Influence of fermentation temperature on semi-continuous acetification forwine vinegar production

This paper describes semi-continuous acetic acid fermentations for wine vin egar production performed isothermally and using temperature gradients in o rder to determine the influence of temperature on this industrial biotransf ormation. Acetifications were conduced in 6- to 100-1 reactors. Overall pro cess productivity improved about 15-20% using a temperature gradient. An in itial temperature of 32 degreesC was employed until the product concentrati on reached 90-95 g/l/h. Thereafter, the temperature was gradually reduced t o 30 degreesC until the end of the production cycle. Under these operating conditions. the 100-1 acetator yielded an overall productivity of 1.84 +/-0 .03 g/l/h, a maximum acetification rate of 2.10 +/-0.02 g/l/h. a 94.3 +/-0. 4% process yield, and a final acetic acid concentration of 116.0 +/-0.9 g/l .