Direct measurement of poly(β-hydroxybutyrate) in a pseudomonad by solid-state ¹³C NMR

Four narrow lines are observed in the high-resolution cross-polarization magic-angle spinning ¹³C NMR spectra of intact, lyophilized samples of Pseudomonas sp. LBr, in addition to the broader lines normally associated with bacterial cellular material. These narrow lines arise from poly(β-hydroxybutyrate). The cellular carbon contained in this storage material can be measured quantitatively and nondestructively from the solid-state NMR spectra. We find that cells starved for phosphorus store up to 50% of their total carbon as poly(β-hydroxybutyrate). When such cells are used to inoculate medium containing a source of phosphorus, all of the poly(β-hydroxybutyrate) is metabolized by the time the culture has reached midlogarithmic growth phase.