to a flask with 30 ml l lysine solution the experiments ran overnight 16 to 20 h the samples were filtered and the zeolite free supernatant liquid analyzed by means of an hplc system the adsorption experiments were carried out at room temperature and at 35 u00b0 c and 60 u00b0 c the quantities adsorbed were found by analysis of the lysine concentration at the start c 0 and at the end c f of the experiment the remaining difference is adsorbed with the knowledge of the adsorbent concentration c z g zeolite g amino acid in the solution the loading x can be determined equ1 fig1 shows the adsorption isotherms of l lysine monohydrate the solutions used had together with zeolite an average ph value of 9 5 between h zsm 5 and h mordenite no differences are detectable on both zeolites a maximum loading of about 8 is reached the loading of day under the same conditions t 21 u00b0 c reaches a maximum of about 13 experiments at 35 u00b0 c and 60 u00b0 c show that temperature increases have no effect on the adsorption analogous adsorption experiments were carried out with dl and l methionine and l threonine the results are shown in fig2 and 3 the ad and desorption properties of l lysine were also investigated in a fermentation broth the experiments were carried out in shaker flasks with zeolite powder and in the fixed bed column with molded zeolite bodies at various ph values fig4 a sample of about 4 l was withdrawn from a running fermentation and there were added to it immediately afterwards the antibiotic chloramphenicol 0 04 g l and the antimycotic pimaricin 0 01 g l and the mixture was stored.