Cell adsorption control by culture conditions

Summary Phosphate supply to growingCorynebacterium glutamicum (i.e. their phosphorus content) was found to have a distinct influence on cell wall properties, resulting in a variation of flocculation and adsorption behaviour of the bacteria. Cells saturated with phosphate are hydrophobic and show a high tendency to flocculate and to adsorb on treated glass surfaces due to hydrophobic interactions. Phosphate depletion of the cells leads to a more hydrophilic surface character and a comparatively low ability to flocculate and to adhere. The net surface charge ofC. glutamicum is not much affected by their phosphorus content. As phosphate depletion (down to a phosphorus content of about 20% of the saturation value) was shown to have no influence on growth rate and on specific 1-leucine productivity, the inducible variation of the surface properties ofC. glutamicum can be exploited to control a continuous reactor with adsorbed cells.