| With the development of economy, the energy problem and environmental issue are paid more and more attention. Ethanol has been considered as one of the substitute fuel of petrol. At present, many countries are interested in the development of fuel ethanol.In this research, the morphology, physiological characteristic, the ability of ethanol tolerance and ethanol yields of Zymomonas mobilis were studied. The result showed that the bacteria could tolerate ethanol at a concentration of 17% (v/v).The ethanol yield was obtained as 61.5 g/L when ferment in glucose(150 g/L). While the cultivating temperature was rised from 30℃to 36℃, the morphology of Z.mobilis varied from normally dividing cells to filaments. However, the changing of morphology is reversible when the temperature decreased from 36℃to 30℃.After single-factor experiment, the factors which influence the ethanol yield (e.g. carbon sources, nitrogen sources, inoculation volume, pH value, temperature) were figured out. According to the results of orthogonal experiment, the optimal fermentation conditions were achieved as: 200 g/L glucose, 7.5 g/L yeast extraction, 10 % inoculum, the initial pH value was 6.5, the temperature adjusted to 30℃. The maximal ethanol production of Z-1 was obtained as 87.06 g/L.The strain ZE-11 was isolated after mutanted by ethyl methyl sulfonate (EMS) and UV mutagenesis. Under the optimum fermentation conditions (200 g/L glucose), the ethanol yield increased by 9.26% compare to the original strain.The small scale fermentation was carried out in a 8-liter bioreactor using sugarcane juice (227 g/L total sugar) as substrate. The ethanol yield was achieved as 105.7 g/L with a cell dry weight of 3.6 g/L. The results indicated that the mutant ZE-11 is a considerable strain for sugarcane ethanol production.
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