Seawater carbonate chemistry and growth and enzyme activities of Nitzschia closterium

• Main Authors: Li, Keqiang, Li, Min, He, Yunfeng, Gu, Xingyan, Pang, Kai, Ma, Yunpeng
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2020
• Subjects: Bottles or small containers/Aquaria <20 L; Chromista; Growth/Morphology; Laboratory experiment; Laboratory strains; Macro-nutrients; Nitzschia closterium; Not applicable; Ochrophyta; Other metabolic rates; Pelagos; Phytoplankton; Single species; Type; Species; Registration number of species; Uniform resource locator/link to reference; Treatment; Time in hours; pH; pH, standard deviation; Chlorophyll a; Chlorophyll a, standard deviation; Nitrogen, particulate; Nitrogen, particulate, standard deviation; Biomass; Biomass, standard deviation; Growth rate, maximum; Growth rate, maximum, standard deviation; Nitrogen, inorganic, dissolved; Dissolved inorganic nitrogen, standard deviation; Nitrate; Nitrite; Ammonium; Maximum nutrient uptake rate; Maximum nutrient uptake rate, standard deviation; Half saturation concentration; Half saturation concentration, standard deviation; Minimum concentration threshold; Minimum concentration threshold, standard deviation; Ratio; Ratio, standard deviation; Superoxide dismutase activity, unit per protein mass; Superoxide dismutase activity, standard deviation; Catalase activity, unit per protein mass; Catalase activity, standard deviation; Nitrate reductase activity; Nitrate reductase activity, standard deviation; Salinity; Temperature, water; Temperature, water, standard deviation; Carbon, inorganic, dissolved; Alkalinity, total; Carbonate system computation flag; Carbon dioxide; Fugacity of carbon dioxide water at sea surface temperature wet air; Partial pressure of carbon dioxide water at sea surface temperature wet air; Bicarbonate ion; Carbonate ion; Aragonite saturation state; Calcite saturation state; Calculated using seacarb after Nisumaa et al. 2010; Ocean Acidification International Coordination Centre OA-ICC; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.917678; https://doi.pangaea.de/10.1594/PANGAEA.917678

In this study, Nitzschia closterium was incubated in seawater at different pH values (8.10, 7.71, and 7.45) and using different nitrogen forms (NO3–N and NH4–N) in the laboratory. The results showed that the growth of N. closterium was inhibited by ocean acidification, with individuals under lower pH levels showing lower growth rates and lower nitrogen uptake rates for both nitrogen forms. The Vmax/Ks ratio decreased with decreasing pH, indicating the inhibition of nitrogen uptake, whereas the ratios for NH4–N cultures were higher than those for NO3–N cultures, implying the highly competitive position of NH4–N. Acidification might induce reactive oxygen species based on the result that the maximum enzyme activities of SuperOxide Dismutase (SOD) and CATalase (CAT) increased under lower pH levels. The SOD and CAT activities for the NO3–N cultures were higher than those for NH4–N cultures at the low pH level, indicating that acidification might cause more oxidative stress for NO3–N cultures than for NH4–N cultures. Thus, ocean acidification might have a more detrimental effect on the growth of N. closterium under NO3–N conditions than NH4–N conditions, with a lower ratio (γ) of the maximum growth rate to the maximum nutrient uptake rate, and a drop in nitrate reductase activity under lower pH levels. : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2019) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI). The date of carbonate chemistry calculation by seacarb is 2020-05-6.