Acid stress response and protein induction in Campylobacter jejuni isolates with different acid tolerance

Table 1 Components of modified chemically defined broth (CDB) for Campylobacter jejuni

Components	Stock solution (mg/ml)	Vol stock solution (ml) for 1 liter	Final conc (mmol/l) of 1xCDB
Buffer solution (10X)		100.0
K₂HPO₄	34.8		20.0
KH₂PO₄	27.2		20.0
Salt solution (20X)		50.0
NaCl	116.0		100.00
K₂SO₄	20.0		5.74
MgCl₂, 6 H₂O	8.2		2.02
NH₄Cl	4.4		4.11
EDTA	0.074		0.01
Amino acid mix 1 (100X)		10.0
L-Arginine HCl	15.0		0.71
L-serine	5.0		0.48
L-leucine	9.0		0.69
L-isoleucine	3.0		0.23
L-valine	6.0		0.51
L-proline	5.0		0.43
L-phenylalanine	5.0		0.30
L-alanine	10.0		1.12
L-histidine	5.0		0.32
L-threonine	5.0		0.42
L-lysine	5.0		0.30
L-glycine	2.5		0.33
L-trypthophan	8.0		0.39
Amino acid mix 2 (10X)		100.0
L-aspartate	5.0		3.76
L-glutamate	13.0		8.83
Individual amino acids
L-cysteine/HCl †	17.5	3.0	0.35
L-cysteine †	12.0	3.5	0.15
L-methionine	14.9	1.0	0.10
Vitamin mix (50X)		0.2
NAD	10.0		0.0030
Thiamine HCl (Vitamine B₁)	10.0		0.0060
Calcium pantothenate (Vitamine B₅)	10.0		0.0040
Individual components
Oxaloacetate, 2 H₂O (10X)	2.5	100.0
NaHCO₃ (2000×)	84.0	0.5	1.49
Biotin (Vitamine H) (500X)	0.25	2.0	0.50
Fe(NO₃)₃, 9 H₂O (1000X)	4.0	1.0	0.0021
CaCl₂, 2 H₂O (1000X)	37.0		0.01
			0.25
Total (ml)		372.2
MilliQ water (ml) *		627.8

The broth was prepared as described in the text.
*: To make portions of 500 ml 2 × CDB without methionine and cysteine, only 127.8 ml of MilliQ water was added. The batches were sterilized by filtration, aliquoted, and stored at −20°C.
†: Cysteine was prepared freshly and dissolved in 1 M HCl prior to each experiment.