We detected the accumulation of non-polar granules in Aphanocapsa sp. to seek for the possibility of
PHB accumulation using nile red fluorescent staining. The nile red dye can bind to the group of nonpolar
molecules including PHB. Under normal light microscope, cells exhibited spherical shape and
multiple cells are aggregated together (Fig.1A). Under fluorescent light, Aphanocapsa sp. exhibited
the nile red signal (golden light) as many granule-like structures throughout the cells (Fig.1B). Thus,
Aphanocapsa sp. accumulated granules of non-polar molecules. Whether these non-polar granules
are PHB, was addressed in the next section.