Carbohydrates produced in batch cultures of the surf zone diatom Asterionellopsis glacialis sensu lato: Influence in vertical migration of the microalga and in bacterial abundance

Abstract Surf zone diatoms thrive in the harsh conditions of exposed sandy beaches. The patch-forming Asterionellopsis glacialis sensu lato ( A. glacialis s. l.) is the main producer in a rich food chain in Cassino Beach, southern Brazil. This work aimed to verify the influence of sediment particles on the quantity and composition of carbohydrates produced in cultures with A. glacialis s. l. and to investigate the relationship between carbohydrate composition and bacterial abundance. The non-axenic diatom, isolated from Cassino Beach, was batch cultivated for nine days with calcined sediment (CS), fresh sediment (FR), and without sediment (Ctrl). Higher cell counts (p  − 1 ) and FR (30.3 ± 3.3 mg L − 1 ), respectively. High Performance Liquid Chromatography (HPLC) characterization of particulate carbohydrates showed increases with time in rhamnose, xylose and arabinose in all treatments. The increase of these carbohydrates has the potential to cause A. glacialis s. l. to settle or float by influencing mucus thickness and adhesiveness. A significant decrease (p