9.C.9 The Acetobacter aceti Acetate Exporter (AAAE)

Acetate is an end product of ethanol, sugar and sugar alcohol metabolism in Acetobacter aceti. It is pumped out of the cells by a pmf-dependent mechanism. Right side out vesicles pump acetate out while inverted vesicles pump it in (Matsushita et al., 2005). Export occurs best at low pH. It is not known if acetate or acetic acid is the transported substrate, but uncouplers block active transport.

The generalized transport reaction is probably:

acetate (in) + nH+ (in) → acetate (out) + nH+ (out), or

acetic acid (in) + nH+ (in) → acetic acid (out) + nH+ (out)




Matsushita, K., T. Inoue, O. Adachi, and H. Toyama. (2005). Acetobacter aceti possesses a proton motive force-dependent efflux system for acetic acid. J. Bacteriol. 187: 4346-4352.