Unveiling the Cultivation of Nostoc sp. under Controlled Laboratory Conditions.

Simple Summary: The study focused on cultivating the cyanobacterial strain Nostoc sp. 136 under controlled laboratory conditions. Various factors such as nutrient media, initial biomass concentration, nutrient supplementation, and light conditions were investigated to optimize growth and productivity. Results showed that the strain adapted well to the laboratory conditions, with the highest growth rates observed at lower initial biomass concentrations and with mBG11 medium. Nutrient supplementation, particularly nitrogen, showed potential for enhancing growth, while different light wavelengths had varied effects on growth and productivity. Biochemical analysis revealed promising levels of proteins and phycobiliproteins, with potential applications in biotechnology. The study highlighted the suitability of Nostoc sp. 136 for laboratory cultivation and suggested avenues for further research, particularly in exploring biomass composition and bioactivities. Cyanobacteria, photoautotrophic Gram-negative bacteria, play a crucial role in aquatic and terrestrial environments, contributing significantly to fundamental ecological processes and displaying potential for various biotechnological applications. It is, therefore, critical to identify viable strains for aquaculture and establish accurate culture parameters to ensure an extensive biomass supply for biotechnology purposes. This study aims to establish optimal laboratory batch culture conditions for Nostoc 136, sourced from Alga2O, Coimbra, Portugal. Preliminary investigations were conducted to identify the optimal culture parameters and to perform biomass analysis, including protein and pigment content. The highest growth was achieved with an initial inoculum concentration of 1 g.L−1, using modified BG11 supplemented with nitrogen, resulting in a Specific Growth Rate (SGR) of 0.232 ± 0.017 μ.day−1. When exposed to white, red, and blue LED light, the most favourable growth occurred under a combination of white and red LED light exhibiting an SGR of 0.142 ± 0.020 μ.day−1. The protein content was determined to be 10.80 ± 2.09%. Regarding the pigments, phycocyanin reached a concentration of 200.29 ± 30.07 µg.mL−1, phycoerythrin 148.29 ± 26.74 µg.mL−1, and allophycocyanin 10.69 ± 6.07 µg.mL−1. This study underscores the influence of light and nutrient supplementation on the growth of the Nostoc biomass. [ABSTRACT FROM AUTHOR]