Exploring the biodiesel production potential of marine microalgae Nodosilinea nodulosa SNMVBTAR001 from Kerala coastal region, India

Microalgae-derived biodiesel has emerged as a promising solution to meet the increasing global demand for carbon-free and environmentally sustainable energy. This study explores the diversity of microalgae across seasons in Kerala, India, to assess their potential for biodiesel production. A total of Ninety marine microalgal isolates were analyzed, revealing Cyanophyceae sp. as the dominant group (67.64%), followed by Bacillariophyceae (22.54%), Chlorophyceae (5.88%), Xanthophyceae (1.96%), and Trebouxiophyceae (1.96%). Microalgae species distribution varied across regions, with Munnakal region exhibiting the highest diversity. Seasonal fluctuations played a significant role, with diversity peaking during pre-monsoon, followed by post-monsoon, summer, and winter. Five isolates with the highest growth (OD values) were identified, and SNMVBTAR007 (285 +/- 1.5 mg/L) and SNMVBTAR001 (294 +/- 2.0 mg/L) displayed the highest biomass concentration. Lipid analysis revealed SNMVBTAR001 (59%) and SNMVBTAR044 (55%) as having the highest lipid concentrations. Molecular characterization confirmed their identification as Nodosilinea nodulosa. Transesterification of extracted microalgal lipids yielded biodiesel meeting ASTM and EN standards. Fatty acid analysis indicated the presence of desirable fatty acids, particularly oleic acid. Qualitative assessments, including density, acid value, flashpoint, and soap content, aligned with biodiesel standards. Nodosilinea nodulosa SNMVBTAR001, a potential candidate for biodiesel production, with maximum efficiency of 23.10 km/L in an electrical generator. This study underscores the promise of Nodosilinea nodulosa microalgae for sustainable biodiesel production, offering eco-friendly energy solutions and reduced carbon emissions. Further research is needed to optimize cultivation and production techniques for largescale biodiesel production, contributing to a greener and more sustainable energy future.