Seawater carbonate chemistry and microbial polysaccharide degradation during experiments with phytoplankton Emiliania huxleyi (strain PML B92/11) and natural bacteria community, 2010

• Main Authors: Piontek, Judith, Lunau, Mirko, Händel, Nicole, Borchard, Corinna, Wurst, Mascha, Engel, Anja
• Format: Dataset
• Language: English
• Published: PANGAEA 2010
• Subjects: alpha-glucosidase activity per cell; Bacteria; abundance; standard deviation; beta-glucosidase activity per cell; Carbon; organic; particulate; Cell-specific glucosidase activity; Combined glucose loss; Element analyser CNS; EURO EA; EPOCA; European Project on Ocean Acidification; Experimental treatment; FACSCalibur flow-cytometer (Becton Dickinson); High Performance anion-exchange chromatography; Light:Dark cycle; Measured; Particulate organic carbon loss; pH; Polysacchrides loss; Radiation; photosynthetically active; Sample ID; see reference(s); Temperature; water; Time; incubation; WTW 340i pH-analyzer and WTW SenTix 81-electrode; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.775815; https://doi.org/10.1594/PANGAEA.775815

With the accumulation of anthropogenic carbon dioxide (CO2), a proceeding decline in seawater pH has been induced that is referred to as ocean acidification. The ocean's capacity for CO2 storage is strongly affected by biological processes, whose feedback potential is difficult to evaluate. The main source of CO2 in the ocean is the decomposition and subsequent respiration of organic molecules by heterotrophic bacteria. However, very little is known about potential effects of ocean acidification on bacterial degradation activity. This study reveals that the degradation of polysaccharides, a major component of marine organic matter, by bacterial extracellular enzymes was significantly accelerated during experimental simulation of ocean acidification. Results were obtained from pH perturbation experiments, where rates of extracellular alpha- and beta-glucosidase were measured and the loss of neutral and acidic sugars from phytoplankton-derived polysaccharides was determined. Our study suggests that a faster bacterial turnover of polysaccharides at lowered ocean pH has the potential to reduce carbon export and to enhance the respiratory CO2 production in the future ocean.