稳定同位素技术在污染环境生物修复研究中的应用

稳定同位素技术主要应用于地球化学,它是将人工合成的同位素标记特定的化合物,追踪标记物在生命活动中的变化规律,目前该项技术也广泛应用于环境微生物学、生态学、生物医学等领域.生物修复是利用存在于土壤、地下水和海洋等环境中的生物特别是微生物将有毒、有害的污染物降解为二氧化碳和水,或转化为无害物质,从而使污染的生态环境修复为正常生态环境的过程.这些降解微生物都来自于小部份可培养微生物,对于大部份未可培养降解微生物,通常在实验室条件下很难得到.而利用稳定同位素技术,如13C标记底物,收集利用该底物的微生物核酸,就可以得到具有降解作用的功能微生物,为环境污染生物修复提供重要的菌源和功能基因.环境中的许多物质都可以用SIP来标记,这些标记物主要有PLFA-SIP、DNA-SIP、RNA-SIP等,它们都可以用来在复杂样本中进行有特殊代谢功能微生物的鉴定和分析,在利用微生物进行生物修复中具有重要的意义.图2表1参42

Application of Stable Isotope Probing in Bioremediation of Polluted Environment

Stable isotope probing (SIP) has been widely applied in geochemistry, which uses special organic chemicals having been labeled by man-made SIP to explore diversifications of the labeled compounds in life process. At present, SIP is also used in many fields, such as environmental microbiology, ecology and biological medicine. Bioremediation is a process that the polluted ecological environment is remediated into normal ecological environment, and the toxic and harmful pollutants are degraded into carbon dioxide and water, or transformed into harmless compounds by organisms, especially the microorganisms existing in soil, underground water, sea water and so on. These microbes capable of degrading organic pollutants only come from a small portion of cultivable microbes, but a large portion of uncultured ones cannot be obtained easily under lab conditions. If SIP, such as 13C labeled substrates, is used, the correlated degrading genes can be obtained by collection of nucleic acid in microbes utilizing those substrates, and at the same time, the important microbial sources and their functional genes can be provided for the bioremediation of the pollutants. Many materials in the environment can be labeled with SIP, including PLFA-SIP, DNA-SIP and RNA-SIP. All the methods can be used to identify and analyze functional microbes, and they are greatly significant for bioremediation. Fig 2, Tab 1, Ref 42