MWC/MWC+Se
(Guillard & Lorenzen 1972, Karin Rengefors pers. com.)
We use the recipe in Guillard et al. (1972), but often use a slight modification according to Rengefors (pers. com.):
TES- is used instead of TRIS buffer and selenium is added.
1. Stock solutions
CaCl2•2H2O | 3.68 g/100 mL |
MgSO4•7H2O | 3.70 g/100 mL |
NaHCO3 | 1.26 g/100 mL |
K2HPO4•3H2O | 1.14 g/100 mL |
NaNO3 | 8.50 g/100 mL |
Na2O3Si•9H2O | 2.84 g/100 mL |
2. Trace element solution
Na2EDTA•2H2O | 4.36 g |
FeCl3•6H2O | 3.15 g |
MnCl2•4H2O | 0.18 g |
H3BO3 | 1.00 g |
1% CuSO4•5H2O | 1 mL |
2.2% ZnSO4•7H2O | 1 mL |
1% CoCl2•6H2O | 1 mL |
0.6% Na2MoO4•2H2O | 1 mL |
dH2O | to 1000 mL |
The pH adjusted to 4-4.5 to retain the solubility of the metals
3. f/2 vitamin solution - vitamin primary stock solutions
Biotin | 0.01g/100 mL |
Cyanocobalamin (B12) | 0.1g/100 mL |
Note: Vitamin B12 and Biotin are obtained in a crystalline form. When preparing the Vitamin B12 Stock Solution
allow for approximately 11% water of crystallization (For each 1.0 mg of Vitamin B12 add 0.89 ml dH2O).
When preparing the Biotin Stock Solution allow for approximately 4% water of crystallization (For each 1.0 mg of Biotin add 9.6 ml dH2O).
Keep the vitamin solutions frozen. Bottles of polyethylene are recommended for storage of vitamins.
4. f/2 vitamin working stock solution
1) Dissolve 20 mg Thiamine HCl (Vitamin B1) in ca. 80 mL dH2O in a 100 mL volumetric flask.
2) Add 1 mL of the biotin primary stock solution.
3) Add 0.1 mL of the cyanocobalamin primary stock solution.
4) Fill with dH2O to 100 mL.
The vitamin working stock solution is divided into to 10-mL lots in polyethylene vials and kept frozen until use.
Preparation of MWC-medium
Add either 115 mg TES-buffer or 50 mL 0.1% Tris-buffer and 1 mL of the stock solutions 1-6, 1 mL trace metals and 0.5 mL f/2 vitamin mix. Adjust pH to c. 7.5.
Autoclave.
MWC+Se
As MWC but add also 1 mL 0.002 g/L Na2SeO3•5H2O.
Reference
Guillard, R.R.L. & Lorenzen, C.J. 1972: Yellow-green algae with chlorophyllide C. J. Phycol. 8:10-14.