[以Fe(Ⅲ)为电子受体的聚磷菌筛选、鉴定及聚磷特性] 电子受体

　　作者简介：任丽平（1971），女，副教授，博士生，主要从事资源微生物和水污染控制研究，(Email)xhrlph@163.com。　　张智（通信作者），男，教授，博士生导师，(Email)zhangzhicq@126.com。摘要：结合平板分离法、poly-P和PHB染色以及柠檬酸铁还原实验，从污水处理厂活性污泥中分离获得一株以Fe(Ⅲ)为电子受体厌氧聚磷的聚磷菌株AP3, 其16S rDNA与Pseudomonas mosselii ATCCBAA-99的同源性为99%。菌株AP3于柠檬酸铁液体培养基和无铁液体培养基中厌氧避光、27 ℃静置培养，在含有Fe(Ⅲ)的培养基中比在无Fe(Ⅲ)的培养基中生长好；菌株AP3在无Fe(Ⅲ)的培养基中，表现出典型的厌氧释磷特征，释磷量为3.68 mg·L-1；在含有Fe(Ⅲ)的培养基中，先厌氧释磷，释磷量为6.62 mg·L-1， 10 h之后开始厌氧聚磷，聚磷量为5.89 mg·L-1。菌株AP3能以Fe(Ⅲ)为电子受体，具有厌氧聚磷特征。
　　关键词：聚磷菌；筛选；鉴定；氧化铁；电子受体
　　中图分类号：X172文献标志码：A文章编号：16744764（2012）03014605
　　Screening and Identification of Phosphate Accumulating Bacteria
　　with Fe (Ⅲ) as Electronic Acceptor and its Effects on
　　PhosphorusAccumulating Characteristics
　　REN Liping1，2，ZHANG Zhi1，TANG Yun2
　　（1. College of Urban Construction and Environmental Engineering, Chongqing University, Chongqing 400045, P. R. China；
　　2. College of Biological Sciences, China West Normal University, Nanchong 637002, P. R. China）
　　Abstract:A phosphorus accumulation organism strain AP3 with Fe (Ⅲ) as electronic acceptor was screened from activated sludge through such processes as dilutionplate method, polyP, PHB staining and ferric citrate reduction. Its 16S rDNA is identical to that of Pseudomonas mosseliisp ATCCBAA99 at 99% level. By comparing the AP3 being cultured in ferric citrate fluid medium and the one in nonferric fluid medium at 27 ℃, it was found that ferric citrate fluid medium was beneficial for the AP3. AP3 cultured in nonferric fluid medium showed significant anaerobic and phosphorus releasing characteristic, the phosphorus releasing amount of which was 3.68 mg·L-1. AP3 cultured in ferric fluid medium was also characterized by anaerobic and phosphorus releasing property at the first stage, the phosphorus releasing amount of which was 662 mg·L-1，which was higher than the former; And at the second stage which started from the 10h, it was characterized by anaerobic and phosphorus accumulating property, the phosphorus accumulating amount of which was 5.89 mg·L-1. Fe (Ⅲ) is the electron acceptor of AP3 which shows typical anaerobic and phosphorus absorbing property.
　　Key words:phosphorus accumulation organism；screening；identification；iron oxides；electronic acceptor 现代污水生物强化除磷法是通过聚磷菌超量摄取废水中的磷，以聚磷酸盐的形式积累于细胞内，然后作为剩余污泥排出，从而实现磷的去除。在该过程中聚磷菌起着关键的作用, 目前研究表明假单胞菌属(Pseudomonas)是生物除磷的重要功能菌，是厌氧/好氧条件下的主要菌种之一［1］,并在试验过程中一直保持着较为稳定的优势地位［2］。目前，仅发现其超量吸磷反应的电子受体有2类，一类是以O2为电子受体，在好氧条件下完成吸磷，另一类是以NO3-、NO2-为电子受体，在缺氧条件下完成吸磷，前者称为好氧聚磷菌(APB)，后者称为反硝化聚磷菌(DPB) ［3］。同时，该过程受到溶氧、有机物、pH值［4］、厌氧时间［5］、金属离子［6］以及NO3-、NO2-浓度［7］等因素的影响。目前，生物除磷仍处于发展阶段，生物除磷效果不稳定，大多数学者集中于除磷工艺的改进，而相关的机理研究还不够成熟。对聚磷机理研究的最大障碍是高活性聚磷菌的获得，至今分离、鉴定的聚磷菌仍然是极少数［8］，新的分离方法仍在不断探索中［9］。而人们利用分子工具对污水反应器的调查结果表明污水微生物具有多样性，许多未培养微生物被发现在脱磷中扮演着重要角色［10］。 〖=D(〗任丽平，等：以Fe(Ⅲ)为电子受体的聚磷菌筛选、鉴定及聚磷特性〖=〗