FIGURE 8.

Relative abundance of genes related to quorum sensing, bacterial motility, flagellar assembly, chemotaxis, biofilm-formation for P. aeruginosa, V. cholerae and E. coli, bacterial toxins, and invasion of epithelial cells as assigned by KEGG database. The bars depict the mean and standard deviation of the replicate compost piles without (E1/E2) and with biochar (E1-B/E2-B) for start and end of composting. 145 genes were assigned to quorum sensing, 132 to bacterial motility, 39 to flagellar assembly, 26 to chemotaxis, 87 to biofilm-formation in P. aeruginosa, 78 to biofilm-formation in V. cholerae, 47 to biofilm-formation in E. coli, 40 to bacterial toxins and 65 to invasion of epithelial cells. Asterisks indicate the p-values obtained from Student’s t-test (*p < 0.05) representing the statistical significance of the data. Non-significant values are indicated by “n.s.” P-values were calculated to compare start with end samples of composting for all four compost piles combined (no differentiation of the treatments).