Characteristics of Productive Thermotolerant Acetic Acid Bacteria; Acetobacter sp. A10

Aims: Adaptation of native bacterial strains in every climate is considerable. Evaluation of native thermotolerant acetic acid bacteria effectively influence their optimal and beneficial use. The aim of this study was to evaluate the characteristics of productive thermotolerant acetic acid bacteria with focusing on Acetobacter sp. A10. In the present experimental study, the native thermotolerant strain of Acetobacter sp. A10 was used. For preparation of fresh culture and maintenance of thermotolerant strain glucose yeast extract calcium carbonate was used, which contained 50g glucose, 10g yeast extract, 30g calcium carbonate, and 25g agar per liter. In order to produce acetic acid by the strain of Acetobacter sp. A10, ethanol yeast extract broth culture was used. Effect of initial concentrations of ethanol and acetic acid on the production of acetic acid by Acetobacter sp. A10 was investigated, using a culture meda containing 2% to 9% ethanol and 2% to 9% acetic acid. Findings: This strain could produce 40g/l acetic acid from 4% (WV) ethanol in baffled shake-flasks in 24h under optimized conditions of pH 4, at 33°C, and 150rpm. The strain at 37 °C was able to produce acetic acid in the presence of a 4% and 8% initial concentration of acetic acid a. The rate of fermentation was 2.5 times more than mesophilic ones. Acetobacter sp. A10 is active in a different temperature range compared to mesophilic strains and it is able to withstand ethanol and acetic acid to more concentrations. In addition, it has higher efficiency, as well as greater rate and power of fermentation.