TABLE 1.
Properties of the reference strains of obligately autotrophic sulfur-oxidizing bacteria belonging to the genus Thioalkalivibrio used in comparisons with the thiocyanate-utilizing autotrophic alkaliphilic isolates
| Thioalkalivibrio reference straina | Morphology
|
Nitrate reduction | Oxidation of trithionate | Use of thiocyanate as N source | Membrane-bound yellow pigment | Growth in the presence of 1.5 to 4 M Na+ | DNA G+C content (mol%)b | ||
|---|---|---|---|---|---|---|---|---|---|
| Vibrios | Spirilla | Rods | |||||||
| AL 2 | + | − | + | + | − | − | 63.7 ± 0.5 | ||
| ALJ 6 | + | − | − | − | − | − | 63.9 ± 0.5 | ||
| ALJ 10 | + | − | − | − | − | − | 65.0 ± 0.5 | ||
| ALJ 12 | + | + | − | + | − | − | 62.1 ± 0.5 | ||
| ALJ 15 | + | − | − | + | + | + | 64.9 ± 0.5 | ||
The general properties of the genus Thioalkalivibrio are as follows: obligately autotrophic alkaliphilic sulfur-oxidizing bacteria that are able to grow with sulfide and thiosulfate at pH 7.5 to 10.6 (optimum pH, approximately 10.0) and at salt (total Na+) concentrations of 0.3 to 4 M; strains oxidize sulfide, thiosulfate, sulfur, polysulfide, tetrathionate (some strains oxidize tri- and pentathionates), and sulfite to sulfate at pH values up to 11 to 11.5; and member of the gamma-Proteobacteria, whose nearest relatives are the purple sulfur bacteria belonging to the genus Ectothiorhodospira (39).
Determined by the melting temperature method.