Abstract: A method and system is provided for increasing lipids, biomass, and metabolite yields of a microalgae culture of cells and other organisms with conserved metabolic pathways compared to an untreated culture or organism when maintained under normal conditions. The method includes irradiating with electromagnetic ionizing radiation to induce rapid and reproducible hormetic metabolic activation in the organism cells. In an embodiment, the irradiation can be applied in a exponential or stationary phase of microalgae growth. The hormetic effect involves up-regulation of expression of lipid metabolism genes encoding enzymes that are involved in the biosynthesis of lipids with accumulation of energy reserves in the form of lipids and/or accumulation of other metabolites.