SBIR PHASE I: Enhanced Subsurface Injection of Chlorinated Solvent Degrading Microorganisms

这个小企业创新研究第一阶段项目将探索处理地下环境（如含水层）中氯化溶剂污染的方法。氯化溶剂，如三氯乙烯（TCE），是特别普遍的含水层污染物。根据污染程度的不同，它们的物理性质可能导致它们以dnapl的形式出现并吸附到含水层沉积物中，这使得它们难以通过泵送处理的方法进行修复。对于这些共代谢污染物，原生细菌群体的生物降解可能由于缺乏合适的原生群体或诱导降解活性的共底物而受到限制。对于许多地点，特别是含水层污染，修复将需要生物增强或将降解细菌引入地下。ENVIROGEN开发了专门用于氯化溶剂原位修复的细菌。这些菌株黏附不足，无法加强运输；它们组成性地表达tce降解酶，不需要诱导辅底物；它们可以与大量的能量储存聚合物一起生长，以延长降解时间。然而，这些菌株的应用可能在具有广泛的DNAPL污染的位点受到限制。游离产物氯化溶剂对这些细菌有毒。为了扩大这些高度特化的生物的应用范围，我们建议将这些生物与泡沫技术结合起来，泡沫技术可以分散微生物和DNAPLs，从而降低它们的毒性。这种泡沫技术也可以提供一种提供营养和氧气的机制，以延长引入菌株的降解活性。拟议工作的成功示范将导致一种就地生物增强技术，甚至可以处理污染最严重的含水层。这项技术具有广泛的适用性；氯化溶剂是政府和私人场所常见的地下水污染物。

This Small Business Innovation Research Phase I project will explore ways to treat chlorinated solvent contamination in subsurface environments such as aquifers. Chlorinated solvents, like trichloroethylene (TCE), are particularly prevalent aquifer contaminants. Depending on the degree of contamination, their physical properties may cause them to occur as DNAPLs and sorb to aquifer sediments, which make them difficult to remediate by pump-and-treat methods. For these cometabolic contaminants, biodegradation by indigenous bacterial populations may be limited by the lack of a suitable indigenous population or inducing cosubstrates for degradative activity. For many sites, especially aquifer contamination, remediation will require bioaugmentation or the introduction of degradative bacteria into the subsurface. ENVIROGEN has developed bacteria specifically for the in situ remediation of chlorinated solvents. These strains are adhesion-deficient for enhanced transport; they express TCE-degrading enzymes constitutively, eliminating the need for inducing cosubstrates; and they can be grown with large amounts of energy storage polymers for prolonged degradation. The application of these strains, however, may be limited at sites that have extensive DNAPL contamination. Free product chlorinated solvents are toxic to these bacteria. To broaden the applications for these highly specialized organisms, we propose to combine these organisms with a foam technology which will act to disperse the microorganisms as well as the DNAPLs, thereby reducing their toxicity. This foam technology may also provide a mechanism for providing nutrients and oxygen to extend the degradative activity of the introduced strains. The successful demonstration of the proposed work will result in an in situ bioaugmentation technology for treating even the most highly contaminated aquifers. This technology is broadly applicable; chlorinated solvents are common groundwater contaminants at both government and private sites.