Co-culture of a Cellulose-Producing Acetic Acid Bacterium and a Beer Yeast

摘要

The bacterium Gluconacetobacter hansenii NOK21 was identified as a cellulose pellicle-forming bacterium from rancid wine. The bacterium did not show growth when glucose concentration or ethanol concentration was equal to or greater than 20% or 8%, respectively. Production of the cellulose pellicle was greatest with a concentration of cellulose polymer of 5 g/l in glucose medium. The NOK21 oxidized ethanol to acetic acid like other acetic acid bacteria and did not appear to convert glucose to acetic acid. The maximum titratable acidity of 4.13% was obtained from 5% ethanol-containing medium. Under static co-culture conditions of the acetic acid bacterium and Saccharomyces cerevisiae, the beer yeast grew under the pellicle at the bottom of the culture vessel through anaerobic metabolism whereas the bacteria grew to form a pellicle on the surface of the culture medium through aerobic metabolism. The bacterial strain NOK21 grew and synthesized cellulose polymer and produced acetic acid using glucose as a substrate in the presence of the beer yeast. Our findings about the behavior in co-culture of the alcoholic fermentation yeast and the acetic acid bacterium provide information helpful for the manufacture and improvement of fermented food products that are sour and alcoholic.