| Genus | Species Num | Strain Num | SOURCE |
|---|---|---|---|
| Sulfurihydrogenibium | 2 | 2 | HMP |
| Sulfurimonas | 2 | 2 | HMP |
| Sulfurospirillum | 1 | 1 | HMP |
| Sulfurovum | 1 | 1 | HMP |
| Sutterella | 2 | 3 | MGYG |
| Symbiobacterium | 1 | 1 | HMP |
| Synechococcus | 14 | 14 | HMP |
| Synechocystis | 1 | 1 | HMP |
| Syntrophobacter | 1 | 1 | HMP |
| Syntrophomonas | 1 | 1 | HMP |