Enhancing methane yield from microalgae: abiotic stress and cells disruption with quartz powder

This study investigates the biochemical methane potential (BMP) of microalgal biomass, introducing a novel cells disruption method using quartz powder (SiO₂). A two-phase algae cultivation, involving nitrogen deprivation and salinity shifts, was employed to biochemically modify the biomass of two brackish green algae strains, Chlorella vulgaris and Monoraphidium contortum, enhancing their methane (CH₄) production potential. Mechanical disruption of the algal cells further increased BMP, with C. vulgaris yielding 305 mL CH₄/g volatile solids (VS) and M. contortum reaching 324 mL CH₄/g VS, reflecting respective increases of 51 % and 86 %. The integration of this efficient mechanical cell disruption method with a simple, stress-based cultivation strategy presents significant potential for enhancing the methane yield of microalgal biomass.