Time-resolved amino acid uptake of Clostridium difficile 630Δerm and concomitant fermentation product and toxin formation

Table 4 Product formation in MDM

Product	t_{first detection}	t_{halfmaximal production}	Maximal relative production rate
	min	min	h⁻¹
Formate	30	202 ± 18	0.16 ± 0.02
2-hydroxyisocaproate	135	225 ± 12	0.21 ± 0.02
Isocaproate	90	239 ± 14	0.14 ± 0.01
Isobutanoate	135	258 ± 39	0.12 ± 0.02
Isovalerate	30	280 ± 9	0.13 ± 0.02
2-methylbutanoate	30	290 ± 43	0.11 ± 0.01
5-aminovalerate	210	360 ± 8	0.21 ± 0.02
2-oxoisocaproate	280	435 ± 16	0.15 ± 0.02
Alanine	280	442 ± 18	0.18 ± 0.01
Acetate	280	457 ± 20	0.12 ± 0.01
Ammonium	traces in medium	470 ± 49	0.11 ± 0.01

All compounds with the exception of formate and ammonium were detected by GC-MS; formate and ammonium were quantified by enzymatic assays (see Methods), total sampling range up to 720 min, for detailed fits, see Additional file 2

ISSN: 1471-2180