Isolation And Biodegradation Characteristics Of Bifenthrin Degrade Strains

Bifenthrin is one of the most widely used synthetic pyrethriod insecticide. The contamination to the environment has aroused most of the public concern. Microorganisms play an important role in the treatment of remained pesticide.It’s an research hotspot in recent years because of its low cost, high efficiency, no secondary pollution, and ecological restorative. This paper has developed a method for bifenthrin determination by micellar electrokinetic capillary chromatography.An highly-effective-Bifenthrin-degradation-strain has been isolated. Its degradation characters and its application in soil have been investigated.A method for the determination of bifenthrin has been established by micellar electrokinetic capillary chromatography, and was applied to detect bifenthrin in soil. The optimum conditions was:UV detection at210nm, a buffer of70mmol/L boric acid, containing20mmol/Lβ-CD and70mmol/L SDS, pH8.0, separation voltage at25kV. The quantitative linear ranges were15.625-500mg/L and with correlation of 0.9966. The limits of detection were0.176mg/L and the values of recoveries for bifenthrin were arranged from97.2%-101.2%, RSD<3%.Bacteria strain that could utilize bifenthrin was isolated from manufacturing industrial soil on the basis of enrichment cultivation.It was identified as Pserdomonas sp. by the AMS-VITEK32.The degradation characters investigate indicate this strain can tolerance bifenthrin with high concentration. The growth of the strain related positively to the degradation ratio of bifenthrin. The optimum condition was:pH7, culture temperature30℃,the initial concentration of bifenthrin200mg/L, the rotate speed of table150r/min, the quantity of inoculation at10%, and additives of glucose100mg/L.The best degradation time was in72h.The degradation conditions were optimization by response surface methodology using the Design-Expert software. Results indicated that the optimum degradation condition was:quantity of inoculation at13.42%, culture temperature31.81℃, the initial concentration of bifenthrin226.94mg/L,pH7, the rotate speed of table150r/min, additives of glucose100mg/L, and the degradation time was in72h.The degradation model of bifenthrin was:C=C0e-0.0172t.This mdel was a first-order kinetics. The half-time for bifenthrin degradation was40.4h when the initial concentration of bifenthrin was200mg/L.And the speed of degradation reach the fastest at36h.The application of the strain in soil was studied. The results showed that the relationship between the bacteria amount and the degradation efficiency was positive correlation.When the bacteria amount exceed30ml, the degradation efficiency growth a little.The degradation of bifenthrin was obvious in3d. And the degradation effect was better when the concentration of bifenthrin was below30mg/kg.