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C. Alkaline media for Arthrospira (Spirulina) and alkaliphilic forms
SOTSOT (Schlösser)
Simplified analogue of Zarrouk medium
- Application
- Arthrospira spp.; SAG and IAM collections; routine laboratory maintenance of strains
- pH
- 9.0–9.5
- Source
- Schlösser, 1982 (SAG)
Composition
| Component | Amount per 1 L |
|---|---|
| NaHCO₃ | 16.8 g |
| K₂HPO₄ | 0.5 g |
| NaNO₃ | 2.5 g |
| K₂SO₄ | 1.0 g |
| NaCl | 1.0 g |
| MgSO₄·7H₂O | 0.2 g |
| CaCl₂·2H₂O | 0.04 g |
| FeSO₄·7H₂O | 0.01 g |
| Na₂EDTA·2H₂O | 0.08 g |
| A5 + Co trace element solution | 1.0 mL |
| Vitamin B₁₂ solution | 1.0 mL |
| Distilled water | to 1000 mL |
A5 + Co trace element solution
per 100 mL of solution · usage rate 1 mL per 1 L of medium (sufficient for 100 L) · storage at 4 °C in dark glass, 12 months
| Component | Weighed amount / volume |
|---|---|
| H₃BO₃ | 286 mg |
| MnCl₂·4H₂O | 181 mg |
| ZnSO₄·7H₂O | 22.2 mg |
| Na₂MoO₄·2H₂O | 39.0 mg |
| CuSO₄·5H₂O | 7.9 mg |
| Co(NO₃)₂·6H₂O | 4.94 mg (or 1 mL of a primary stock solution at 4.94 g/L) |
| Distilled water | to 100 mL |
Vitamin B₁₂ solution for SOT
per 100 mL · usage rate 1 mL per 1 L of medium · storage at −20 °C, 6 months
| Component | Weighed amount / volume |
|---|---|
| Cyanocobalamin (B₁₂) | 1.0 mg |
| Distilled water | to 100 mL |
Preparation
The procedure is the same as for Zarrouk medium: separate solutions "A" (bicarbonate + phosphate) and "B" (everything else). The vitamin B₁₂ solution is added to the cooled medium by sterile filtration.
Notes
- It differs from Zarrouk medium in lacking the B6 rare metals solution and in containing vitamin B₁₂; in macronutrient composition the two are practically identical.
- Dissolve the salts one at a time, in the order given; H₃BO₃ dissolves slowly — warming to 40 °C is permissible. Cobalt is added from a primary stock solution: a weighed amount of 4.94 mg cannot be measured on an ordinary balance. Primary Co stock solution: 494 mg Co(NO₃)₂·6H₂O in 100 mL of water, take 1 mL. Without cobalt the solution is simply called "A5". The appearance of a precipitate or turbidity indicates that the solution is no longer usable.
- The final concentration in the medium is 10 µg/L. The solution is not autoclaved; it is added to the cooled medium by sterile filtration.