Expression of the human molecular chaperone domain Bri2 BRICHOS on a gram per liter scale with an E. coli fed-batch culture

Table 1 Summary of key parameters for the expression and purification of NT*Bri2 BRICHOS expressed in bioreactor cultivations in this study

Culture	#1	#2	#3	#4	#5	#6	#7	#8	#9^d
Temperature (°C)	30	30	25	25	25	25	25	25	25
Medium	LB	TB	da Silva	Korz	Wyre	da Silva	da Silva	da Silva	da Silva
Substrate in feed			Glycerol	Glycerol	Glycerol	Glycerol	Glycerol	Glycerol	Glycerol
IPTG (µM)	500	500	33	33	33	50	150	500	150
OD₆₀₀ induced	1	0.6	30	13	35	32	25	29	60
OD₆₀₀ harvest	8.4	31	121	50	61	190	106	76	176
Induction time (h)	21	21	15	10	10	20	20	20	22
Total culture time (h)	26	26	39	39	39	47	47	47	49
Culture Size (mL)	400	400	325	274	307	910	900	907	1180
Wet Cell Weight (g/L)	13	32	197	58	81	200	120	82	214^e
Expression level (g/L)^a	0.53	0.82	2.1	2.1	2.7	7.9	7.9	6.2	18.8^f
% of culture purified	100%	100%	25%	100%	50%	9.1%	11.6%	25%	7.1%
Purified (mg)^b	37	73	40	70	92	133	428	510	540
Yield after purification (g/L)^c	0.09	0.18	0.49	0.26	0.60	1.61	4.12	2.25	6.41
% of expression level	17.6%	22.3%	23.8%	11.9%	22.1%	20.4%	51.8%	36.4%	34.1%

^aExpression level of NT*-Bri2 BRICHOS was estimated with SDS-PAGE. See also Additional file 1: Figures S2, S3
^bProtein yield was calculated using Abs₂₈₀ and the protein specific extinction coefficient after NT*-Bri2 BRICHOS was eluted and dialyzed to remove imidazole
^cYield of NT*-Bri2 BRICHOS after purification
^dCulture #9 was repeated 2 more times to estimate the batch-to-batch variation see Additional file 1: Table S1
^eDry cell weight for culture #9 was 82 g/L
^fThe expression level calculated by considering the % of NT*-Bri2 BRICHOS relative to the total protein content and the dry cell mass is 15.2 g/L

ISSN: 1475-2859