Effects of environmental factors and nutrient availability on the biochemical composition of algae for biofuel production
Francis-Dominic Makong Ekpan, Merit Oluchi Ori, Humphrey Sam Samuel
Abstract
The biochemical composition of algae is determined by environmental variables and nutrient availability, which have a significant impact on its viability as a sustainable biofuel source. This article discusses the effects of important factors on algal growth and lipid accumulation, which are essential for the production of biofuel, including temperature, salinity, light intensity, and carbon dioxide concentration. The Novelty of the study provides a detailed biochemical analysis of multiple microalgal strains with an evaluation of how environmental factors and nutrient availability. We profiled twelve strains ranging from Arthrospira platensis (F&M-C256) to Nannochloropsis oceanica (F&M-M24) for protein, carbohydrate, lipid, total dietary fiber (TDF), ash, and moisture (all % dry weight ± SD, n = 3). A. platensis exhibited the highest protein content (63.9 ± 1.0%), whereas Tetraselmis suecica F&M-M33 (stationary-phase) reached 36.8 ± 1.5% carbohydrates. Lipid content peaked in Chlorella sorokiniana IAMC-212 (27.9 ± 1.3%) and T. suecica F&M-M33 (nutrient-replete; 28.5 ± 1.2%), with N. oceanica also high at 28.2 ± 2.0%. Strains differed markedly in TDF (below detection to 17.0%) and ash (4.0–22.0%), underscoring species-specific trade-offs between macromolecules. Our findings establish a quantitative baseline enabling downstream studies on how environmental parameters (temperature, light, salinity, CO₂) and nutrient regimes (N, P) can be tuned to shift metabolic allocation toward desired biofuel precursors. To scale up the production of microalgal biofuel in a way that is both economical and environmentally sustainable, it is imperative to comprehend these linkages. Algal biofuel yields improve by optimizing light, nutrients, and stress to boost lipid production and sustainability. Light and temperature changes microalgae metabolism such as boosting lipids, altering proteins, and driving biofuel yield. Phosphorus deprivation similarly redirects metabolism toward carbohydrate accumulation in cyanobacteria like Anabaena variabilis and Nostoc muscorum.