Conditions of acetic acid producing by Brettanomyces yeast

Brettanomyces yeast has found their application in brewing (Lambic and Guezze style). Acetic acid obtained during fermentation by Brettanomyces yeast participates in the synthesis of ethers responsible for the taste and aroma component of the beverage. In this study the ability of four yeast strains Brettanomyces ( intermedius, bruxellensis, custersianus, and clausenii ) to produce acetic acid on a medium containing glucose has been determined. The strain B. bruxellensis has been found to be the most effective for the biological acidification of the medium including brewing. The optimum mode of air output at full consumption of glucose and achievement of maximal values of volumetric equal to 0.06 g/(l×h) and specific yield of acetic acid equal to 0.43 g/(g×h) has been determined, it is equal to 300 l/h. Influence of temperature and mixing of the medium on the production of acetic acid by B. bruxellensis in an environment containing glucose at the temperature of 26, 30, 34 °C and the speed of the mixer 250, 350, 450 rpm has been investigated by statistical methods. The optimal conditions for the maximum volumetric output of acetic acid - 0.114 g/(l×h) are the temperature 28 °C and the mixer speed 250 rpm.