Method of removing cells from fermentation broth

摘要

A method for improving the membrane permeation rate under milder pre-treatment conditions when membrane-separating cells from a fermentation broth obtained by culturing a microorganism belonging to the genus Escherichia, characterized in that polyethyleneimine is added to the fermentation broth before the membrane-separation of the cells. The method of the present invention can improve the permeation rate by from 1.5 to 4.0 times, avoiding the need for large-sized equipment, and increasing the efficiency of the membrane permeation equipment.