Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
Microb Ecol. 2010 Feb;59(2):357-68. doi: 10.1007/s00248-009-9631-8. Epub 2010 Jan 28.
Phyllosphere bacteria on ornamental plants were characterized based on their diversity and activity towards the removal of polycyclic aromatic hydrocarbons (PAHs), the major air pollutants in urban area. The amounts of PAH-degrading bacteria were about 1-10% of the total heterotrophic phyllosphere populations and consisted of diverse bacterial species such as Acinetobacter, Pseudomonas, Pseudoxanthomonas, Mycobacterium, and uncultured bacteria. Bacterial community structures analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis from each plant species showed distinct band patterns. The uniqueness of these phyllosphere bacterial communities was partly due to the variation in leaf morphology and chemical properties of ornamental plants. The PAH degradation activity of these bacteria was monitored in gas-tight systems containing sterilized or unsterilized leaves. The results indicated that phyllosphere bacteria on unsterilized leaves were able to enhance the activity of leaves for phenanthrene removal. When compared between plant species, phenanthrene removal efficiency corresponded to the size of phenanthrene-degrading bacteria. In addition, phyllosphere bacteria on Wrightia religiosa were able to reduce other PAHs such as acenaphthylene, acenaphthene, and fluorine in 60-ml glass vials and in a 14-l glass chamber. Thus, phyllosphere bacteria on ornamental plants may play an important role in natural attenuation of airborne PAHs in urban areas.
基于其多样性及其对多环芳烃（PAHs）去除的活性，对观赏植物叶际细菌进行了特征描述，PAHs 是城市地区空气中的主要污染物。能降解 PAHs 的细菌数量约占总异养叶际菌群的 1-10%，包含多种细菌，如不动杆菌属、假单胞菌属、假单胞菌属、分枝杆菌属和未培养细菌。从每种植物种类的聚合酶链反应-变性梯度凝胶电泳分析的细菌群落结构显示出不同的条带模式。这些叶际细菌群落的独特性部分归因于观赏植物叶片形态和化学成分的变化。在包含灭菌或未灭菌叶片的密封系统中监测了这些细菌的 PAH 降解活性。结果表明，未灭菌叶片上的叶际细菌能够增强叶片对菲去除的活性。在植物种类之间进行比较时，菲的去除效率与菲降解细菌的大小相对应。此外，五桠果叶际细菌能够在 60 毫升玻璃小瓶和 14 升玻璃室中减少其他 PAHs，如苊烯、苊和氟。因此，观赏植物上的叶际细菌可能在城市空气中 PAHs 的自然衰减中发挥重要作用。
