TABLE 2.

Characteristics of generated overexpression strains compared to those of parental strain IK-1^c

Strain	Genotypeb	No. of measured crystals	Mean crystal size (nm) ± SD	Mean Cmag ± SD	Increase in crystal size (%)a	P value for statistical analysis of differences in crystal sizea	Mean no. of crystals per cell ± SD	Increase in no. of crystals (%)a	P value for statistical analysis of difference in crystal no.a	Mean iron content (% of dry wt) ± SDa	Mean cell length (μm) ± SD
IK-1	1× MAI	390	36.2 ± 11.0	0.8 ± 0.2			33.9 ± 10.3			3.9 ± 0.2d	4.4 ± 1.3
2×GFDCop	2× mamGFDC operon	424	44.9 ± 13.5	0.9 ± 0.03	24.0	<1.0E−5	36.3 ± 12.4	7.1	<0.303	7.4 ± 1.1	ND
2×mms6op	2× mms6 operon	616	45.7 ± 14.2	0.9 ± 0.03	26.2	<1.0E−5	46.5 ± 14.3	36.8	<1.3E−6	14.9 ± 2.9	4.5 ± 1.6
2×mms6op+2×GFDC	2× mms6 2× mamGFDC operon	483	45.1 ± 12.2	0.9 ± 0.01	24.6	<3.4E−5	45.1 ± 14.3	32.7	<8.2E−6	14.1 ± 1.9	ND
3×mms6op	3× mms6 operon	1,183	47.9 ± 12.8	1.0 ± 0.2	32.3	<1.0E−5	54.3 ± 29.9	59.5	<7.2E−7	34.8 ± 2.5	4.6 ± 1.5
4×mms6op	4× mms6 operon	665	44.4 ± 13.2	1.0 ± 0.03	22.6	<1.0E−5	57.8 ± 26.9	69.7	<4.2E−10	38.8 ± 2.5	5.1 ± 1.9
5×mms6op	5× mms6 operon	545	41.9 ± 12.0	0.9 ± 0.1	15.7	<1.0E−5	46.0 ± 14.8	35.3	<9.5E−7	ND	5.3 ± 1.7
2×mamABop	2× mamAB operon	436	34.0 ± 17.6	1.0 ± 0.04	−6.1	<0.05	73.4 ± 43.1	115.2	<1.5E−9	0.4 ± 0.5	4.8 ± 1.8
3×mamABop	3× mamAB operon	477	35.6 ± 15.4	0.5 ± 0.1	−1.6	<0.05	68.8 ± 13.2	102.9	<1.5E−9	9.4 ± 0.5	6.0 ± 2.6
2×ABG6Xop	2× mamGFDC 2× mms6 2× mamAB 2× mamXYZ operon	708	38.7 ± 11.9	0.8 ± 0.1	6.9	<1.0E−5	74.5 ± 34.9	118.3	<9.8E−15	140.7 ± 2.4	5.1 ± 2.1
2×AG6X+2×feo	2× mamGFDC 2× mms6 2× mamAB 2× mamXYZ operon 2× feoAB operon	697	41.1 ± 8.4	0.7 ± 0.2	13.5	<0.00001	69.3 ± 13.4	104.4	<1.5E−15	135.9 ± 6.4	ND

^aCompared to IK-1.

^bWith respect to magnetosome genes.

^cND, not determined.

^dCompared to WT.