BG-11 concentrate

*This formulation has been modified from the original.

Reference: Rippka, R., Deruelles, J., Waterbury, J., Herdman, M., & Stanier, R. (1979). Generic assignments, strain histories and properties of pure cultures of cyanobacteria. Journal of General Microbiology. 111, 1-61. doi:10.1099/00221287-111-1-1Ìý

This concentrate is used for most freshwater cyanobacteria.

Stock Substance Primary stock (g/L) Volume used to prepare 100 mL concentrate Concentrated stock (g/L) Final concentration in medium (mg/L) (adding 50 mL/L)
Ìý Purified H2O – 66 mL – –
1. NaNO3 150 20 mL 30 1500
2. K2HPO4 30 2 mL 0.6 30
3. MgSO4•7H2O 75 2 mL 1.5 75
4. CaCl2•2H2O 36 2 mL 0.72 36
5. Citric Acid 6 2 mL 0.12 6

Ferric Citrate or Ferric Ammonium Citrate a

 6 2 mL 0.12 6
6. Na2EDTA•2H2O 1 2 mL 0.02 1
7. Na2CO3 20 –b –b 20
8. Trace metal solution See below for concentrations 2 mL See below for concentrations See below for concentrations
9. f/2 vitamin solution See below for concentrations 2 mL See below for concentrations See below for concentrations

aNOTE:ÌýOriginal recipe called for the use of Ferric Ammonium Citrate at same rate as Ferric Citrate. Ferric Citrate (used by CPCC) appears to be an acceptable substitute.

bNOTE:ÌýThe NaCO3 stock solution that is normally added to BG-11 medium is excluded from the concentrate as it precipitates out. Add this stock separately (at a rate of 1 mL/L) during preparation of the medium.

Trace metal solution

Substock Substance Primary stock (g/L) Concentration (g/L) Final concentration in medium (mg/L)
1. H3BO3 2.86 0.286 2.86
2. MnCl2•4H2O 1.81 0.181 1.81
3. ZnSO4•7H2O 0.222 0.022 0.222
4. Na2MoO4•2H2O 0.390 0.039 0.390
5. CuSO4•5H2O 0.079 0.0079 0.079
6. Co(NO3)2•6H2O 0.049 0.0049 0.049

f/2 vitamin solution

Substock Substance Primary stock (g/L) Concentration (g/L) Final concentration in medium (mg/L)
1. Vitamin B12 (Cyanocobalamin) 0.001 0.0001 0.001
2. Biotin 0.001 0.0001 0.001
3. Thiamine 0.200 0.0200 0.200

To prepare concentrate:

To make 100 mL of concentrate, combine stocks solutions, in the order listed above, to make 100 mL total volume (will prepare 2L of BG-11 medium). Concentrate may be stored in the fridge in the dark until needed.

To prepare medium:

The final concentrations shown above are to prepare a 100% BG-11 medium by adding 50 mL of the concentrate plus 1 mL of Stock 7 to 949 mL of purified water (e.g., distilled, Nanopure, Milli-Q). Stir, pH adjust to 7.5 if necessary with 1N HCl or 1N NaOH. If sterile medium is needed, then the final medium may be filter-sterilized through a 0.22 um filter and dispensed aseptically into sterile vessels or autoclaved directly in the vessels. Prepared medium may be stored in the fridge in the dark until needed.