Effects of Climate Change on the Production of Polysaccharides and Phycobiliproteins by Nostoc commune Vaucher ex Bornet et Flahault

Abstract

Nostoc commune synthesizes polysaccharides and phycobiliproteins under natural conditions, but little is known about how environmental changes could affect their production. In this study, colonies of N. commune were subjected to increases in ultraviolet radiation, ammonium concentration, electrical conductivity, and temperature, to assess the potential changes in the concentrations of polysaccharides and phycobiliproteins. The results indicate that UVB radiation significantly increased the synthesis of polysaccharides (F = 62.691; p < 0.01), while UVA radiation caused a significant increase in the production of total phycobiliproteins (F = 22.472, p < 0.01) phycocyanin (F = 8.546, p < 0.01), phycoerythrin (F = 12.876, p < 0.01), and allophycocyanin (F = 58.143, p < 0.001). Also, 50 μM NH4Cl significantly increased the synthesis of polysaccharides (F = 45.706; p < 0.01) while increased near significant total phycobiliproteins (F = 5.043, p < 0.1), phycoerythrins (F = 4.57, p < 0.1), allophycocyanin (F = 4.892, p < 0.1), and phycocyanin (F = 4.921, p < 0.1). Furthermore, a conductivity value of 4 mScm− 1 enhanced near significant the production of polysaccharides (F = 4.816; p < 0.1) and phycocyanin (F = 9.728, p < 0.1). Nevertheless, a significant effect of total phycobiliproteins was observed (F = 23.686, p < 0.01), as well as allophycocyanin (F = 57.092, p < 0.001), and phycoerythrin (F = 13.928, p < 0.01). Finally, the optimal temperature for the synthesis of polysaccharides was 30 °C. Also, 30 ºC significantly increased the synthesis of total phycobiliproteins (F = 292.211, p < 0.001), as well as on phycocyanin (F = 126.433, p < 0.001) and allophycocyanin (F = 7.991, p < 0.05). These data indicate the ability of N. commune to modify its synthesis of polysaccharides and phycobiliproteins in response to extreme environmental conditions related to climate change, underscoring the interest in N. commune for future applied research on the biotechnological and pharmaceutical production of both types of compounds.