| The culture of alcohol has a long history about several thousand years, and the application of ethanol in daily life has expanded into many areas. But, drinking much alcohol could threaten people's health, and the emission of ethanol waste liquor without control could destroy the balance of ecosystem, bring bad influence to the surroundings. Ethanol detoxification drug and the treatment of ethanol waste liquor become the key points in society, because of the increment of people's life quality requirement, and care of environment protection. The main contents of this research were as following:1 Screened ethanol detoxification bacteria based a method of transparent circleWe obtained four strains with potentiality in ethanol detoxification from different materials, such as vinasse which has become rancid, rotten fruits and pickled vegetables. We numbered as No.Ⅰ, No.Ⅳ, No.Ⅶ, and No.Ⅷ, and all the strains were Gram negative bacteria.2 Identification and analysis of bacterial strains with potentiality in ethanol detoxification based on 16S rDNA sequence16S rDNA sequences of the four obtained strains were got using 3730 DNA Analyzer. The results showed that, the number of 16S rDNA sequences of No. I strain was 1413, after the analysis of homeology and phylogenetic tree, No. I strain had 100% homeology with Lactobacillus plantarum; and the number of 16S rDNA sequences of No.Ⅳstrain was 1233, it had 99.1% homeology with Lactobacillus hilgardii; and the number of 16S rDNA sequences of No.VII strain was 1354, with 100% homeology with Acetobacter pasteurianus; the last was No.Ⅷstain, it had 1354 base pairs, and had 99.5% homeology with Lactobacillus hilgardii. 3 Modify the medium culture of ethanol detoxification bacterial strains using intersection methodWe found the No.Ⅶhad the higher ability of ethanol detoxification than other three after experiments. The cultural medium was studied in this research, the optimum carbon source was beef extract, and the optimum nitrogen source was peptone. We modified the cultural medium using intersection method, and the results showed that, the optimum medium was the combination of 0.5% beef extract,1.0% peptone,0.3% NaCl,8% absolute ethyl alcohol (V/V),0.1% K2HPO4-3H2O,0.05% MgSO4-7H2O, and 0.001% FeSO4·7H2O. When the strain was cultured in the modified medium, the ability of ethanol detoxification was 3.19 times as before.4 Study the influence of environmental factors to the growth of ethanol detoxification bacteriaWe studied the influence of environmental factors to the growth of ethanol detoxification bacteria, such as temperature, pH value and rotating speed. The results showed that, the optimum cultural temperature was 35℃, and the initial pH value was 5.5. There was no significant influence to the growth when it was cultured in 60 r/min, 120 r/min and 180 r/min, however, the growth rate was very low in 0 r/min. So from the results, the optimum environmental factor was the combination of the temperature 35℃, initial pH value 5.5 and 60 r/min.5 Study the influence of organic acid to the growth of ethanol detoxification bacteriaWe studied the influence of different organic acids to the growth of ethanol detoxification bacteria, malic acid, acetic acid and citric acid, and the gradients were 0.3%,0.5% and 0.7%. The results showed that,0.5% malic acid could promote the growth of bacteria, however,0.7% inhibited the growth of the strain. All the gradient of acetic acid inhibited the growth of the strain; 0.3% citric acid could promote the growth of the strain, but, both 0.5% and 0.7% inhibited the growth. So the 0.5% malic acid could promote the growth of ethanol detoxification bacteria.The obtained stains could lay the background for further research and the application of industrial production, and show a new direction for new type of bio-antialcoholismic drug and the treatment of ethanol waste fluid by biological method has the sense of guidance in the practice. |
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