Comparison Of Degrading Characters Of Oxytetracycline Degrading Bacteria And Soil Environmental Simulation Test

The high performance liquid chromatography (HPLC) method of detecting Oxytetracycline (OTC) in the media and soil was founded in the essay.Mcllvaine buffer was used for extracting the Oxytetracycline from the media and soil,Acetonitrile: KH2PO4 (0.05mol/L) (18:82,V/V) was the mobile phase which was used on the HPLC analysis.A ODS-2 HYPERSIL(250mm×4.6mm,5μm),and ultraviolet detecter (355nm) was used,column temperature was 30℃,flow rate was 1.0mL/min.The recovery of Oxytetracycline in the media and soil exceed 85% and 80%,respectively.The coefficients of variation of OTC was less than 10%,The limit of detectability(LOD) and quantitation(LOQ) of OTC were 0.01mg/L and 0.1mg/L, respectively.A screening model,which was used for picking out highly efficacy degradation bacteria of OTC,was built in the poverty media.By using initial screening,bacteria were isolated,then depurated and domesticated,two bacteria were founded finally.By using Gram staining and 16S rDNA identification of molecular biology,the bacteria were identified to be Bacillus prodigiosus and Aerobacter cloacae,respectively.Three bacteria,Bacillus prodigiosus,Aerobacter cloacae and Bacillus cereus, were named 1#,2#and3#.The bacteria were studied relatively for effect on degradation of OTC under the same condition from pH,temperature,ventilatory capacity, concentration of substrate,bacterial load,and so on,and all these factors'effect on their germ yield.As a result,1# bacterium showed OTC degradation ability doughtily under the conditions of pH8,35℃,100mL ventilatory capacity,0.1% bacterial load,150mg/L concentration of substrate,0.2% starch,1% yeast,Fe³⁺ and Zn²⁺;2# bacterium showed OTC degradation ability doughtily under the conditions of pH9,30℃,60mL ventilatory capacity,5% bacterial load,100mg/L concentration of substrate,0.2% starch,1% beef extract,Fe³⁺ and Zn²⁺;3# bacterium showed OTC degradation ability doughtily under the conditions of pH7,35℃,80mL ventilatory capacity,0.1% bacterial load,50mg/L concentration of substrate,0.2% starch,1% yeast,Fe³⁺ and Zn²⁺.The soil environment simulation test of the three bacteria were done in the lab.The soil in this test was treated by sterilizing and non-sterilizing,and 60 days of continuous culture with concentration of 10mg/kg,25mg/kg and 50mg/kg,under 6500 Lux,12h light and 12h dark in intellective luminary incubator at 25℃.The results showed that the optimum degradation time was between 20d and 40d.Besides,the degredation effect of the three bacteria to Doxycycline,which is another TCs medicine,was studied.The result of test indicated that the bacteria didn't have degrading ability to Doxycycline.