Figure 2. Mixed-species biofilms provide a niche for growth of anaerobic bacteria.
(A–D) CFU/ml of indicated species grown in biofilms in monoculture or co-culture under oxic or anoxic conditions. Cells were collected from biofilms only (not from the media above the biofilm) at 1.5, 4, 24, 48, and 72 h, and plated for CFUs. A) C. albicans and/or C. perfringens in oxic conditions. B) C. albicans and/or B. fragilis in oxic conditions. C) C. albicans and/or C. perfringens in anoxic conditions. D) C. albicans and/or B. fragilis in anoxic conditions. E) Oxygen was measured in biofilms composed of the indicated species using a STOX-Sensor. Readings were taken every 10 μm from the top to the bottom of the biofilm. For all graphs, the mean of at least two replicates is shown, with error bars representing standard deviation. See also Figure S2.