Dataset: Grazing experiment 4: cell carbohydrates

The phytoplankton Rhodomonas sp. CCMP 755 was grown semi-continuously in atmosphere controlled chambers at three different CO2 treatment concentrations; Ambient (400ppmv), Moderate (750ppmv), and High (1000ppmv).  Cultures were diluted daily starting day 4 with pre-equilibrated media containing f/50 nutrients.  Some of the culture removed was used to evaluate chemical parameters.  Samples for carbohydrate mass were taken by gravity filtering 30 ml of culture through muffled GF/F filters. Filters were wrapped in aluminum foil and stored at -80°C until analysis.  Prior to analysis, filters were extracted in 1 ml of 95% H2SO4 and 1 ml of nanopure water in a sonication bath for 30 minutes and then 20 hours at room temperature.  After extraction samples were centrifuged at 10,000 rpm for 6 minutes.  1.6 mls of the extract was combined with 4 mls of concentrated H2SO4 and 0.8 mls of 10% phenol and allowed to react for 30 minutes.  Samples were analyzed colormetrically using a Spec20D+ spectrophotometer at 485 nm and compared with standards made from fructose.