Nitrogen sources and iron availability affect pigment biosynthesis and nutrient consumption in anabaena sp. Utex 2576

Abstract

Anabaena sp. UTEX 2576 metabolizes multiple nitrogen (N) sources and is deemed a bio-technological platform for chemical production. Cyanobacteria have been identified as prolific pro-ducers of biofertilizers, biopolymers, biofuels, and other bioactive compounds. Here, we analyze the effect of different N‐sources and Fe availability on the bioproduction of phycobiliproteins and β‐carotene. We characterize nutrient demand in modified BG11 media, including data on CO2 fixation rates, N‐source consumption, and mineral utilization (e.g., phosphorus (P), and 11 metallic el-ements). Results suggest that non‐diazotrophic cultures grow up to 60% faster than diazotrophic cells, resulting in 20% higher CO2‐fixation rates. While the production of β‐carotene was maximum in medium with NaNO3, Fe starvation increased the cellular abundance of C‐phycocyanin and allo-phycocyanin by at least 22%. Compared to cells metabolizing NaNO3 and N2, cultures adapted to urea media increased their P, calcium and manganese demands by at least 72%, 97% and 76%, re-spectively. Variations on pigmentation and nutrient uptake were attributed to changes in phycocy-anobilin biosynthesis, light‐induced oxidation of carotenoids, and urea‐promoted peroxidation. This work presents insights into developing optimal Anabaena culture for efficient operations of bioproduction and wastewater bioremediation with cyanobacteria.