TABLE 3.

Descriptive statistics for PHA granules of P. oleovorans GPo1000 and GPo1001 determined by analysis of electron micrographs^a

Strain	No. of cellsb	No. of PHA granulesc	rgnd (calculated) (μm)		Parameter determined	Parameter value			PHA (%, wt/wt) determined by:
									EMh		GC measurements
			x	y		Range	Mean	Median	Mean	Median
GPo1000	22	31	0.1–0.4	0.09–0.55	vgn (μm3)e	0.003–0.4	0.1	0.1
	23	38			gn/cellf	1–5	2	1
	23	32			(vgn × gn/cell)/vcellg	12–75	47	49	75.6	77.1	54.9
GPo1001	14	46	—i	0.02–0.19	vgn (μm3)	4 × 10−05–0.03	0.003	0.0002
	52	280			gn/cell	0–15	5	5
	14	46			(vgn × gn/cell)/vcell	0–13	4	2	12.7	6.7	9.6

^aCultures of P. oleovorans GPo1000 and GPo1001 were grown on 0.1NE2 minimal medium containing 15 mM octanoate. Cells from stationary-phase cultures were prepared for electron microscopy as described in Materials and Methods. For each sample, 13 independent electron micrographs, each showing one or more bacterial cells, were chosen for analysis. 

^bOnly sharply and completely depicted cells were chosen. 

^cOnly sharply and completely depicted granules were chosen. 

^dRadius of PHA granules, calculated by multiplying the measured diameter factor (x, length; y, width) by the electron microscopy magnification. 

^eAverage volume per PHA granule. 

^fNumber of PHA granules per cell. 

^gVolume of PHA granules (average volume per PHA granule times number of granules per cell) per cell volume (percent). 

^hCalculated from micrographs, assuming a density of 1.05 g/ml and a conversion factor from cell volume to cell dry mass of 0.3. 

ⁱ—, not determined, since PHA granules were spherical (assumption: a = b).