Bioremediation Bacteria to Protect Plants in Pentachlorophenol‐Contaminated Soil

Abstract

Plants may be useful in stabilization and remediation of polluted surface soils, but phytotoxicity and plant bioconcentration of some pollutants can interfere with plant-associated site remediation. Pseudomonas strain SR3, when applied to seeds of proso millet (Panicum miliaceum L.), protected the growing plants from phytotoxicity of pentachlorophenol (PCP) in the soil during a 4-wk growth-chamber study. Untreated plants in the contaminated soil grew very poorly. In soil receiving the bacteria-treated seed, PCP was reduced from 175 mg/kg to 3 mg/kg. When bacteria were mixed thoroughly into the soil at 5 × 106 cfu/g, in the absence of plants, PCP was likewise reduced from 175 to 5 mg/kg. PCP in soil with noninoculated plants remained at the initial level (165 mg/kg extractable PCP). Roots without applied bacteria concentrated PCP from the soil into root tissue to a ratio of 13:1 (final root concentration/initial soil concentration), whereas the bacteria-treated roots concentrated PCP at a ratio of 0.09:1.