强化固定化Methylibium petroleiphilum PM1细胞降解MTBE及动力学特性分析  

Biodegradation of Methyl tert-Butyl Ether by Stabilized Immobilized Methylibium petroleiphilum PM1 Cells and Its Biodegradation Kinetics Analysis

作　　者：成卓韦[1] 傅凌霄[1] 蒋轶锋[1] 陈建孟[1] 张荣 

机构地区：[1]浙江工业大学生物与环境工程学院,杭州310032 [2]浙江天蓝环保技术有限公司,杭州311202

出　　处：《环境科学》2011年第5期1511-1517,共7页Environmental Science

基　　金：国家科技支撑计划项目(2007BAE58B07);浙江省重点创新团队项目(R5090230)

摘　　要：采用海藻酸钙包埋固定化高效降解菌Methylobium petroleiphilum PM1降解水相中的甲基叔丁基醚(MTBE),考察了不同强化方法对凝胶颗粒机械强度和降解活性的影响.响应面结果表明,交联剂和培养基中Ca2+浓度分别为0.2 mol·L-1和1.38mmol·L-1,化学交联剂聚乙烯亚胺(PEI)浓度为0.1%时,强化固定化细胞具有较高的降解活性.在此条件下,凝胶颗粒在24h内机械破碎率仅为5.98%,并能连续使用400 h以上,未出现颗粒溶解破碎现象,降解速率较为稳定.扫描电镜观察,PEI处理后的凝胶颗粒表面形成一层薄膜,能有效防止细胞泄漏,并能维持PM1细胞良好的生长繁殖.动力学分析表明,降解的限速步骤为生化反应,直径3 mm凝胶颗粒对底物的扩散限制最弱;而高浓度的PEI能引起严重的扩散限制现象.Methylibium petroleiphilum PM1,which is capable of degrading methyl tert-butyl ether（MTBE）,was immobilized in calcium alginate gel beads.Several methods were explored to increase the strength of these gel beads.The central composite design analysis indicated that the introduction of 0.2 mol·L-1 Ca2 ＋ into the crosslinking solution,1.38 mmol·L-1 Ca2 ＋ into the growth medium and 0.1% polyethyleneimine（PEI） as the chemical crosslinking agent could increase the stability of the Ca-alginate gel beads with no loss of biodegradation activity.The stabilized immobilized cells could be used 400 h continuously with no breakage and no bioactivity loss.Examination of scanning electron microscope demonstrated that a membrane surrounding the gel beads was formed and the cells could grow and breed well in the stabilized calcium alginate gel beads.Kinetic analysis of the gel bead-degradation indicated that the rate-limiting step was biochemical process instead of intraparticle diffusion process.The diameter of 3 mm affected the biodegradability less while high concentration of PEI induced much more serious mass transfer restraint.

关 键 词：MTBE 强化固定化细胞 响应面 使用批次 降解动力学 

分 类 号：X703.1[环境科学与工程—环境工程]