FACTORS AFFECTING FLOCCULATION OF BACTERIA BY CHEMICAL ADDITIVES

Pure bacterial cultures can be flocculated by a variety of chemical flocculants. Flocculation of bacteria will assist in their recovery, especially where the cells themselves are of interest, as in microbial protein production. Studies with several genera of bacteria indicate that the mechanism of flocculation is highly complex. Such interacting variables as temperature, ionic environment, physiological age, flocculant, bacterial genus, and surface shear have been observed. Jar test experiments with washed cells indicate that many of the variables are related to the release by the cell of proteins, nucleic acids, or polysaccharides. When released, these polymers may increase the required dosage of flocculant for recovery as in the case of E. coli, or the dosage may decrease as it does for Lactobacillus. Copyright © 1969 John Wiley & Sons, Inc.