Methods of inducing or increasing lipid and protein production in microalgae are disclosed. Methods of enhancing microalgae biomass are also disclosed. The methods may comprise inoculating a culture media with microalgae and propagating the microalgae under heterotrophic growth conditions. The heterotrophic growth conditions may comprise inhibiting exposure of the inoculated culture media to light. The methods may further comprise delivering oxygen into the inoculated culture media. Additionally, lipids, proteins, and other cellular components may be isolated and purified from microalgae cultivated under the disclosed methods.