Global warming and microplastic pollution are increasingly recognized as critical issues associated with the use of fossil fuels and improper management of plastic end-of-life. In this context, autotrophic microalgae cultivated under sunlight emerged as a promising alternative for producing substrates that could replace petroleum-based products. Within the SEALIVE and Nenu2PHAr European projects, we focused on the cultivation of Chlorella vulgaris to provide an alternative feedstock for the production of biodegradable plastics, such as polyhydroxyalkanoates (PHAs) and thermoplastic starch (TPS). First, appropriately selected C. vulgaris strains were cultivated in 180-liter flat panel airlift reactors under natural light conditions. A key step involved inducing nitrogen deprivation in the algae, leading to an accumulation of starch granules. A carbohydrate-rich fraction, primarily composed of these starch granules, was then isolated and purified thanks to a green waterborne process. Under the Sealive project, this starch fraction was mixed with glycerol to prepare TPS. Conversely, in the Nenu2PHAr project, the starch underwent enzymatic saccharification to produce a glucose syrup. This syrup then served as a substrate for bacteria able to accumulate PHA. Additionally, the residual pigment fraction from this process was utilized as a fluorescent marker, enhancing the sorting efficiency of new bioplastic blends for recycling purpose. While biobased and biodegradable plastics like TPS and PHAs hold great potential for future markets, the complete valorization of all fractions, including those rich in proteins for use in nutraceuticals and animal feed, remains an area open for further improvement and implementation.