Structure of mature biofilms The quantitative representation of the used species was most convincing when biofilms were grown in iHS medium. T. denticola established in high numbers and the biofilms showed the best stability during the following staining procedures. Therefore, structural analysis was focused on these biofilms. CLSM analyses of FISH stained biofilms enabled us to determine all 10 species used in the model and locate their position in the biofilms. The top layer (approximately 30 μm from the biofilm surface) and basal layer (approximately 50 μm from the disc surface) of the biofilms showed clear structural differences and a fluent transition between these layers was observed. Sunitinib chemical structure Biofilms grown in mFUM4 showed
a dominance of F. nucleatum and streptococci in the basal layer (Figure 5A). In biofilms grown in iHS, however, F. nucleatum was detectable by FISH only in the top layer as dispersed cells, while streptococci were very abundant throughout the whole biofilm (Figure 5B). Aggregations of streptococci were often mixed with V. dispar in the whole biofilm except in the top layer, where V. dispar occurred as compact microcolonies (Figure 6). In biofilms grown in mFUM4, which had a lower thickness,
this growth pattern of V. dispar was observed throughout the biofilm (Figure 5A). P. intermedia was found predominantly in the lower half of the biofilms Selleck Sorafenib forming microcolonies with diameters of about 50 μm on average (Figure 7A). T. forsythia was found mainly in the top layer of the biofilm, while none were detected in the lower half of the biofilms (Figure 7A). T. denticola grew loosely in the top layer alongside with P. gingivalis, which displayed the highest density in close proximity to T. denticola accumulations (Figure 7B). A. oris appeared as loose EPS-embedded microcolonies located in the upper half of the biofilms (Figure 8A). Campylobacter rectus was dispersed throughout the biofilm and did not form own microcolonies, but showed higher density in the top layer of the biofilm
(Figure 8B). Figure 5 Biofilms grown for 64.5 h in or mFUM4- (A) or iHS medium(B). FISH staining of a fixed biofilm; Interleukin-3 receptor the biofilm base in the side views is directed towards the top view. (A) red: F. nucleatum, white: V. dispar, green: non-hybridised cells, DNA staining (YoPro-1 + Sytox), blue: EPS. (B) cyan: streptococci, red: F. nucleatum, green: non-hybridised cells, DNA staining (YoPro-1 + Sytox). Figures show a representative area of one disc. Scale bars: 20 μm. Figure 6 Biofilms grown for 64.5 h in iHS medium. FISH staining of a fixed biofilm; the biofilm base in the side views is directed towards the top view. Cyan: V. dispar, green: non-hybridised cells, DNA staining (YoPro-1 + Sytox). Arrows: Microcolonies of V. dispar. Shown is a representative area of one disc. Scale bar: 30 μm. Figure 7 3D-reconstructions of a 146 x 146 μm section of biofilms grown for 64.5 h in iHS medium. FISH staining of a fixed biofilm. P. gingivalis and T.