High cell density media for Escherichia coli are generally designed for aerobic cultivations – consequences for large-scale bioprocesses and shake flask cultures

Table 1 Biomass yield, cell dry weight and side product concentration for E. coli W3110 during the different cultivation types on glucose based mineral salt medium.

Type of cultivation	Addition of trace elements	Y_X/S¹ (g g^-1)		CDW (g L^-1)		Acetate (mM)		Lactate (mM)		Formate (mM)
		Batch²	Fed-batch³	Batch	Fed-batch	Batch	Fed-batch	Batch	Fed-batch	Batch	Fed-batch
Control	+	0.49 (0.01)⁴	n.d.	19.3 (1.1)	n.d.	43.8 (10.1)	n.d.	4.5 (6.3)	n.d.	0.5 (0.7)	n.d.
Control	-	0.48 (0.01)	0.55	18.9 (0.4)	36.4	30.8 (8.4)	29.7	3.8 (3.4)	11.6	1.8 (2.0)	5.0
STR-PFR	+		0.50		37.8		0.1		2.2		0.0
STR-PFR	-		0.45		36.4		4.5		0.0		14.8
Oxygen downshift	+		0.23		20.2		139.7		435.8		0.0
Oxygen downshift	-		0.38		24.7		173.2		60.6		16.9

¹ Yield coefficients were calculated for a time period of 4 hours starting with the feeding start. Here Y_X/S includes also biomass formed from acetate which is consumed during this phase.
² Batch samples were taken at the end of the exponential growth phase.
³ Fed-batch sample was taken 4 h after the feed start.
⁴ Numbers in brackets indicate standard deviations between different cultivations.

ISSN: 1475-2859