Screening of green microalgae for starch accumulation under nutrient depletion

Microalgae are considered an interesting feedstock for biorefinery nowadays. Microalgae are photosynthetic microorganisms and need macro and micronutrients for their growth. The lack of these nutrients leads to modification of the metabolic pathways and, consequently, to changes in biomass composition (Ran et al.,2019). One of the storage metabolites that can be accumulated in starved conditions is starch, mainly in green microalgae. Starch represents an interesting compound given its multiple applications, e.g., for bioplastic and bioethanol production, as functional food ingredient, chemical additive, and bulking agent (da Maia et al., 2020; Gifuni et al., 2017). The present study aims to identify microalgae strains able to accumulate high amounts of starch with a screening carried out under nitrogen and phosphorus depletion. The most interesting strains will be selected and tested in further studies under different cultivation conditions in order to maximize starch accumulation. Starch will be finally tested for industrial application in the nutraceutical sector.