The Role of CpsG in Capsular Carbohydrate Accumulation in Response to Aminoglycoside Stimulation

Abstract

Escherichia coli had been shown to increase its capsular polysaccharide (CPS) production upon stimulation with kanamycin and streptomycin. In this study, an attempt was made to investigate whether or not CpsG, a phosphomannomutase responsible for part of the colanic acid synthesis pathway, is involved in such response. Our study showed that upon one hour of kanamycin or streptomycin stimulation, Δ cpsG E. coli was still able to increase its CPS concentration, implying that CpsG might not play a role in such response. Silver staining following PAGE electrophoresis indicated that CpsG was not sufficiently abundant in E. coli to be visible as a difference between the Wild Type and Δ cpsG strains. Absence of CpsG did not affect CPS accumulation as if such accumulation is independent of the CpsG pathway.