Diversity Analysis Of Bacteria And Alkane Periplasmic Transport Mechanism Of Alcanivorax Dieselolei B5

At present,with the deterioration of marine oil pollution,the degradation mechanism of marine petroleum hydrocarbons has acquired more and more attention from people.A detailed study on the regulation mechanism of alkane metabolism in the Alcanivorax dieselolei B5 was conducted in our laboratory.We have obtained its alkane outer membrane transport system,which was experimentally verified to be three different OmpT proteins,transporting different chain length alkanes,respectively.However,the study of its inner-membrane alkane transport system has not yet been carried out.In all studies reported in the current,no inner-membrane transport system has been found having the capacity to transport alkane yet.In this paper,a group of TRAP systems was found through comparison analysis of A.dieselolei B5 genome notes,with numbers B5T₀3318（Dct P）,B5T₀3317（Dct Q）and B5T₀3316（Dct M）.In this study,substrate binding protein Dct P was expressed abundantly in Escherichia coli and purification thoroughly.Its three-dimensional structure was analyzed and it was found to have a similar structure with the reported substrate binding proteins of the classical TRAP system.Then we found it really has a very good affinity with C12 and C16 through SPR technology.From above,we can conclud that this system must play a key role in the alkane transport of A.dieselolei B5.Surface sediments were collected at the India ocean station（49.54?E,37.88?S）on December 21,2014,which was executed by” Ocean number one” on voyage thirty-fourth.A batch of strains was enriched by the way of using petroleum hydrocarbon as the sole carbon source.A new strain MT13131 of Alcanivorax.spp,which can degrade petroleum hydrocarbons,was isolated.After the comparison of 16 Sr DNA sequences,it was found that MT13131 has the highest similarity（96.93%）with Alcanivorax marinus R8-12T（KC415169）.MT13131 can grow on M2 B medium,standard phenotypic tests showed that the strain was a Gram-stain-negative and aerobic,approximately 0.5-1.5 μm long and 0.3-0.6 μm wide.The single colonies of MT13131 on nutrient agar were milk white and wet.It formed smooth surface and regular edge.The diameter of the colonies is about 0.2mm.Cells can grow under the temperature from 10℃ to 42℃ weekly,but the optimum growth temperature is 28℃.The conditions for growth are pH 3-10 and NaCl 1–12%（w/v）.The optimum pH for growth is pH 6-8,and the optimum concentration of NaCl is 3–4%（w/v）.Physiological and biochemical comparisons were made with the type species,it was found to have the basic characteristics of the Alcanivorax.spp,and it is also characteristic of being different from other Alcanivorax.spp.Therefore,MT13131 could be regarded as a new strain of Alcanivorax.spp,which was named Alcanivorax movere,and the type species is MT13131.MT13131 has a wide range of alkane degradation（C8-C32）.Due to its wide range of alkane degradation,it must have multiple sets of alkane degradation metabolic network.A small number of functional genes associated with alkane degradation have been identified in their genomes,and the research of functional gene needs further study in the future.These results have far-reaching implications for deep understanding of the mechanism of degradation of alkanes,and even better development and utilization of resource value of microorganisms.