Effect Of Carbon Source On The Properties Of Rhamnolipid In Strain NY3 And The Application Of Rhamnolipid On Remediation Of Petroleum Contaminated Soil

Rhamnolipid is a biosurfactant,with many functions of chemical surfactants.In practice,it can be demulsified,flooded,and can improve the bio-availability of recalcitrant organic.Because of it's safe and non-toxic,it is not easy to cause secondary pollution to the environment.In recent years,the application of rhamno lipid has been a hot issue.Fermented carbon source types of rhamnolipid are more.In the previous study,more attention was paid to rhamnolipid production.And the reports that carbon source have an impact on the production of rhamnolipid composition,structure,performance are rare.Based on these situations,in this paper,the research work would be done.It is of great significance for directional control of fermentation rhamnolipid production.In this paper,Pseudomonas aeruginosa NY3,isolated from laboratory,was used as the tested strain,studying the effects of fermented carbon source on the composition,structure and properties of Rha compounds.To improve the yield of rhamnolipid.exploring the method of carbon source alkaline hydrolysis.Getting the following results:(1)The carbon source of fermentation can affect the yield,structure,composition and properties of rhamnolipid that produced by NY3 Strain.Grease class as carbon source,the rhamnolipid production is higher.When rapeseed oil as carbon source,the amount of rhamnolipid is the largest.The dirhamnolipids proportion in rhamnolipid can reach 70.51% when olive oil as carbon source.When oleic acid and linoleic acid were used as carbon sources,the content of monorhamnolipids was 82.74% and 87.25%,respectively.The dirhamnolipids in rhamnolipid contain short-chain esters of glycolipids of 5-8 carbon atoms when oleic acid as carbon source.The dirhamnolipids in rhamnolipid contain glycolipids of 8-12 carbon atoms,the chain is longer,when linoleic acid is being carbon source.In contrast,the ratio of monorhamnolipids in the rhamnolipid compounds,hexadecanoic acid as a carbon source,is about 80%.The ester chain can be up to 10-16 carbon.When the proportion of monorhamnolipids is higher,the emulsifying performance is better,the emulsion is stable and the CMC is low.(2)The alkaline hydrolyzing of grease will improve production of rhamnolipid.The olive oil,Waste oil and rapeseed oil were alkaline hydrolyzed 12 h,6h and 24 h,respectively,rhamnolipid production can reach the maximum.Compared with the untreated carbon source,the maximum yield of rhamnolipid can be increased by 88.2%,111.5% and 45.2% respectively.But the hydrolytic carbon source did not significantly alter the rhamnolipine component species of the rhamnolipid,only to change the ratio between the components.(3)When the hydrocarbon is treated with solid bactericide,liquid of Strain NY3 and liquid of Strain FF,rhamnolipid has a role in promoting the degradation of petroleum hydrocarbons.Under the condition of outdoor natural experiment,The effect of rhamnolipid on the degradation of C11 ~ C28 alkanes from three kinds of bacteria was the most significant.And in the three degradation systems,the eight kinds of polycyclic aromatic hydrocarbons of soil contains can be degraded to varying degrees.The average removal rates of the eight PAHs in the three degradation systems were 41.7%,45.8% and 38.0%,respectively.Under the conditions of treatment of petrochemical enterprises oily sludge in laboratory,comparing with the rhamnolipid which monorhamnolipids is main,the rhamnolipid with high dirhamnolipids has a stronger effect on the degradation of petroleum hydrocarbons in oil sludge by NY3 Strain.