NUCLEAR-MAGNETIC-RESONANCE RELAXATION STUDIES OF POLY(HYDROXYBUTYRATE) IN WHOLE CELLS AND IN ARTIFICIAL GRANULES

The physical state of poly(hydroxybutyrate) (PHB) in whole cells and i n the form of artificial biomimetic granules has been probed using C-1 3 nuclear magnetic resonance (NMR) spectroscopy. Studies on varying co ncentrations of whole cells of Alcaligenes eutrophus show that changes in the line widths of PHB in whole cells do not correlate with change s in transverse relaxation times. Solid-state magic-angle spinning NMR studies demonstrate that the line broadening results from a reduction in the static field homogeneity rather than from intrinsic properties of the PHB within the cells. Transverse and longitudinal relaxation t imes of PHB in whole cells and in artificial granules are similar, ind icating similarities in structure and mobility.