ISP2

International Streptomyces Project-2 Medium (ISP-2)

ISP-2 is a rich medium that is routinely used for cultivating Streptomyces lydicus along with various other plant root associated strains. It contains malt extract and yeast extract, with dextrose as a carbon source; exact composition will vary between batches.

Many Streptomyces spp. grow well on ISP-2, but developmental and/or antibiotic production phenotypes may differ compared to growth on other media (e.g. SFM).

Preparation

Per Litre:

• 4 g Yeast extract powder
• 10 g Malt extract powder
• 4 g Dextrose
• 20 g Agar
• 1 L dH₂O

Instructions

1. For solid medium, add 2g of Agar to each flask
2. Add the rest of the components to a beaker with the dH₂O
3. Add 100ml to each flask
4. Autoclave

Uses

• Streptomyces maintenance
• Spore titres
• Re-isolation experiments
• Selection for resistance to salt-sensitive antibiotics

Notes

For growth in liquid culture, ISP-2 can be made without the agar.