Reference: Rippka, R., J. Deruelles, J. Waterbury, M. Herdman and R. Stanier. 1979. Generic assignments, strain histories and properties of pure cultures of cyanobacteria. J. Gen. Microbiol. 111: 1-61.
This medium is used for successfully for most cyanobacteria. Vitamin B12 may be added for those species that require it. The CPCC adds f/2 vitamin solution to the BG-11 medium for all strains.
| Stock | Substance | Concentration | Amount added to medium (mL/L) |
|---|---|---|---|
| 1. | NaNO3 (omitted for heterocystous species) |
150 g/L | 10 mL |
| 2. | K2HPO4•3H2O or *K2HPO4 | 40 g/L or *30 g/L | 1 mL |
| 3. | MgSO4•7H2O | 75 g/L | 1 mL |
| 4. | CaCl2•2H2O | 36 g/L | 1 mL |
| 5. | Citric Acid | 6 g/L | 1 mL |
| Ferric Citrate | 6 g/L | ||
| 6. | Na2EDTA•2H2O | 1 g/L | 1 mL |
| 7. | Na2CO3 | 20 g/L | 1 mL |
| 8. | Trace metal solution | See below | 1 mL |
| 9. | f/2 vitamin solution | See below | 1 mL |
Adjusting the pH of the medium to approximately 7.5 will avoid heavy precipitation. (Initial pH is approximately 8.5.) When making solid media, you can add agar directly to medium. Omit NaNO3 for media used to culture heterocystous cyanobacteria e.g. Nostoc, Anabaena in order to maintain their ability to continue to produce the heterocysts.
Option: 0.5 g/L of HEPES buffer can be added to the final medium as a buffer. FeCl3 and EDTA added in a 1:1 ratio may be substituted.
Trace metal solution
| Substance | Concentration (g/L) |
|---|---|
| 1. H3BO3 | 2.86 g |
| 2. MnCl2•4H2O | 1.81 g |
| 3. ZnSO4•7H2O | 0.222 g |
| 4. Na2MoO4•2H2O | 0.390 g |
| 5. CuSO4•5H2O | 0.079 g |
| 6. Co(NO3)2•6H2O | 0.0494 g |
Add each substance in the order that they appear here and ensure that each is visually dissolved prior to adding the next on the list. After all substances have been added the stock solution should be topped up with purified water to 1000 mL.
f/2 vitamin solution
Substock solutions:
First prepare separate substock solutions of cyanocobalamin (Vitamin B12) and biotin in purified water (e.g., Milli-Q, Nanopure, distilled water).
| Substock | Substance | Concentration |
|---|---|---|
| 1. | Vitamin B12 (Cyanocobalamin) | 10 mg/10 mL |
| 2. | Biotin | 5 mg/50 mL |
Working stock solution:
Then prepare the final working solution by combining the following amounts of the two substock solutions plus thiamine HCl to 100 mL of purified water.
| Substance | Concentration (per 100 mL) |
|---|---|
| 1. Vitamin B12 (Cyanocobalamin) | 0.1 mL |
| 2. Biotin | 1.0 mL |
| 3. Thiamine HCl | 20 mg |
Dispense the working solution as 1 mL aliquots in cryovials for convenient use when preparing the medium. Store the remainder of the primary stocks and working solution in polyethylene bottles. Wrap vials/bottles with Parafilm to avoid moisture loss and store all solutions frozen.
References: Guillard and Ryther 1962, Guillard 1975