Transforming CO₂ into Nutrients: Sustainable Production of Carotenoids Using <i>Rhodotorula mucilaginosa</i> UANL-001L Cultivated on <i>Synechocystis</i> sp. PCC 6803 Biomass

In the current era of escalating atmospheric CO2 levels and its concomitant exacerbation of the greenhouse effect, the search for innovative, sustainable solutions to mitigate these impacts is urgent, particularly in addressing the global challenge of nutrient production. This study explores the potential of using captured carbon dioxide as a dual resource for mitigating climate change and developing nutrients and food. Specifically, we investigate the use of Rhodotorula mucilaginosa UANL-001L to convert CO2 captured from a CO2-enriched atmosphere into carotenoids. This process involves cultivating R. mucilaginosa UANL-001L on Synechocystis sp. PCC 6803 biomass, itself produced from an enriched CO2 source. Our findings reveal that a 30-day cultivation period under these conditions leads to the production of 1 g/L of reducing sugars from the Synechocystis sp. PCC 6803 biomass. The efficiency of sugar production correlates directly with the duration of CO2 exposure, enabling the production of up to 3.6 μg of carotenoids. This results in a substantial yield of 220 mg/g of yeast biomass, representing a 50% increase in production compared to traditional methods using yeast malt. Our research introduces a groundbreaking approach that combines CO2 capture and biological conversion, highlighting a sustainable pathway for nutrient and food production from CO2. The versatility of this method and its potential applicability across various industrial sectors, including food processing, supplements, and bioenergy, underscores its compatibility with sustainable industrial processes. This approach not only offers a solution to the challenge of atmospheric CO2 reduction but also opens new avenues for addressing global food security challenges, signaling a significant shift in production paradigms toward sustainability.