New correlation of volumetric oxygen mass transfer coefficient for scale-up in aerobic fermentation of recombination E. coli

Xiao X. Ma1,2, Dai D. Fan1,2*,

Abstract

This paper presents an appropriately available correlation through a series of formula derivations and reasonable simplifications using some hypotheses. Then wide ranges of culture conditions such as gas flow rate , stirrer speed and initial culture volume were correlated with volumetric oxygen mass transfer coefficient and the correlation is determined as: kLa=KQxNyVL -y/3.15. The correlation factors K, x, y for the 12.8 L and 30 L bioreactors calculated by sodium sulfite oxidation method were 0.01, 0.4613, 1.5131 and 0.004, 0.525, 1.685, respectively. The correlation proposed here could guide the scale-up of fermentation to obtain an optimized initial volume of fermentation broth (15.4 L) for 30 L bioreactor form 12.8 L via the criteria of maintaining p*kLa as a constant. The final DCW of 59.7 g L-1 and HLC concentration of 6.25 g L-1 were obtained on the pilot-scale upon maintenance of DO at the same level, resembled to the lab-scale of 80.13 g L-1 and 13.1 g L-1.