Abstract
The effect of colonial variation and growth at pH 7.2 or pH 6.0 on the surface properties of Neisseria gonorrhoeae was assessed by the use of two-phase partitioning and hydrophobic interaction chromatography. Cells grown at pH 7.2 tended to be both hydrophobic and to possess a slight negative charge. Growth at pH 6.0 appeared to decrease hydrophobicity and to increase the negative surface charge. Possession of a series of outer membrane proteins, termed the colony opacity-associated proteins, did not appear to significantly affect charge or hydrophobicity. Piliated cells tended to have a higher negative charge than nonpiliated variants. They also tended to be less hydrophobic at pH 7.2, but became more hydrophobic at pH 6.0. The implications of these findings are discussed.