假单胞菌pha降解苯酚的相关研究论文.docVIP

　 摘　　　要　  苯酚是工业排放废水中主要的有害污染物之一  利用微生物修复含高浓度苯酚  的土壤和水体是一种经济有效且无第二次污染的方法 近几十年的研究表明，许多微  生物包括假单胞菌  Ｐｓｅｕｄｏｎｏｍｏｎａｓ．ｓｐ  均参与了此类有机毒物的生物降解反应  本研究从假单胞菌 Ｐｓｅｕｄｏｎｏｍｏｎａｓ．ｓｐ 中筛选并得到了一新菌株 Ｐｈａ 经过鉴定证  明该菌株能以苯酚为唯一碳源生长  并通过诱导筛选使其苯酚选择压力从 ４００ｍｇ／Ｌ  逐步提高到了 ７００ｍｇ／Ｌ 对羟化酶基因保守序列的 ＰＣＲ 检测 发现没有扩增到特异的  保守条带  推定其降解苯酚的生物途径可能不是羟化途径  而是羧化途径  测量其  降解苯酚的曲线  以此项研究为基础讨论了苯酚污水处理工艺设计的原则  进一步  用最小二乘法线性回归  发现 Ｐｈａ 菌株降解苯酚的生物降解过程后部符合一级反应  动力学方程  在应用十二烷基磺酸钠  ＳＤＳ  作为增溶剂时  发现在 ＳＤＳ 浓度为 ５０  １５０ｍｇ／Ｌ 时 降解苯酚的速率随 ＳＤＳ 浓度增加而提高 ＳＤＳ 在低浓度时对菌株生长 影响很小 但浓度达到 ３００ｍｇ／Ｌ 时，对其生长开始有了明显的抑制作用 由此得出 ＳＤＳ  的理论最佳投放浓度为 １５０ｍｇ／Ｌ 　  　  关键词 　  　假单胞菌　 ＳＤＳ　 苯酚　生物降解　 Ｉ 　 Ａｂｓｔｒａｃｔ　  A new  strain ,named Pha, was domesticated from Pseudonomonas.sp Strain  AB93188 by phenol selection. In order to obtain the expected strain the pressure applied for this selection is the high concentration of phenol with the ranges between 400mg/L and 700mg/L and selected bacterial strain has been proved to grow on the medium with phenol as sole carbon source.The degradation curve based on experimental data showed that there is an inflexion in it. The possible reasons for the curve inflexion and correspond principle of phenol waste water treatment techniques have been discussed. In the meantime, the kinetic analysis for biodegradation has been programmed and the results showed that the procedure accord with the first order kinetic model.To speed up the phenol degradation, SDS was added in the treatment phenol solution and the observation indicated that the addition of SDS fit the expectation of the experimental design. However when the concentration of added SDS up to 300mg/L,the phenol degradation velocity was decreased.PCR analysing the genomic DNA isolated from the Pha strain no special band of conservative sequence related to hydroxnase was founded.which indicated that the possible path of phenol degradation may be carboxy path-way. Key words: SDS; phenol ; biodegradation; linear regress  　  ＩＩ 独创性声明 本人声明所呈交的学位论文是我个人在导师指导下进行的研究工作及取得的研