body formation, strain GH4 was grown on succinate/PD minimal medium using several IPTG concentrations and then examined by electron microscopy. Strain GH4 did not synthesize polyhedral organelles at 0.1 mM IPTG (Figure 2-4B) and instead rod-like structures were observed which became more prevalent at 1 mM IPTG (Figure 2-4C). In the absence of IPTG, no normally shaped organelles or rod-like structures were formed (Figure 2-4A). A similar phenomenon was noted when complementation of strain GH42 containing a TPOP1 insertion in thepduB gene and carrying plasmid pGH2, encoding the pduB gene was attempted. Aberrant structures were produced at 0.1 mM IPTG (Figure 25B) which became more prevalent at 1 mM IPTG (Figure 2-5B) and no organelles or aberrant structures were observed in the absence of IPTG (Figure 2-5C). The finding that GH4 and GH42 produced aberrant structures in the presence of IPTG but not in its absence suggests that PduA and PduB may play a role in organelle formation. It also suggests that downstream expression from the tetracycline-inducible promoters in the TPOPs is not similar enough to wild type levels to produce a normal appearing organelle. The B12-Dependent Diol Dehydratase is not Required for the Formation of the Polyhedral Organelles

       Strain BE87, containing a nonpolar deletion of the pduCDE genes, was found to be unable to degrade PD using MacConkey and AIM plates and no growth was observed on PD minimal medium plates. The strain was grown on PD/succinate minimal medium and observed using electron microscopy. Polyhedral organelles were observed in this strain (Figure 2-6) and when similarly prepared samples were labeled with polyclonal antibody against diol dehydratase, no diol dehydratase was found to be associated the organelle or the cell (Figure 2-7C). The interiors of the polyhedral organelles of this strain appear