接种功能内生细菌Diaphorobacter sp.Phe15减少蔬菜亚细胞菲积累的体外试验研究

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

摘要:

[目的]土壤中的多环芳烃(polycyclic aromatic hydrocarbons, PAHs)可被蔬菜根系吸收并在可食部分积累进而通过食物链威胁人群健康。接种功能内生细菌能有效减低蔬菜中PAHs的积累,而关于其对蔬菜亚细胞组分中PAHs积累的影响却鲜有报道。[方法]采用体外实验,研究了接种具有菲降解功能的菌株Diaphorobacter sp. Phe15对空心菜茎叶亚细胞组分中菲积累的影响及PAHs代谢相关酶活性的响应。[结果]接种Phe15可以可加速空心菜茎叶亚细胞中菲的降解,显著削减空心菜亚细胞组分中菲的含量,接菌后空心菜亚细胞组分中菲降解率达90%以上。此外,接种功能菌Phe15可以影响空心菜亚细胞组分中PAHs代谢相关酶系的活性,空心菜亚细胞水平POD、PPO、C230活性整体得到提高,且酶系活性与空心菜体内菲积累呈负相关关系。[结论]接种具有菲降解功能的菌株Phe15增加了空心菜亚细胞水平PAHs代谢相关酶系活性,进而降低空心菜体内菲的积累,研究结果为利用功能内生细菌削减蔬菜中多环芳烃污染提供了一定的参考和理论依据。

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.