Effects Of Extracellular Actives On The Process Of Petroleum Hydrocarbon Biodegradation By Pseudomonas Aeruginosa

Pseudomonas aeruginosa could produce abundant extracellular actives, such aspyocyanine, rhamnolipid and protease, and it degrades petroleum hydrocarbons. So ithas potential application value in treating the petroleum hydrocarbons. At present, it isnot very clear the extracellular actives about secreted Pseudomonas aeruginosarelationship with it degrades hydrocarbons. Its application in repair to environmentalpollution has a realistic significance.In this paper, using the research methods, like gas chromatography, redoxworkstation, infrared, ultraviolet and so on, in a variety of petroleum hydrocarbonsconduct carbon source. Studying on the effect and mechanism of extracellular activesabout pyocyanin and rhamnolipid on degrades of hydrocarbon. For the followingresearch.(1) Pseudomonas aeruginosa NY3could secrete rhamnolipid. Compared with therhamnolipid-free conditions, rhamnolipid could obviously promote to degrade largermolecular weight alkanes like C26-C33of Pseudomonas aeruginosa NY3, and thedegradation rates of the alkanes ranging from hexacosane to tritriacontane in the crudeoil were promoted to about60%by the rhamnolipid. Its degradation mechanism hasmainly to alter the surface properties of bacteria and the bacteria intake process ofhydrophobic compounds. Rhamnolipid less than100mg/L, with the concentrationincreased, the surface hydrophobicity of the bacteria increased slightly. Reaction on20min and90min, cells harvested from LB medium accumulated were intake0.63nmol/mg dry cell and1.10nmol/mg dry cell more hexadecane with the assistance of100mg/L rhamnolipid. This results indicated that rhamnolipid could accelerate masstransfer rate of hydrophobic organic compounds onto cells. The analysis of FT-IRsuggested that the ratio of the hydrophilic functional groups containing in cellsharvested from both of the above medium reduced obviously after interaction withrhamnolipid.(2) Pseudomonas aeruginosa NY3could secrete pyocyanine, too. The Studydetermines the redox potential of pyocyanin about-0.264V. Increasing NY3bacteriaproduced by pyocyanine, bacteria cell growth rate also has accelerate significantly.From the above, pyocyanine could promote to degrade of hydrocarbons. The reason ofpyocyanine promoting Pseudomonas aeruginosa NY3to degrade petroleumhydrocarbons is to improve hydrocarbon oxidase actives.