Fig. 2: Effects of two protists on biofilm formation in Bacillus and within the SynCom members.

a Biofilm production of the SynCom members in the presence of Cercomonas or Naegleria, determined by the crystal violet staining method in 96-well plates (n = 7 biologically independent samples, three times the experiment was repeated with similar results); b Biofilm production of the SynCom members in the presence of Cercomonas or Naegleria measured by fresh weight biomass in 6-well plates (n = 4 biologically independent samples, 3 times the experiment was repeated with similar results); c Heatmap showing pairwise correlations between each bacterium in the SynCom or the SynCom co-cultured with the protists Cercomonas or Naegleria (n = 4 biologically independent samples); d Changes in bacterial community composition within the SynCom after co-culture with the protists Cercomonas or Naegleria (n = 4 biologically independent samples); e Biofilm formation of Bacillus and within the SynCom members co-cultured with or without the protist Naegleria sp. after 48 h of static culture in 1/2 Msgg+1/2 TSB culture medium in 6-well plates (three times the experiment was repeated with similar results); f Biofilm crystal violet staining of Bacillus and of SynCom members co-cultured with or without the protist Naegleria after 48 h of static culture in 1/2 Msgg+1/2 TSB culture medium in 96-well plates (three times the experiment was repeated with similar results); g Biofilm formation of Bacillus and of SynCom members co-cultured with or without the protist Naegleria quantified using the crystal violet staining method (OD₅₉₀) (n = 6 biologically independent samples). Different letters indicate significant differences between treatments (one-way ANOVA or Kruskal-Wallis H test with LSD for multiple comparisons, P-value < 0.05).