Buffering capacity and membrane H+ conductance of acetic acid bacteria

Abstract

Buffering capacities and membrane conductance to H+ were measure in Acetobacter aceti ATCC 15973 and Gluconobacter oxydans ATCC 621 by a pulse technique. In both strains the buffering capacity of intact cells was a significant proportion of the total buffering capacity, but the magnitude of the buffering capacity varied between one species and another. Over the pH range studied, 4.02 to 8.15, Gluconobacter oxydans, which oxidizes sugars and alcohols to acids and accumulates them, showed lower values of buffering capacities and membrane conductance to protons than Acetobacter aceti, which oxidizes these substrates completely to CO2 and H2O. © 1995 Society for Industrial Microbiology.