using a fluorescent dye, propidium iodide. Total lipid content and composition were determined through in situ transesterifications of fatty acid methyl esters (FAMEs). Heavy metal concentrations were determined using inductively coupled plasma mass spectroscopy (ICP-MS). Our findings suggest that algal biomass would be a promising safe feed supplement due to the high amino acid, protein composition, unsaturated lipids and low abundance of nucleic acid.