The impact of low molecular weight organic acids from plants with C3 and C4 photosystems on the rhizoremediation of polycyclic aromatic hydrocarbons contaminated soil

Abstract This study evaluated the role of the low molecular weight organic acids (LMWOAs) from the root exudates of C3 (sunflower and wallaby grass) and C4 (maize, Sudan grass, and vetiver) plants on the degradation of Polycyclic aromatic hydrocarbons (PAHs). The LMWOAs that were detected from the rhizospheres of C3 and C4 plants were aconitic, citric, lactic, malic, malonic, succinic and oxalic acids. A greater difference in the quantity of LMWOAs was observed between selected C3 and C4 plants. Among the LMWOAs detected in C3 and C4 plants, the concentration of citric acid was correlated significantly with high PAHs degradation percentage, followed by succinic and aconitic acid in both C3 and C4 plants. The results of this study indicated that the LMWOAs from the selected C4 plants have a greater influence on the PAHs degradation than the C3 plants.