Fig. 5.

E. coli releases porphyrins that stimulate Bt growth. The Heme-PPIX-Screen setup was used to determine whether E. coli stimulates Bt growth. E. coli WT, ∆hemA (heme biosynthesis pathway inactivated), and pHemA (E. coli MG1655 containing the pHemA plasmid that induces porphyrin overexpression [25]) were grown overnight. Supernatants of overnight cultures were heated to 90 °C for 10 min and then filter-sterilized, and deposited in the wells