Comparative Genomic Analyses And Hydrocarbon Degradative Capacity On Key Degrading Genes Of The Crude Oil Degrading Marine Acinetobacter Strain

Marine petroleum pollution has a bad influence on the marine ecological environment.The traditional physical and chemical treatment methods have the hidden dangers of incomplete or side effects.The biological means can decompose the oil from the polluted sea by putting the microorganism that can be the source of the petroleum hydrocarbon to the polluted sea,and can degrade the oil quickly and do not produce the oil.The two generation of pollution is an ideal way to deal with this problem.Therefore,the research of petroleum degrading bacteria is spreading all over the world.Acinetobacter sp.Tust-DM21(GeneBank KX390866)is a highly efficient oil degrading bacteria isolated from the water and oil mixture collected from the waste oil collection area of the marine oil exploration ship of Bohai Bay.It has been found that it has a strong degradation effect on shoReal-time,medium and long chain alkanes,so the whole gene sequencing was carried out.Based on its genomic data,the number and distribution of the essential genes of Acinetobacter sp.Tust-DM21 strain were predicted.At the same time,we found that the genome contains the common shoReal-time chain alkane degradation gene AlkB and the long chain alkane degradation gene AlmA.Therefore,5 strains of Acinetobacter with the same two genes were selected for comparative genome research,including phylogenetic and co linear analysis,and their ORF,gene Island,and pre phage.CRISPR,promoter and transcription factor binding sites were analyzed and compared.In order to clarify the most suitable degradation temperature and pH condition of Tust-DM21,144h was cultured at different temperatures and pH.The variation of each component of petroleum hydrocarbon was determined by GC-MS internal standard method,and the degradation rate was calculated,and the best degradation condition of Tust-DM21 was clarified.By measuring the degradation rate,By determining the degradation rate,the degradation rate of medium alkanes was 97.5%after 144H,98.5%for long chain alkanes,81%for the naphtha,87%for aromatic hydrocarbons,and excellent degradation ability for each component of petroleum.In order to understand the expression of AlkB and AlmA in the degradation process more deeply,the degradation time of the bacteria in the 7 growth periods above is analyzed by Real time-PCR,and the expression trend of the two bases in 144h is studied.Conclusion:the essential genes for Acinetobacter sp.Tust-DM21 are mainly concentrated in carbohydrate metabolism,energy metabolism,translation and amino acid synthesis,and GO functional classification indicates that these functional genes are associated with petroleum degradation,and the genome contains 2754 ORF,2 intact pre phages and 3 incomplete pre phages and 10 genes.The island,3 CRISPRs,of which two gene islands were related to the prephage,and the Real time-PCR experiment of the Real time-PCR and the AlmA gene showed that the expression of the two degrading genes were all high to low high,and the growth rate was also slow to fast.The best degradation condition of Acinetobacter sp.Tust-DM21 is in 35? and pH8.5.