In vitro experiment on reducing phenanthrene accumulation in vegetable subcells with inoculation of endophytic bacteria Diaphorobacter sp.Phe15

Abstract:

[Objective]Polycyclic aromatic hydrocarbons (PAHs) in soil can be absorbed by vegetable roots and accumulated in edible parts,thus threatening human health through the food chain.Inoculation of endophytic bacteria can reduce the accumulation of PAHs in vegetables,but their effects on the accumulation of PAHs in subcellular components of vegetables are rarely reported.[Methods]In vitro experiment was carried out to study the effects of Diaphorobacter sp.Phe15 inoculation on phenanthrene accumulation in the subcellular components of water spinach as well the response of activities of enzymes related to PAHs metabolism.[Results]Diaphorobacter sp.Phe15 inoculation accelerated the degradation of phenanthrene in subcellular components of water spinach stems and leaves,and the content of phenanthrene in water spinach was significantly reduced,with the degradation rate in subcellular components reaching more than 90%.In addition,Diaphorobacter sp.Phe15 inoculation affected the activities of the enzymes related to PAHs metabolism in subcellular components of water spinach.The activities of peroxidase (POD),polyphenol oxidase (PPO) and catechol 2,3-dioxygenase (C23O) were increased overall at subcellular level,and there was a negative correlation between enzyme activities and phenanthrene accumulation in water spinach.[Conclusion]Diaphorobacter sp.Phe15 inoculation improved activities of enzymes related to PAHs metabolism,and lowered the accumulation of phenanthrene in water spinach.The results provided a certain reference and theoretical basis for the use of functional endophytic bacteria to reduce PAHs pollution in vegetables.