Genetic and process engineering strategies for enhanced recombinant N-glycoprotein production in bacteria

Table 3 Comparative cell growth and volumetric production (protein titre) during recombinant disulphide-bond protein production in the wild-type (wt) and ΔdsbB strain supplemented with small molecule oxidant (cystine)

Proteins	Cell growth^a and protein titre
	Wild-type (wt)		ΔdsbB
	0 Cys^c	100 Cys	0 Cys	100 Cys
scFv13R4	4.88 ± 0.08	4.91 ± 0.20	3.08 ± 0.10	3.50 ± 0.05
scFv13R4	5.87 ± 0.21 mg/L	6.89 ± 0.37 mg/L	1.28 ± 0.24 mg/L	2.97 ± 0.14 mg/L
scFv13R4CM	4.45 ± 0.09	4.35 ± 0.09	2.90 ± 0.00	3.65 ± 0.00
scFv13R4CM	6.42 ± 0.70 mg/L	6.15 ± 0.41 mg/L	1.28 ± 0.24 mg/L	3.42 ± 0.81 mg/L
RNase A	3.55 ± 0.05	3.60 ± 0.14	3.12 ± 0.00	3.39 ± 0.05
RNase A	5.64 ± 1.05 mg/L	5.40 ± 0.36 mg/L	0.85 ± 0.12 mg/L	4.07 ± 0.89 mg/L
NGRP	n.d	n.d	3.90 ± 0.00	3.83 ± 0.06
NGRP			6.66 ± 0.77 mg/L	7.46 ± 0.33 mg/L

^aFinal cell density was measured as Abs₆₀₀ recorded 4 h after induction
^bTotal protein titre was determined from the Western blot quantification data (glycosylated and non-glycosylated), normalised and converted from sample OD₆₀₀ of periplasmic fraction and sample volume for Western blot. For the final cell density and protein titre, the average of three biological replicates is shown and the errors indicate standard deviation. cell culture was grown under standard cultivation condition in shake flask 10:50 ml
^cCulture medium was added with or without 100 μM of cystine at the same time with inducers addition. n.d. not determined. The change (increasing or decreasing) of cell growth and protein titre relative to control (production in wt or ΔdsbB strain without cystine supplementation) was analysed by t-test with Welch’s correction (Additional file 2: Table S5)

ISSN: 1475-2859