Bioprospecting Native Oleaginous Microalgae for Wastewater Nutrient Remediation and Lipid Production

Abstract

Subtropical climate in Florida offers a unique opportunity for sustainable biofuel production using native microalgae cultivated in untreated wastewater. This study bioprospected oleaginous microalgal consortia from a wastewater holding tank at the Thomas P. Smith Water Reclamation Facility in Tallahassee, Florida, aiming to identify strains capable of both nutrient remediation and lipid accumulation. Using Fluorescence Activated Cell Sorting (FACS), chlorophyll-containing cells were isolated and cultured on BG-11 media. Shotgun metagenomics revealed that the most robust consortia- labeled C3, C4, and C9, were dominated by Chlamydomonas, Acutodesmus, and Volvox spp., alongside diverse bacterial, fungal, and archaeal communities. Functional gene analysis indicated active pathways for photosynthesis, lipid biosynthesis, and nutrient assimilation. In microcosm experiments, these consortia achieved up to 100% ammonia, 95% phosphorus, and 89% nitrate removal, outperforming control treatments. Lipid screening confirmed significant accumulation, with consortium C9 showing the highest yield. These findings underscore the potential of native microalgal consortia for integrated wastewater treatment and biofuel production, advancing circular bioeconomy strategies for subtropical regions.