Microalgae have gained popularity over the century due to their numerous intrinsic properties superior to higher plants, making them a potential target and feedstock for the development of biotechnological products in various fields. The storage of carbohydrates within microalgae cells positions them as a promising reservoir for biofuel production and a range of other valuable bioproducts, encompassing biological compounds, nutritional supplements, and more. Key determinants influencing microalgae carbohydrate levels comprise nutrient availability, light intensity, temperature, and CO2 concentrations. In this context, the CO2 concentration plays a key role, as it is one of the main factors influencing the photosynthetic processes. This study aimed to explore the impact of different CO2 concentrations on the carbohydrate profile of biomass sourced from Chlorella vulgaris sp. BB-2 and Scenedesmus quadicauda B-1. The findings revealed that a CO2 concentration of 2% v/v notably enhanced carbohydrate accumulation, reaching 75.5% for Chlorella vulgaris sp. BB-2 and 72.0% for Scenedesmus quadicauda B-1.