Fig. 6

Antibiotic treatments in exploratory experiments on M. pusilla and M. commoda. Treatments with 10 mM fosfomycin and penicillin show changes between the penicillin treatment and control at each time point but, apart from the 8 h time point (* indicates p < 0.005), these differences are not significant (p > 0.05). Antibiotics were added 1 h after lights on (0 h timepoint) to cultures acclimated to a 14 h light/10 h dark cycle. Thus, 14 h was 1 h after lights off and the 18 h timepoint was 5 h into the dark period. a Growth rate of CCMP1545 and RCC299 in controls and treatments. Chlorophyll-derived red fluorescence in b CCMP1545 and (c) RCC299 normalized to bead standards. Forward angle light scatter (FALS), an indicator of cell size in (d) CCMP1545 and (e) RCC299 normalized to bead standards. Error bars reflect the standard deviation of biological duplicates