Benson Lab
Frankia Defined Minimal Medium (FDM)
For routine growth and subculture of Frankia in 500 ml screw-capped flasks.
| Component | Per liter |
| NaSuccinate (CpI1) | 5 g |
| Fructose (EanI1) | 5 g |
| NaPyruvate (CcI3) | 5 g |
| NH4Cl | 0.5 g |
| 20X stock salts* | 50 ml |
| 1000X Iron stock ** | 1 ml |
| 10X Buffer stock *** | 100ml (adjust pH to 6.5; add after autoclaving) |
To make 1 liter of medium, start with 850 ml dH2O, add carbon source and ammonium chloride, 50 ml of the 20X stock salt solution, 1 ml of iron solution and distribute 180 ml each to 500 ml Erlenmeyer flasks. Autoclave the phosphate buffer separately and add 20 ml to each flask after cooling.
*20X Stock Salts: CaCl2.2H2O, 2.0 g; MgSO4.7H2O, 4.0 g; dH2O, 1000 ml
**1000X Stock Iron: Dissolve 0.75 g Na2EDTA.2H2O, 0.56 g FeSO4.7H2O and 0.02 g of Na2MoO4.2H2O in 100 ml dH2O
***10X Buffer: KH2PO4, 68.0 g/l; K2HPO4.3H2O, 114.1 g/l. Separately make up one 1 l of monobasic plus 500 ml of dibasic, add dibasic to monobasic slowly to adjust pH to 6.5.
Notes:
- Proteose Peptone #3 can be added at a level of 0.5 g/l for some growth improvement.
- Although more expensive, MOPS can be substituted for some of the phosphate buffer especially in nitrogen-fixing cultures. In that case, make up a 10X NaMOPS solution to 200 mM, pH6.5 by adding 46 g to 1 liter dH2O and then replacing some of the 10X phosphate. Lower the phosphate to 1 mM (by adding 1.0 ml instead of 20 ml of the 10X P-stock)