Expression and purification of ELP-intein-tagged target proteins in high cell density E. coli fermentation

Table 4 Economic comparison of expression conditions

Medium	Scale	Medium cost (per L)	Yield (mg/L)	Final OD₆₀₀	Media cost per mg protein	Time¹
NBS/Feed 5 (Lab scale)	2.25 L fed batch² fermentation	$38.52	236³	150	16.3 ¢	43-46 hours
NBS/Feed 5 (Bulk scale)	2.25 L fed batch² fermentation	$12.96	236³	150	5.5 ¢	43-46 hours
TB* (Lab scale)	1.5 L batch fermentation	$16.48	34.5⁴	25	47.8 ¢	8-12 hours
TB* (Bulk scale)	1.5 L batch fermentation	$14.47	34.5⁴	25	41.9 ¢	8-12 hours
TB* (Lab scale)	50 mL shake flask	$16.48	109⁴	12.8	6.6 ¢	24-28 hours

¹Time reported is total time from inoculation to harvest.
²Fed batch fermentations consisted of a 1.5 L batch phase in NBS media, followed by 750 mL Feed 5 added during the fed batch and induction phases.
³Target protein was OPH-S5
⁴Target protein was β-gal

ISSN: 1475-2859