Effect of colony type and pH on surface charge and hydrophobicity of Neisseria gonorrhoeae

Abstract

The effect of colonial variation and growth at pH 7.2 or pH 6.0 on the surface properties of N. gonorrhoeae was assessed by the use of 2-phase partitioning and hydrophobic interaction chromatography. Cells grown at pH 7.2 tended to be 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 seem to significantly affect charge or hydrophobicity. Piliated cells tended to have a higher negative charge than non-piliated variants. They tended to be less hydrophobic at pH 7.2, but became more hydrophobic at pH 6.0.