BIODEGRADATION OF VOLATILE ORGANIC COMPOUNDS

自然界中不同的微生物生态提供了相当大的变化 在危险废物的微生物降解途径中。这个变种 还没有理解到生物学设计所需的程度 受污染环境(场地)的补救计划。一个例子 关键的变化是微生物种群和新陈代谢的变化 随着环境氧化还原条件的变化。一些物种在 非常有限的环境，如产甲烷菌，他们不能容忍 分子氧的存在，通常与许多其他分子竞争 厌氧菌种。不同的物种能够调节不同的 以及一些类似的自然化学反应和生物反应。虽然 对这些自然反应的研究一直在进行 几十年来，人们对微生物的反应知之甚少 相对较新的人工化合物。这项提案涉及 这个问题。 拟议研究的两个主要目标是：1)增加 对溶剂可能的降解途径的了解 有利于实际实施的环境，如反硝化和 产甲烷，以及2)开发表现出增强的微生物系统 降解能力。为了实现第一个目标，两个相关 项目将研究反硝化细菌和产甲烷菌的生态 与溶剂的降解有关。反硝化菌能够 可降解的化合物，如苯和四氯化碳。然而， 人们对这种机制知之甚少；对 应用反硝化菌解决危险废物问题， 产甲烷菌也有能力脱氯卤化 溶剂。对脱氯机理及其依赖关系的认识 在初级底物和有机体物种上是必需的 了解这些化合物在环境和环境中的脂肪 设计补救方案。 第二个目标将在开发细菌菌株时实现 有能力完全销毁污染物，并且能够 在工程系统中茁壮成长。这里提出的一个项目将试图 包括定义溶剂降解能力遗传物质 特殊微生物(假单胞菌)PK01)。基因的来源 材料包括反硝化菌和产甲烷菌，如 以前的项目。开发的增强型细菌将在 实验室规模的工程系统的能力和测量其 降解率。

The diverse microbial ecology in nature provides considerable variation in pathways of microbial degradation of hazardous wastes. This variation is not understood to the degree needed for design of biological remediation programs for contaminated environments (sites). An example of critical variations is the change in microbial populations and metabolism with change in environmental redox conditions. Some species thrive in very limited environments, such as methanogens, who can not tolerate the presence of molecular oxygen and generally are out competed by many other anaerobic species. Different species are capable of mediating different and some similar natural chemical and biological reactions. Although research examining these natural reactions has been proceeding for several decades, little is known about the response of microorganisms to the relatively recent anthropogenic compounds. This proposal addresses this issue. The two major goals of the proposed research are 1) to increase understanding of the possible degradation pathways of solvents in environments conducive to actual implementation, such as denitrifying and methanogenic, and 2) to develop microbial systems that exhibit enhanced degradative ability. In order to achieve the first goal, two related projects will examine the ecology of denitrifiers and methanogens as it relates to the degradation of solvents. Denitrifiers are capable of degrading compounds such as benzene and carbon tetrachloride. However, little is known about the mechanism; information which is critical to the application of denitrifiers to solving hazardous waste problems, Methanogens also have the capability to dechlorinate halogenated solvents. Knowledge about the mechanism of dechlorination, its dependence on primary substrate and on organism species is required for understanding the fats of these compounds in the environment and for designing remediation schemes. The second goal will be achieved when development of bacterial strains capable of complete destruction of pollutants are available and able to thrive in engineered systems. One project proposed here will attempt to include genetic material which defines solvent degradative ability in a particular microorganism (Pseudomonas sp. PK01). Sources of genetic material include the denitrifiers and methanogens described in the previous projects. The enhanced bacteria developed will be tested in laboratory-scale engineered systems for its ability and to measure its degradation rate.