A study of polynucleotide phosphorylase production by Escherichia coli in a hollow fibre reactor

A 30-l hollow fibre reactor with continuous fermentation for cell recycling of Escherichia coli AS 1.183 was used to remove the inhibitory effects on cell growth and extend the fast growth phase to increase the yield of polynucleotide phosphorylase (PNPase) in E. coli cells. When the dilution rate was 1.5 h−1, the cell concentration of E. coli reached 235 g/l (wet wt, 70% moisture content), with PNPase activity above 90 u/g (wet wt). With the dilution rate is 1.0 h−1, the fermentor volumetric productivity of PNPase in a hollow fiber reactor can reach 974 (u/h * l) compared to 20 (u/h * l) in a conventional batch culture.