Delft medium

Verduyn C, Postma E, Scheffers WA, Van Dijken JP: Effect of benzoic acid on metabolic fluxes in yeasts: a continuous-culture study on the regulation of respiration and alcoholic fermentation. Yeast 1992, 8:501–517.

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delft salt solution

Component	c (g/L)
(NH4)2SO4	5
KH2PO4	3
MgSO4 * 7H2O	0.5

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IMPORTANT MgSO4 has to be autoclaved separately!

Example: Making 1L of a 5x salt solution

Soln A

500 mL final volume
25g (NH4)2SO4
15g KH2PO4
add about 400mL deionized water
set pH to 5.5 with conc NaOH
Add deionized water to 500 mL
Autoclave 121C 20 min

Soln B

500 mL final volume
2.5g MgSO4 * 7H2O
Add deionized water to 500mL 
It is not necessary to set pH of this solution
Autoclave 121C 20 min

After autoclaving, combine A and B to form one liter of 5x delft salt solution

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Vitamin solution x1000

Component	c (g/L)
Biotin	0.05
Ca-pantothenate	1.0
Nicotinic acid	1.0
Thiamine-HCl	1.0
Pyridoxine-HCl	1.0
p-aminobenzoic acid	0.2

Filter sterilize

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Trace element solution x1000

Component	c (g/L)
Na2EDTA	15
ZnSO4 * 7H2O	4.5
MnCl2 * 2H2O	0.84
CoCl2 * 6H2O	0.3
CuSO4 * 5H2O	0.3
Na2MoO4 * 2H2O	0.4
CaCl2 * 2H2O	4.5
FeSO4 * 7H2O	3.0
H3BO3	1.0
KI	0.1

Filter sterilize

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Preparation

Per 1000mL of medium:

• carbon source 100mL (200g/L)
• delft salt solution 100ml (x10)
• 1ml vitamin slution (x1000)
• 1mL Trace element solution (x1000)
• amino acids for auxotrophic requirements
• Water to one liter