Enhanced endophyte:poplar system for remediation of organic contaminants

描述（由申请人提供）：三氯乙烯（TCE）是一种已知的肝毒素和致癌物，是最常见的地下水污染物之一。它被工业和军队广泛用作金属部件的脱脂剂：根据有毒物质和疾病登记处的数据，美国有800多个超级基金场所受到TCE的污染。杨树可吸收和降解TCE，由于其生长速度快、根系粗大、土壤吸水率高、易于遗传操作等优点，是修复TCE和其他有机污染物的理想植物。虽然转基因杨树改善TCE降解已经成功地进行了田间试验，但存在重大的监管和育种障碍，阻碍了该技术的大规模使用。近年来，研究人员已经确定了植物细胞内的内生菌、共生细菌和真菌在分解有机污染物和提高非转基因植物修复能力方面的潜力。与其他用于植物修复的微生物不同，内生菌生活在植物内部，因此有望在现场更好地持续存在，只要它们的植物伴侣存活，就会继续降解TCE。Sharon Doty博士的实验室是研究内生菌促进植物生长和健康的先驱之一，在这一领域工作了十多年。最近，她的实验室从生长在受TCE和其他有机污染物污染的地方的杨树中分离出内生菌。当在实验室中生长时，其中一些微生物表现出高的TCE降解率。她的实验室目前正在研究将这些降解TCE的内生菌接种到杨树中的方法，并将与Edenspace合作开展SBIR项目，以证明新的杨树/内生菌系统比对照杨树具有明显更好的TCE植物修复性能。Edenspace还将开发分子标记来识别特定的内生菌，以便在现场测试中确认微生物可以在杨树中存活数月。在SBIR项目成功完成后，Edenspace将与领先的环境工程公司Geosyntec合作，将这项新技术引入修复行业。

DESCRIPTION (provided by applicant): Trichloroethylene (TCE), one of the most common groundwater pollutants, is a known hepatotoxin and carcinogen. It has been widely used by industry and the military as a degreaser for metal parts: according to the Agency for Toxic Substances and Disease Registry, more than eight hundred Superfund sites in the United States are contaminated with TCE. Poplar, which can take up and degrade TCE, is an attractive plant for phytoremediation of TCE and other organic contaminants due to its high growth rate, extensive root system, high rates of water uptake from the soil, and ease of genetic manipulation. While transgenic poplar for improved TCE degradation has been successfully field tested, there are significant regulatory and breeding hurdles preventing the large-scale use of this technology. Recently researchers have determined the potential of endophytes, symbiotic bacteria and fungi that live within plant cells, to break down organic contaminants and improve the phytoremediation capability of non-transgenic plants. Unlike other microbes that have been used for phytoremediation, endophytes live within the plant and therefore are expected to persist better at the site, continuing to degrade TCE as long as their plant partner survives. The laboratory of Dr. Sharon Doty is one of the pioneers in studying endophytes to improve plant growth and health, having worked in this field for over a decade. Recently her laboratory has isolated endophytes from poplar growing in sites contaminated with TCE and other organic pollutants. Some of these microbes exhibit high rates of TCE degradation when grown in the lab. Her laboratory is currently developing methods to inoculate these TCE-degrading endophytes into poplar and will work with Edenspace on this SBIR project to demonstrate that the new poplar/endophyte systems have significantly better TCE phytoremediation performance than control poplar. Edenspace will also develop molecular markers to identify the specific endophytes, in order to confirm in a field test that the microbes can persist in the poplar for months. Upon successful completion of this SBIR project Edenspace will partner with Geosyntec, a leading environmental engineering firm, to introduce this novel technology to the remediation industry. PUBLIC HEALTH RELEVANCE: Trichloroethylene (TCE) is a known carcinogen and significant environmental contaminant as a result of to extensive use by the military and industry. Poplar trees have been used as a natural method to remove TCE from contaminated groundwater. In this project scientists from Edenspace and the University of Washington will utilize recently identified microbes that can act with the poplar to greatly increase TCE removal rates. Development of this improved remediation system will reduce exposure of humans and wildlife to TCE.