微生物降解甲基叔丁基醚及其关键酶的研究进展

Biodegradation of methyl tert-butyl ether (MTBE) and key enzymes

为了减少机动车排放的CO和O3等污染气体,提高汽油的辛烷值,甲基叔丁基醚(MTBE)作为燃料氧化剂而广泛应用于汽油中。与此同时,由于MTBE具有很高的水溶性和难降解性,使用过程中的泄露带来了严重的污染问题。其自身的化学特性也给去除环境中的MTBE增添了很多困难。生物降解是土壤地下水修复中公认的有效又可以节省成本的方法。国外已经报道MTBE能在好氧或厌氧的条件下被微生物通过直接代谢或共代谢的方式而降解,国内在此方面的研究刚刚开始,尤其在降解机理方面的研究还存在很大的空白。本文对能够降解MTBE的微生物进行了总结,并且重点阐述了在MTBE降解过程中起作用的关键酶。

As a fuel oxidizing agent, methyl tert-butyl ether （MTBE） is added to gasoline in replacement of tetraethyl lead to enhance octane number. The addition of MTBE also improves the combustion efficiency and therefore decreases the emission of pollutants like CO and O3. On the other hand, because of gasoline spills, mainly due to leaking underground storage tanks, MTBE has become a prevalent contaminant in groundwater. The reason for such widespread contamination is that MTBE is highly soluble in water and recalcitrant to biodegradation. The chemical characteristics of MTBE make it a challenge to treatment in the natural environment. Biological treatment of soil and groundwater is expected to be a cost-effective technique. It was reported that MTBE was able to degrade through co-oxidation or could be used as a carbon and energy source by many microorganisms. In China, the studies on MTBE removal by bioremediation techniques are still at their infancy for both fundamental research and on-site application. Based on previous studies, the reported microorganisms able to degrade MTBE were summarized, and then emphasis was put on the key catabolic enzymes involved in MTBE degradation.