SBIR Phase I: Improved Biocatalyst for Methyl Tert-Butyl Ether (MTBE) Degradation

*9760044 Steffan这个为期6个月的SBIR第一阶段项目涉及开发用于破坏汽油含氧物的改进生物催化剂，如甲基叔丁基醚、乙基叔丁基醚和叔戊基甲醚。自20世纪70年代末以来，美国一直在汽油中添加MTBE等含氧物，以取代铅和其他有毒成分。目前，MTBE在美国生产的有机化学品名单上排名第二，年产量超过240亿磅，已成为城市地下水最常见的污染物之一。最近对地下水污染的担忧导致一些州将地下水中MTBE的最高允许水平降低到100ppb。关于MTBE生物降解的少数研究取得的成功非常有限，从而得出结论，MTBE对生物降解是顽固的。然而，Envigen最近的研究发现了一类可以生物降解MTBE的微生物，但不能将其用作生长底物。这项拟议工作的目标是利用现代分子生物学技术利用迄今收集的知识来开发一种可以作为碳和能源的唯一来源在MTBE上生长的生物体。在该项目期间开发的技术将适用于破坏各种废水中的汽油含氧物，包括地下水修复和管道末端处理。最初，这项技术将部署在受控生物反应器中，最终在证明生物催化剂的安全性后，就地部署。已向监管机构报告了30多万个汽油储罐泄漏，其中许多地点含有受MTBE污染的地下水。由于缺乏MTBE的替代补救办法，拟议的工作具有重要的商业意义。***

*** 9760044 Steffan This 6 month Phase I SBIR project involves the development of improved biocatalysts for destroying gasoline oxygenates such as methyl tert-butyl ether (MTBE), ethyl tert butyl ether (ETBE), and tert-amyl methyl ether (TAME). Oxygenates such as MTBE have been added to gasoline in the United States since the late 1970@, to replace lead and other toxic components. Currently, MTBE is second on the list of organic chemicals produced in the United States with greater than 24 billion pounds produced annually, and it has become one of the most common contaminants of urban groundwaters. Recent concern over groundwater contamination has led some states to reduce their allowable maximum levels of MTBE in groundwater to 100 ppb. The few studies that have addressed MTBE biodegradation have met with very limited success, thereby leading to the conclusion that MTBE is recalcitrant to biodegradation. Recent studies by Envirogen, however, have identified a class of microorganisms that can biodegrade MTBE, but can not use it as a growth substrate. The goal of the proposed work is to use modern molecular biological techniques to exploit knowledge gathered to date to develop an organisms that can grow on MTBE as a sole source of carbon and energy. The technology developed during this project will be applicable for destroying gasoline oxygenates in a variety of wastewaters including groundwater remediation and end-of-pipe treatment. Initially, the technology will be deployed in contained bioreactors, and eventually, upon deomonstrating the safety of the biocatalysts, in situ. More than 300,000 leaking gasoline storage tanks have been reported to regulatory agencies, and many of these sites contain MTBE-contaminated groundwater. The lack of alternative remediation alternatives for MTBE makes the proposed work commercially significant. ***