Figure 4. Molecular characterization of PHA and PHB polymers obtained from 24 h co-cultures with B. bacteriovorus strains.

(a) Polydispersity index (PDI) values of the PHA obtained from the co-cultures of B. bacteriovorus HD100 and Bd3709 strains preying on PHA-accumulating P. putida KT2440 or KT42Z. (b) PDI values of the PHB obtained from B. bacteriovorus HD100 and Bd2637 strains preying on PHB-accumulating E. coli ML35 (pAV1). Polymer granules were directly isolated from the co-cultures sediments with chloroform (PHA) or dichloromethane (PHB). As an experimental control, the polymer was extracted from the prey culture (without predator) by breaking the cells with a French press. The results of one experiment are shown; the values were reproducible in three separate experiments with standard deviations of <10%. Error bars mean the variation of three technical replicates.