Dictylostelium discoideum Growth Media

For more than 50 years this slime mold has been used as a model for studying development. The cellular slime mold, D. discoideum, resides in the phylogenic order, Acrasiales, within the phylum Myxomycophyta and, as an organism, represents a junction between single and multi-cellular organisms. Its genomic content is approximately four times that of S. cerevisae, with about 50 Mb of low GC content (20%) DNA in 6 chromosomes. D. discoideum has at least 14 described naturally occurring plasmids. Along with shuttle vectors, homologous recombination, insertional mutagenesis, and transformation competence, this creature combines many ingredients necessary for functional analysis. In addition, exotic heterologous eukaryotic proteins expressed in D. discoideum are exported to the media correctly folded and glycosylated, making this organism a candidate host for properly expressed mammalian proteins.

As a meat eater, D. discoideum grows voraciously as autonomous cells when the bacterial food source is plentiful, but when the food source is depleted, seeks and joins forces with others to make multi-cellular structures and eventually forms fruiting bodies containing spores to maximize the probability of continuity during times of scarce food. This life style makes this organism a popular model for the study of cell-cell interactions and development.

D. discoideum can be grown on agar plates in SM Medium with bacteria as the food source. On SM Agar plates bacteria feed and grow on the nutrient medium and D. discoideum feed on the bacteria. An SM agar plate is seeded with bacteria (Aerobacter aerogenes or Escherichia. coli) and a few D. discoideum cells. The cells, feeding and dividing on the bacterial lawn, form colonies of growing cells. As each colony grows, the individual slime mold amoeba in the center, where bacteria are depleted, join to form multicellular fruiting bodies. The process takes 3-4 days from plating to fruiting body formation.

SM Medium
25 g/liter Contents/L: 1.9 g KH2PO4, 1.3 g K2HPO4.3H2O, 1 g MgSO4.7H2O, 10 g glucose, 10 g bactopeptone, 1 g yeast extract.
Powder
	227 g (0.5 lb)	3090-112
	454 g (1.0 lb)	3090-122
	1 kg (2.2 lb)	3090-132
	5 kg (11.0 lb)	3090-142
Pouch, 1 liter (25 g):
	1 ea	3090-125
	pack (10 x 1 ea)	3090-175
	case (10 x packs)	3090-195

SM Agar Medium
42 g/liter Contents/L: SM Medium, 17 g Agar-B.
Powder
	227 g (0.5 lb)	3092-212
	454 g (1.0 lb)	3092-222
	1 kg (2.2 lb)	3092-232
	5 kg (11.0 lb)	3092-242
Pouch, 1 liter (42 g):
	1 ea	3092-225
	pack (10 x 1 ea)	3092-275
	case (10 x packs)	3092-295

Specific strains of D. discoideum are capable of growing axenically (without bacteria as food) in liquid culture on HL5, a non-defined medium.

HL5 Medium
22 g/liter Contents/L: 0.5 g KH2PO4, 0.5 g Na2HPO4, 7 g yeast extract, 14 g proteose peptone.
Powder
	227 g (0.5 lb)	3090-212
	454 g (1.0 lb)	3090-222
	1 kg (2.2 lb)	3090-232
	5 kg (11.0 lb)	3090-242
Pouch, 1 liter (22 g):
	1 ea	3090-225
	pack (10 x 1 ea)	3090-275
	case (10 x packs)	3090-295

HL5 Medium w/Glucose
35.5 g/liter Contents/L: HL5, 13.5 g glucose.
Powder
	227 g (0.5 lb)	3090-312
	454 g (1.0 lb)	3090-322
	1 kg (2.2 lb)	3090-332
	5 kg (11.0 lb)	3090-342
Pouch, 1 liter (22 g):
	1 ea	3090-315
	pack (10 x 1 ea)	3090-375
	case (10 x packs)	3090-395

A synthetic defined minimal medium formulation, FM derived from HL5, supports the growth of most strains that will grow on HL5 and is used for transformations and gene disruption studies. The original formulation [Franke and Kessin (1977) PNAS, USA 74,2157] has been adapted to a single powder mixture that is added to water and autoclaved. Growth of Axenic strains AX3 and AX4 grown for 15 generations on this media, versus FM made according to traditional methods, demonstrated identical growth rates. It is, however, recommended that this media be sampled (2 x 1 Liter pouches are offered at no charge, see below) and tested for growth with different strains and growth conditions.