Figure 4

Fluorescent microscopy confirmed cell ratios. Fluorescent microscopy using labeled antibodies confirmed the presence of each species in the community. Samples were stained with DAPI and fluorescently labeled antibodies: green for D. vulgaris and red for C. cellulolyticum. G. sulfurreducens cells were stained blue by DAPI as described in the Materials and Methods section. (A) An artificial mixture of 1:1:1, C. cellulolyticum: D. vulgaris:G. sulfurreducens. Each image was of the same microscopic field. Two separate images taken at different fluorescent wavelengths were merged to form the image on the left showing C. cellulolyticum and D. vulgaris. The image in the center was taken with DAPI and all cells are visible. The image on the right resulted from merging the fluorescent and DAPI images and reveals the G. sulfurreducens cells as stained blue by DAPI. (B) The three species community culture shown in Figure 2 and described in the text was sampled during steady state growth and stained with DAPI and fluorescently labeled antibodies and merged as described above for (A). For (A) and (B) Arrows indicate the same cells of C. cellulolyticum, C.c., D. vulgaris, DvH, and G. sulfurreducens, G.s., imaged under the different conditions.