一株沿海滩涂细菌的降油及生长特性研究

摘要

The bacteria that have capability to degrade crude oil were isolated from the coastal beach polluted by crude oil with the basal medium crude oil as only carbon source. The original degradation rate of diesel oil by the i-solated strains was determined. In addition, the degradation rate of diesel oil by the isolated strain was determined with the basal medium diesel oil including different concentration of glucose (0, 1,2,4,8, 16 g/L) , the different concentrations of yeast extract, peptone, carbamide, (NH4)2SO4( according to the content of nitrogen; 0. 5, 1,2 g/L) and NaH2P04(0, 4, 8 , 16 g/L) . The isolated strain was identified and growth characteristics were studied. The results showed: 5 strains bacteria grew on the basal medium crude oil as only carbon source. One of these stains had a maximum original degradation rate (19.0% ) and was numbered as Y-3. The degradation rate of Y-3 increased and reached to 79. 9% in the diesel oil medium supplemented with glucose (4 g/L). The degradation rate was increased in Y-3 in addition of yeast extract and peptone also, but not notable in added urea, (NH4)2S04 and NaH2PO4. The Y-3 was identified as Pseudomonas putida according to the result of the morphology, physiological characteristics and 16S rDNA sequence analysis. The Y-3 had fitting growth at temperature of 30 ℃ , pH 8, and NaCl concentration of 0-30 g/L.%采用以原油为唯一碳源的基础培养基,从原油污染的沿海滩涂土壤中分离筛选具有降油性能的细菌；采用柴油培养基测定分离菌株对柴油的原始降解率；通过在柴油培养基中添加不同浓度的葡萄糖(0、1、2、4、8、16 g/L),及不同浓度的酵母膏、蛋白胨、尿素、硫酸铵(以氮计,浓度为0.5、1、2 g/L)和磷酸二氢钠(0、4、8、12 g/L)后,测定分离菌株的降油性能；鉴定分离菌株并研究其生长特性.结果表明:共分离到5株能以原油为唯一碳源生长的细菌,其中1株原始降油率最高(19.0％),编号为Y-3;在添加1 g/L以上葡萄糖时,Y-3菌株降油率升高,添加4 g/L葡萄糖时达最高(79.9％)；酵母膏和蛋白胨可提高Y-3菌株的降油率,尿素、硫酸铵和磷酸盐对降油率影响不明显；根据形态学、生理生化鉴定以及16S rDNA序列分析,确定Y-3菌株为恶臭假单胞菌Pseudomonas putida,Y-3菌株的最适生长温度为30℃,最适生长pH为8,适宜生长NaCl浓度为0～30 g/L.