New Approaches for Bioaugmentation as a Remediation Technology

Bioaugmentation is commonly employed as a remediation tech-nology. However, numerous studies indicate that introduced mi-croorganisms often do not survive in the environment and thus do not increase contaminant remediation. This review details sev-eral new approaches that may increase the persistence and activity of exogenous microorganisms and/or genes following introduction into the environment. These techniques include: (1) bioaugmen-tation with cells encapsulated in a carrier such as alginate; (2) gene bioaugmentation where the goal is for the added inocu-lant to transfer remediation genes to indigenous microorganisms; (3) rhizosphere bioaugmentation where the microbial inoculant is added to the site along with a plant that serves as a niche for the inoculant’s growth; and (4) phytoaugmentation where the reme-diation genes are engineered directly into a plant for use in re-mediation without a microbial inoculant. Additionally, the review discusses the generation of genetically engineered microorganisms for use in bioaugmentation along with methods for the control of the engineered microorganisms in the environment, and the potential effects of the release on indigenous organisms. Various methods for the detection of introduced microorganisms such as real-time poly-merase chain reaction (PCR) and reporter genes are also addressed. Ultimately, these new approaches may broaden the application of bioaugmentation as a remediation technology.