Growth of Chaetoceros affinis and bacteria in response to initial density manipulations

Daily measurements of bacteria and Chaetoceros affinis (diatom; RCC6348; roscoff-culture-collection.org) cell densities and C. affinis cell height and diameter in a short-term (4 days) experiment where initial densities of phytoplankton and bacteria were manipulated. Phytoplankton and bacteria were separated using a 20 µm mesh and reassembled in different proportions. Treatment levels were High phytoplankton, Low phytoplankton, High bacteria, Low bacteria, and Intermediate phytoplankton and bacteria densities. Experimental bottles contained 200 ml sterile filtered artificial seawater with 19.7 µmol/L nitrate, 18.1 µmol/L silicate, 1.2 µmol/L phosphate and vitamins, selenium, and trace metals according to f/8 media before inoculation with 50 ml phytoplankton-bacteria mix.