A Study of oxygen transfer in the fermentation of E. coli

Abstract

In this work, the effect of oxygen transfer On the growthOfE. coli was studied. E.coli was grown in a glucose media usinga ten liter fermentor equipped with a flat blade impeller. Theprocess wariables chosen for the stll':~~{ were stirrer speedwhich was varied between 200 RPM and 800 RPM, and air flow ratewhich was varied between 1 .. 5 It/min and 10 It/min. Dry weightsof mycelial cells, and dissolved oxygen concentrations weremeasured.The results of the dry weight measurements showed that themycelium formed was dependent on the rate of agitation for anyone aeration level. The growth of E.coli increased with increasingstirrer speed, and at high agitation level heavy myceliumwas obtained.The data of the dissolved oxygen concentration obtainedin this work was used to evaluate an oxygen transfer coefficient`kLa`. From the resulting data a correlation between thekLa values and the system variables was derived. This correlationgave the following equation.