Colonization of polycyclic aromatic hydrocarbon-degrading bacteria on roots reduces the risk of PAH contamination in vegetables. (November 2019) - Chen, Shuang
Abstract: This is a primary investigation on the mitigation of polycyclic aromatic hydrocarbon (phenanthrene as a model PAH) contamination in vegetables including water spinach ( Ipomoea aquatica Forsk), pakchoi ( Brassica campestris ) and Chinese cabbage ( Brassica chinensis ) using a gfp -labeled PAH-degrading bacterium (RS1- gfp ). Effective root colonization led to dense RS1- gfp populations inhabiting the rhizosphere and endosphere of the vegetables, which subsequently led to a reduction in phenanthrene accumulation and risk in vegetables. When compared with the controls without RS1- gfp, the amount of phenanthrene accumulation due to strain RS1- gfp colonization reduced by up to ~93.7% in roots and ~75.2% in shoots of vegetables, respectively. The estimated incremental lifetime cancer risk (ILCR) for adults due to phenanthrene in vegetables was reduced by 24.6%–48% through RS1- gfp inoculation. The proposed method was developed to circumvent the risk of phenanthrene contamination in vegetables by inoculating PAH-degrading bacteria. The findings provide an in-depth understanding of PAH detoxification in agricultural plants grown on contaminated sites by exploiting bacteria like RS1- gfp, which portray both rhizo- and endophytic lifestyles. Graphical abstract: Unlabelled Image Highlights: The isolated strain RS1- gfp is capable of degrading phenanthrene. Root colonization led to dense populations of RS1- gfp on roots and internal vegetable tissues. RS1- gfp colonization reduced the concentration and accumulation of phenanthrene in vegetables. RS1- gfp can effectively mitigate the risks of vegetable phenanthrene contamination.