Fig. 4: mMVs mediate interspecies heme delivery.
A. mMVs mediated interspecific heme delivery is a function of fusion efficiency and homology distance. The heme-incubated mMVs and heme-free (unincubated) mMVs were added to multiple species as the sole iron source, and the maximal OD600 was recorded. The homology distance was calculated by MEGA6. The fusion efficiency was measured by FM4-64-based membrane labeling as described in the “Materials and methods”. The membrane fusion efficiency of heme-incubated mMVs to DQ12-45-1b was considered as 100%. To calibrate the growth of different strains, the maximal growth at the optimal conditions of each bacterium was used as 100%. 45-1b, D. sp. DQ12-45-1b, Dn D. natronolimnaea, Dp D. psychralcaliphila, Dm D. maris, Dc D. cinnamea, Re R. erythropolis, Ms M. smegmatis, Cg C. glutamicum, Bs B. subtilis, Bc B. cereus, Pf P. fluorescens, Ec E. coli, Ab A. baumannii. Error bar represents three independent replicates. B. Fitting analysis of homology distance, heme delivery, and fusion efficiency.
