Zahra Osanloo - department of Biotechnology, School of Engineering, Imam khomeini International University, Qazvin, Iran
Ramin Hosseyni - department of Biotechnology, School of Engineering, Imam khomeini International University, Qazvin, Iran

Zymomonasmobilis is undoubtedly one of the most uniqe bacterium within the microbial world. Its ability to energy production in favor of product formation, to physical and chemical environment manipulation, as well as its restricted product formation, makes it an ideal microorganism for microbial procees development.The bacterium Zymomonas mobilis is one of the best ethanol producers (Wang et al 2012).this bacterium ferments sugars to produce ethanol with two biochemically distinct isoenzymes of alcohol dehydrogenase (adh1 and adh2). alcohol dehydrogenase is a key enzyme in ethanol production by the Entner-Doudorrof (ED) pathway.The adh1 and adh2 isoenzym are quaite distinct with respect to substrate ranges (Keshave et al, 1990) .In Zymomonas mobilis adh2 is the dominate enzyme during fermentation, although both isoensymes are essential for the production of ethanol.