Isolation, Identification And Characteristics Of PAHs-degrading Bacteria And Preliminary Study On Catechol 2, 3-Dioxygenase

The environment problems are more and more severe along with High-speed economic development. So, pollution remendiation is staring us in face. Polycyclic aromatic hydrocarbons are kinds of aromatic compounds, produced in many ways and difficult to clean up. The elimination of polycyclic aromatic hydrocarbons draws the attention of the public because of its threaten for human's health. microbial degradation is an important measure for polycyclic aromatic hydrocarbons remendiation. As for this reason, getting high-effective degrading bacteria of polycyclic aromatic hydrocarbons, as well as doing rearch for its degrading characteristics and genes related with degradation and bring this fruits into the practical application must be valueable.A strain that can grow on polycyclic aromatic hydrocarbons as the sole source of carbon and energy, A3, was isolated from soils nearby Jiannan Finery. And 3A is identified as Bacillus by modality observation, biochemical identification and 16S rDNA analysis. The polycyclic aromatic hydrocarbons -degradation conditions of the bacteria were analyzed. The optimal growth temperature is 37℃and the optimal growth pH value is 7.0. At this condition, the efficiency of phenanthrene degradation is 68.9% in fifteen days and pyrene degradation is 78.8% in thiry days. The reports of Bacillus degrade polycyclic aromatic hydrocarbons is rarely up to now, so study on this bacteria is valuable and meaningful.Optimal growth conditions and constitutes of culture media is made certain by monofactorial experiment and orthogonal test.The optimal condition of degradation is 37℃, pH7.0, 150rpm and 150ml culture media in 300ml shake flask. The degradation efficiency could be improved by 40% through adding 0.5% Tween80 into the culture media. Add 0.5% Tween80 into culture media could improve degradation efficiency by 40%. The pyrene degradation efficiency is increased in certain extent when synergistic degradation with White Rot Fungi. The whole ORF of catechol 2, 3-dioxygenase is gain by chromosome walking. The data are blasted on NCBI. The result is that there is rarely catechol 2, 3-dioxygenase gene of Bacillus. is reported in data-base. The blast results of other sequences show that the similarity of sequence in database is no more than 15%, and the similarity of 3A sequence with others is lower too. And, the assured result would be gotten after expression.