一株2-氯酚优势降解菌的生物降解机理

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1、籃蜮工學陡本科毕业论文一株2■翱分OOS的生物醐专业生物工程班级B生物102学号1010307227学生姓名张蓉指导教师李朝霞完成日期2014年6月5日一株2-氯酚优势降解菌的生物降解机理摘要：取木实验室保藏的一株2-氯酚优势降解菌LF1-4至牛肉膏蛋白胨培养基上连续活化2次，用无菌去离子水洗卜*并稀释成约108cfu/mL的菌悬液。按10%接种量接种于含宥100mg/L2-氯酚为唯一碳源的无机盐培养基中进行避光发酵，分别测定培养溫度和pH两种主耍影响因素卜'的2-氯酚的降解率，从而获得较适宜的降解条件。在此适宜的条件不，定时取样，分别用气相色谱仪测定2-氯酚浓度、用气-质联

2、用仪检测底物减少和产物生成的过程以及用氯离子选择性电极法测定氯离子浓度，确定2-氯酚生物降解机制。结來表明，优势降解菌LF1-4的适宜培养温度和pll是35"C和pH8.0。气相色谱显示2-氯酚的浓度随时间有规律的减少，此结來与气-质联用仪测定的底物的减少过程一致，中间产物生成呈先增加石减少而终产物呈逐渐增加趋势。氯离子浓度不断增加，增加的速度从慢到快最盾趋于平稳，且其浓度的增加明显滞盾于2-氯酚浓度的减少，由此可推出2-氯酚的生物降解机制是先开环，盾脱氯。关键词：2-氯酚；优势降解菌；氯离子；生物降解机理Biologicaldegradationmechanismofado

3、minantdegradationstrainon2-chlorophenolAbstract：AdominantdegradationbacteriastrainLF1-4on2-chlorophenolpreservedinourlabwastwicelyactivatedonthebeefextractpeptonemediumanddilutedtoapproximately108cfu/mLofbacteriasuspensionwiththesteriledeionizedwater.Withinoculationamount10%，thebacteriasusp

4、ensionwasdarkfermentatedinthemineralmedium(MM)with100mg/L2-chlorophenolasexclusivecarbohydrate.Thedegradationrateof2-chlorophenolundertwomainfactorsontheculturetemperatureandpHweremeasuredtoobtainmoreappropriatedegradationconditions.Undertheappropriateconditions，withtimingsampling，thebiodeg

5、radationmechanismson2-chlorophenolwasanalyedwith2-chlorophenolconcentrationsdeterminedbygaschromatography(GC)，reducionofthesubstrateandgenerationoftheproductdeterminedbygaschromatography-massspectrometer(GC-MS)，andchlorideionconcentrationdeterminedbychlorineionselectiveelectrode.Theresultss

6、howthatsuitableculturetemperatureandpHoftheadvantagedegradingstrainLF1-4were35°CandpH8.0.Theconcentrationof2-chlorophenolreducedregularlyovertimedeterminatedbyGC，whichisconsistentedwiththereductionprocessofthesubstratedeterminatedbyGC-MS.Intermediateproductwasfirstincreasedandthendecreasedw

7、hilethefinalproductwasgraduallyincreasing.Theconsistentlyincreasingspeedofthechlorideionconcentrationwasfromslowtofastandfinallystabilized.Theincreasingofchlorideionconcentrationlaggedbehindthereducingofthe2-chlorophenolconcentration.Therefore,itwaslaunc