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

Table 1 Comparative cell growth and volumetric productivity (protein titre) during recombinant disulphide-bond protein production in oxygen-depleted conditions

Proteins	Cell growth^a and protein titre^b
	Culture to flask volume ratio (Oxygen transfer)			Oxygen level
	5:50^c	10:50	25:50	15%^d	3%
scFv13R4	5.49 ± 0.05	4.35 ± 0.17	2.85 ± 0.05	5.57 ± 0.09	2.43 ± 0.05
scFv13R4	10.78 ± 2.37 mg/L	6.30 ± 0.63 mg/L	4.25 ± 0.49 mg/L	10.40 ± 1.39 mg/L	3.59. ± 0.45 mg/L
scFv13R4CM	5.01 ± 0.12	4.13 ± 0.09	2.83 ± 0.13	4.43 ± 0.05	2.34 ± 0.05
scFv13R4CM	8.29 ± 0.76 mg/L	7.13 ± 1.01 mg/L	4.72 ± 0.88 mg/L	9.15 ± 1.39 mg/L	2.35 ± 0.40 mg/L
RNase A	3.65 ± 0.09	2.56 ± 0.00	1.84 ± 0.08	2.93 ± 0.05	1.92 ± 0.00
RNase A	3.24 ± 0.49 mg/L	3.14 ± 0.50 mg/L	2.27 ± 0.29 mg/L	4.55 ± 0.60 mg/L	2.63 ± 0.41 mg/L
NGRP	8.87 ± 0.46	5.33 ± 0.17	3.31 ± 0.09	4.83 ± 0.17	2.51 ± 0.05
NGRP	12.65 ± 2.11 mg/L	8.83 ± 0.40 mg/L	3.66 ± 0.78 mg/L	5.88 ± 1.40 mg/L	2.99 ± 0.52 mg/L

^aFinal cell density was measured as Abs₆₀₀ (Final OD₆₀₀) 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
^c5, 10, and 25 ml of cell culture were grown in 50 ml shake flask to have culture with different culture to flask volume ratio
^dVariation in oxygen level was performed by growing the cells in 24-well plate incubated in hypoxic chamber exposed to 3% O₂ (hypoxic) or 15% O₂ (normoxic). The change (increasing or decreasing) of cell growth and protein titre relative to control (cell cultivation under more oxygenated conditions, 5/50 culture to flask volume ratio or 15% O₂) was analysed by t-test with Welch’s correction (Additional file 2: Table S2 and S3)

ISSN: 1475-2859