. 2011 Mar 21;2:44. doi: 10.3389/fmicb.2011.00044

Table 2.

Basic properties of haloalkaliphilic SOB from soda lakes.

Property	Thioalkalimicrobium spp.	Thioalkalispira microaerophila	Thioalkalivibrio spp	Thioalkalibacter halophilus
Number of validated species^*	4	1	9	1
Close relative	Thiomicrospira pelophila	No	Ectothiorhodospira	Halothiobacillus
Cell morphology	Rods and spirilla	Spirilla	Rods, vibrios, spirilla, and cocci	Rods
Sulfur compounds oxidized	HS−, S_n²⁻, S₂O₃²⁻	HS−, S_n²⁻, S₂O₃²⁻	HS−, S_n²⁻, S₂O₃²⁻, S₈, SO₃²⁻, S₄O₆²⁻, SCN⁻	HS⁻, S_n²⁻, S₂O₃²⁻
Electron acceptors	O₂	O₂ microaerophile	O₂, ${NO}_{3}^{-}, {NO}_{2}^{-},$ N₂O	O₂
pH optimum	9.5–10.0	10.0	10.0–10.2	8.5
Upper salt limit	1.5 M Na⁺	1.4 M Na⁺	4.3 M Na⁺	3.5 M Na⁺
Maximal specific growth rate	0.33 h⁻¹	0.08 h⁻¹	0.25 h⁻¹	0.22 h⁻¹
Maximal growth yield with $S_{2} O_{3}^{2-}$	3.5 mg protein mmol⁻¹	5.8 mg protein mmol⁻¹	6.5 mg protein mmol⁻¹	3.5 mg protein mmol⁻¹
Rate of HS⁻ oxidation	Extremely high	Low	Low	High
Dominant compatible solute	Ectoine	nd	Glycine betaine	Ectoine
Yellow membrane pigment	–	+	+	–
nifH	–	+	–	–
Distribution	Asia, Africa, North America	Egypt	Asia, Africa, North America	Asia, North America

*Up to date.