Table 1.

Characteristics of Hbt. salinarum strains.

Strains	Plasmids and vac regions	Vac phenotype	Presence of tfb and tbp	Reference
PHH1 Vac+	pHH1, 150 kbp; p-vac mini-chromosome *; c-vac	spindle-shaped gas vesicles from p-vac in all stages of growth	tbp: A, B, C::ISH, D, E, F	[12,19]
			tfb: A, B, D, F, G	[25,26]
PHH4 Vac+	pHH4, 35 kbp; mini-chromosome*; c-vac	cylinder-shaped gas vesicles from c-vac in the stationary growth phase	tbp: E	[24,27]
			tfb: A,B,D,F,G	[25,26]
NRC-1 Vac+	pNRC100, 190 kbp; gvp1 pNRC200, 354 kbp; contains gvp1 and gvp2	spindle-shaped gas vesicles from gvp1 in all stages of growth	tbp: A, B, C, D, E, F	[22]
			tfb: A, B, C, D, E, F, G; C + E on pNRC200	[22]
R1 Vac−	pHS1, 147 kbp; p-vac::ISH3 pHS3, 284 kbp; c-vac pHS2, 195 kbp; pHS4, 40 kbp	Vac− phenotype due to an ISH3 insertion upstream of gvpA in p-vac	tbp: A, B::ISH, C, D, E, F::ISH	[16]
			tfb: A, B, C, D, E, F, G, H	[16]

* Plasmids or mini-chromosomes in PHH1 were described as the “cccDNA population” [19].