Table 1.

Components for 50 mL of ZY non-inducing (ZY-NIM) and ZY auto-inducing media (ZY-AIM)

Component	For 50 ml of ZY-NIM	For 50 ml of ZY-AIM
ZY mediaa	45 ml	45 ml
1 M MgSO4b	0.1 ml	0.1 ml
25x M-Salts-1c	2.0 ml	2.0 ml
25 g/L NH4Clb	2.0 ml	2.0 ml
40% (w/v) Glucosed	0.625 ml	-
50x 5052e	-	1.0 ml
5000x Trace Metalsf	10 μl	10 μl

Components were sterilized separately and combined as follows after they are cooled to room temperature and immediately before use.

^aZY Media, per liter: 10 g Tryptone, 5 g Yeast Extract. Autoclave.

^bUnlabeled. Sterile by autoclaving or filtering.

^c25x M-Salts-1: 0.625 M Na₂HPO₄, 0.625 M KH₂PO₄, 0.125 M Na₂SO₄. No pH adjustment. Autoclave.

^d40% (w/v) glucose: 20 g α-D-glucose in total volume of 50 mL. Autoclave or sterile filter.

^e50x 5052, per 500 mL: 12.5 g α-D-glucose, 50 g α -lactose, 125 mL glycerol (or 250 mL of 50% glycerol, which is easier to measure). Note: to get the lactose to dissolve, heat gently in microwave. Once dissolved, lactose will stay in solution indefinitely.

^fNot essential for ZY-NIM, but can help cell growth, as previously described (28).