Modified Acid Medium (MAM) concentrate

*This formulation has been modified from the original.

Reference: Olaveson, Mary M. and Pamela M. Stokes. 1989. Responses of the acidophilic alga Euglena mutabilis (Euglenophyceae) to carbon enrichment at pH 3. Journal of Phycology. 25: 529-539.

This medium is used for freshwater Euglena spp.

Stock Substance Primary stock (g/L) Volume used to prepare 100 mL concentrate Concentrated stock (g/L) Final concentration in medium (mg/L) (adding 100 mL/L)
  Purified H2O – 46.5 mL – –
1. (NH4)2SO4 50 10 mL 5.0 500
2. CaCl2•2H2O 1 10 mL 0.1 10
3. MgSO4•7H2O 50 10 mL 5.0 500
4. KH2PO4 30 10 mL 3.0 300
5. NaCl 3 10 mL 0.3 30
6. Na2EDTA•2H2O 20 0.5 mL 0.1 10
7. Trace metal solution See below for concentrations 1 mL See below for concentrations See below for concentrations
8. FeSO4•7H2O 4.98 1 mL 0.498 4.98
H2SO4 (concentrated) 1.0 mL 0.1 mL/L
9 f/2 vitamin solution See below for concentrations 1 mL See below for concentrations See below for concentrations

Trace metal solution

Substock Substance Primary stock (g/L) Concentrated stock (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. NaMoO4•5H2O 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) Concentrated stock (g/L) Final concentration in medium (mg/L)
1. Vitamin B12 (Cyanocobalamin) 0.001 0.00011 0.001
2. Biotin 0.001 0.00011 0.001
3. Thiamine 0.200 0.022 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 1L of MAM 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% MAM medium by adding 100 mL of the concentrate to 900 mL of purified water (e.g., distilled, Nanopure, Milli-Q). Stir, pH adjust to 3.5 if necessary with 1N HCl or 1N NaOH (initial pH will likely be ~4-4.5). 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.