Bioaugmentation for chlorinated ethene detoxification: Bioaugmentation and molecular diagnostics in the bioremediation of chlorinated ethene-contaminated sites

Abstract

During the last several years, the nascent field of environmental biotechnology has advanced through the addition of specialized contaminant- degrading microorganisms that facilitate bioremediation. This process is termed bioaugmentation. Coupled with bioaugmentation has been the emergence of targeted molecular diagnostics to better engineer and manage the bioremediation process by accounting for the biological components of the contaminant attenuation process. The newly evolving paradigm is that these processes and techniques expand the options available to regulatory decision making, and thus affect contaminated-site closures. This "diagnostics and therapeutics" approach to the inventory of contaminated sites has gained traction from some federal agencies, as evidenced by significant funding initiatives that include field implementation. This paper focuses specifically on the use of bioaugmentation and molecular diagnostics in the bioremediation of chlorinated ethene-contaminated sites. We also describe a "transect" through a university-industrial process that highlights the full scope of bioremediation activities from basic research to commercialization, to successful field implementation of specialized dechlorinating microorganisms (e.g., Dehalococcoides) and the attending molecular diagnostics. A Dehalococcoides-containing consortium was developed, an efficient chlorinated ethene-detoxifying bacterium, Dehalococcoides sp. strain BAV1, was isolated, and an article of commerce was formed in the bioremediation products industry. The concomitant molecular diagnostics that identify the BAV1 organism taxonomically as well as by specific gene function (for a critical reductive dehalogenase) were also designed and commercialized. Within two years, the combined technologies have been successfully implemented at almost two dozen sites nationwide.