Effect of physical parameters on alcohol dehydrogenase and aldehyde dehydrogenase during the production of acetic acid from ethanol by an ethanol resistant strain Saccharomyces cerevisiae AB100

Department of Chemical Engineering, Biochemical Division, University of Calcutta, 92, Acharya Prafulla Chandra Road, Kolkata-700 009, India E-mail : modhurima_chakraborty@yahoo.co.in Manuscript received 15 December 2008, accepted 5 February 2009 An ethanol resistant strain of Saccharomyces cerevisiae AB100 was examined to ascertain Its acetic acid production. The influence or physical parameters on acetic acid production and activities of alcohol dehydrogenase (alcohol : NAD+ oxidoreductase; E.C. 1.1.1.1) and aldehyde dehydrogenase (aldehyde : NAD+ (P+) oxidoreductase; E.C. 1.2.1.5) were also observed. The optimal conditions finally found were : initial pH = 4.5, Incubation temperature = 30 °C, incubation time = 48 h, volume of medium = 85 ml, age of inoculum = 48 h and cell density = 10.25 x 105. These optimal conditions were also optimum for the activities of the two main regulatory enzymes i.e. alcohol dehydrogenase and aldehyde dehydrogenase