Endophytic Phytoaugmentation: Treating Wastewater and Runoff Through Augmented Phytoremediation

Abstract

Limited options exist for efficiently and effectively treating water runoff from agricultural fields and landfills. Traditional treatments include excavation, transport to landfills, incineration, stabilization, and vitrification. In general, treatment options relying on biological methods such as bioremediation have the ability to be applied in situ and offer a sustainable remedial option with a lower environmental impact and reduced long-term operating expenses. These methods are generally considered ecologically friendly, particularly when compared to traditional physicochemical cleanup options. Phytoremediation, which relies on plants to take up and/or transform the contaminant of interest, is another alternative treatment method which has been developed. However, phytoremediation is not widely used, largely due to its low treatment efficiency. Endophytic phytoaugmentation is a variation on phytoremediation that relies on augmenting the phytoremediating plants with exogenous strains to stimulate associated plant-microbe interactions to facilitate and improve remediation efficiency. In this review, we offer a summary of the current knowledge as well as developments in endophytic phytoaugmentation and present some potential future applications for this technology. There has been a limited number of published endophytic phytoaugmentation case studies and much remains to be done to transition lab-scale results to field applications. Future research needs include large-scale endophytic phytoaugmentation experiments as well as the development of more exhaustive tools for monitoring plant-microbe-pollutant interactions.

Phytoremediation of Heavy Metal-Contaminated Sites: Eco-environmental Concerns, Field Studies, Sustainability Issues, and Future Prospects

“…In this technology, the remediating plants are augmented with potential endophytes for the balanced plant-microbe interactions and enhanced remediation efficiency. However, the slow action, season dependent effectiveness and lack of suitable monitoring methods are the key associated constraints that need to be addressed in the future for a successful application (Redfern and Gunsch 2016).…”

Enhanced Degradation of TCE on a Superfund Site Using Endophyte-Assisted Poplar Tree Phytoremediation

“…Phytoremediation can be potentially improved by using genetic engineering and by bioaugmenting with pollutant-degrading bacteria. − Transgenic trees − and other suitable phytoremediation plant species , engineered to overexpress key enzymes can potentially have substantially improved pollutant detoxification and removal. Alternatively, partnering plants with effective pollutant-degrading microorganisms has also shown promise, and research in this area has increased dramatically in the past decade demonstrating near-term application potential without the need for the high-cost and lengthy deployment process associated with transgenic plants.…”

“…62−65 Despite these numerous lab or greenhouse-based studies, there are few reports of field trials of endophyte-assisted phytoremediation. 26 The in situ addition of a poplar root endophyte strain engineered to degrade TCE resulted in reduced evapotranspiration of TCE. 66 However, no direct evidence was provided on increased removal of groundwater TCE or degradation of TCE in planta.…”