Three-dimensional label-free visualization and quantification of polyhydroxyalkanoates in individual bacterial cell in its native state
So Young Choi, Jeonghun Oh, JaeHwang Jung, YongKeun Park, Sang Yup Lee
Abstract
Significance Polyhydroxyalkanoates (PHAs) are bacterial polyesters considered as sustainable and environmentally friendly substitutes for petroleum-based plastics. Despite great advances in PHA research, spatiotemporal characteristics of PHA granule formation and distribution in a live bacterial cell are not well understood. Here, we report the results of a three-dimensional (3D) analysis of live bacterial cells accumulating poly(3-hydroxybutyrate) (PHB), the best-studied member of PHAs. Optical diffraction tomography was applied for visualizing individual cells and in vivo PHB granules and quantifying their physical properties such as weight, volume, density, and localization by measuring 3D refractive index distributions. Comparative analyses of native and recombinant PHB-producing strains revealed distinctive characteristics of PHB accumulation, providing insights into spatiotemporal localization of PHA granules in vivo.