IMPROVEMENT OF THE LONG-TERM SURVIVAL OF ACETOBACTERIUM-WOODII BY LIMITING ACETATE PRODUCTION

The viable count in fructose-grown cultures of Acetobacterium woodii fell to undetectable levels 186 h after the stationary phase was reached. The loss of viability was due to accumulation of undissociated acetic acid, since loss of viability could be induced artificially in cultures grown at pH 6.8 by adjusting the pH to 5.0 or by adding high concentrations of acetate. Survival was greatly improved when cultures were grown at low initial fructose concentrations (less than or equal to 2 g/l) to limit acetate production, since viable cells could still be detected after 73d.