Some physical investigations of the behaviour of bacterial surfaces VI. Chemical modification of surface components

1. 1. Cells of Aerobacter aerogenes were chemically modified using p-toluenesulphonyl chloride, fluoro-2,4-dinitrobenzene, diazomethane, methanolic HCl, dicyclohexyl-carbodiimide, N ethyl-5-phenylisoxazolium-3′-sulphonate, ethylene and propylene oxides and ethyleneimine. 2. 2. The electrophoretic mobility of the modified cells was determined on suspensions in solution at various pH values. 3. 3. The infrared spectra of the modified cells was plotted to confirm the type of modification which had occurred. 4. 4. The results indicate that for cells of Aerobacter aerogenes there is no adsorption of ions from the suspension media onto the basic surface matrix, and that their mobility value is largely determined by the surface ionogenic groups, modified by gegenion association. 5. 5. Diazomethane and methanolic HCl were the most suitable reagents for the modification of the carboxyl groups on alcohol-stable surfaces, and fluoro-2,4-dinitrobenzene and p-toluenesulphonyl chloride for amino groups.