Phytoremediation, or the use of plants for removal and detoxification of environmental pollutants, has garnered great attention in recent years. This heightened interest is both scientific, due to the fascinating processes utilized by plants for tolerance and removal of harmful compounds, and commercial, as plants provide a more environmentally compatible and less expensive alternative for site remediation compared to standard approaches.

We have recently completed a broad survey of native Michigan plants for concurrent decontamination of a polyaromatic hydrocarbon (PAH)-impacted site and restoration of the native habitat. In addition to analysis of the selected plant species, we have isolated a large number of microbes from these soils capable of degradation of PAHs and production of biosurfactants, leading to development of additional novel biotechnological approaches in our research program.

In another project, we genetically engineered a variety of plant species with the bacterial mercury detoxification genes, merA and merB. Mercury resistance in transgenic plants was shown to be due to enzymatic conversion of ionic and organic mercurials to greatly detoxified elemental mercury. Recent production of mer-transformed wetland plant species could allow treatment of the most widespread and hazardous mercury polluted sites, while promoting conditions to prevent the creation and discharge of organomercurials.

These two approaches represent very different strategies within the field of phytoremediation. Consideration of the rationale for each project offers insight into the range of benefits that plants may provide for distinct environmental needs.