With the decline of fossil fuels and rising climate concerns, renewable energy sources have gained importance. Microalgae, a diverse group of organisms, offer promising applications in biotechnology and biofuel production due to their ability to convert atmospheric CO₂ and their rich biochemical composition. Despite their potential as biofuel sources, challenges remain in dewatering, growth rate optimization, and product synthesis. This study evaluates five microalgae species isolated from Baja California, Mexico, assessing their growth rate, biomass production, proximate composition, and fatty acid content to determine their suitability for biofuel production.
The growth rate (p<0.05), total dry weight (p<0.05), organic dry weight (p<0.05), ash content (p<0.05), and biomass productivity (p<0.05) differed among eleven microalgae strains. The proximate composition differed (p<0.05) between the eleven microalgae strains. The lipids contents were higher in Cymbella sp. (strain 2) (42.46±1.06%) (p<0.05). The carbohydrate content was higher (p<0.05) in Aphanocapsa marina (42.40±1.18%). The protein content was significantly higher (p<0.05) in Chlamydomonas mexicana (52.83±0.60%). The contents of saturated (SFAs) (p<0.05), monounsaturated (MUFAs), and polyunsaturated (PUFAs) (p<0.05) fatty acids among the eleven microalgae strains were different. The most important indicators of biodiesel properties are the cetane number (CN), iodine value (IV), and saponification value (SV). It was concluded that Chlorella vulgaris was an adequate strain to be used in the production of biodiesel due to their high amount of palmitic acid, oleic acid, and alpha-linolenic acid, by high values of IV (147.27 g I2 /100 g), and SV (210.96 mg KOH/g) and the highest value of CN (48.88). The diatom Cymbella sp. is a promising strain for biodiesel production due to its high values of lipid content (42.46%), lipid productivity (1.24 g/L/day), growth rate (0.67 divisions/day), and IV (197.93 g I2 /100 g), and by the lowest values of generation time (35.60 h) and SV (208.85 mg KOH/g). Another promising strain for biodiesel production is Porphyridium cruentum due its high values of biomass productivity (0.038 g/L/day), lipid productivity (0.80 g/L/day), CN (45.60) and IV (220.15 g I2 /100 g), and by the low generation time and SV (199.25 mg KOH/g).