Dataset: Diatom Matrix Mass Spectrometry

An axenic Thalassiosira pseudonana 1335 culture (National Center for Marine Algae) was grown in 500 ml of L1 +Si medium[1] in a 600 ml vented tissue culture flask at 18 °C under 16 h light at 160 µmol photons/m^2/s and 8 h dark. After the diatom cultures had been growing for 7 d, bacteria pre-grown in 1/2 YTSS medium at 30 °C (Ruegeria pomeroyi DSS-3 (treatment A) and Stenotrophomonas sp. SKA14 (treatment D)) or 1/10 YTSS medium at 25 °C (Polaribacter dokdonensis (treatment E)) were washed 5 times in sterile L1 medium and inoculated into the diatom cultures and glucose controls at ~10^6 (Stenotrophomonas sp. and P. dokdonensis) or ~10^7 (R. pomeroyi) cells/ml. 3 or 4 replicates were collected for each co-culture. Axenic T. pseudonana and unamended L1+Si medium were maintained and sampled alongside the co-cultures as controls (treatment X and C). Samples were collected after 48 h.

Microbial cells were removed from co-cultures by filtration through 0.2 µm pore-size filters at 8 h, 24 h, and 49 h after bacterial inoculation. Uninoculated medium served as the blank. Metabolites were derivatized with benzoyl chloride (Widner et al. in prep), extracted using a solid phase resin (Agilent, Bond Elut PPL), and analyzed using ultra high performance liquid chromatography coupled with electrospray ionization and tandem mass spectrometry (UHPLC-ESI-MSMS).

Data were processed using Skyline (Pino et al. 2017, Henderson et al. 2018) and MATLAB.