Instituto de Recursos Naturales y Agrobiología (IRNAS-CSIC) , Apartado 1052, 41080 Sevilla, Spain.
J Agric Food Chem. 2012 Oct 10;60(40):9941-7. doi: 10.1021/jf3021909. Epub 2012 Oct 1.
The phenylurea herbicide diuron [N-(3,4-dichlorophenyl)-N,N-dimethylurea] is widely used in a broad range of herbicide formulations and, consequently, it is frequently detected as a major soil and water contaminant in areas where there is extensive use. Diuron has the unfortunate combination of being strongly adsorbed by soil organic matter particles and, hence, slowly degraded in the environment due to its reduced bioavailability. N-Phenylurea herbicides seem to be biodegraded in soil, but it must be kept in mind that this biotic or abiotic degradation could lead to accumulation of very toxic derived compounds, such as 3,4-dichloroaniline. Research was conducted to find procedures that might result in an increase in the bioavailability of diuron in contaminated soils, through solubility enhancement. For this purpose a double system composed of hydroxypropyl-β-cyclodextrin (HPBCD), which is capable of forming inclusion complexes in solution, and a two-member bacterial consortium formed by the diuron-degrading Arthrobacter sulfonivorans (Arthrobacter sp. N2) and the linuron-degrading Variovorax soli (Variovorax sp. SRS16) was used. This consortium can achieve a complete biodegradation of diuron to CO2 with regard to that observed in the absence of the CD solution, where only a 45% biodegradation was observed. The cyclodextrin-based bioremediation technology here described shows for the first time an almost complete mineralization of diuron in a soil system, in contrast to previous incomplete mineralization based on single or consortium bacterial degradation.
苯脲类除草剂敌草隆[N-(3,4-二氯苯基)-N,N-二甲基脲]广泛应用于多种除草剂配方中，因此，在广泛使用的地区，它经常被检测为主要的土壤和水污染物质。敌草隆具有很强的被土壤有机质颗粒吸附的不幸组合，因此，由于其生物利用度降低，在环境中降解缓慢。N-苯基脲类除草剂似乎在土壤中被生物降解，但必须记住，这种生物或非生物降解可能导致非常有毒的衍生化合物的积累，如 3,4-二氯苯胺。研究旨在通过提高溶解度来寻找可能增加受污染土壤中敌草隆生物利用度的程序。为此，使用了由羟丙基-β-环糊精（HPBCD）组成的双系统，HPBCD 能够在溶液中形成包合络合物，以及由敌草隆降解菌节杆菌（Arthrobacter sp. N2）和利谷隆降解菌土壤芽孢杆菌（Variovorax sp. SRS16）组成的二成员细菌联合体。与没有 CD 溶液时观察到的情况相比，该联合体可以实现敌草隆完全生物降解为 CO2，而在没有 CD 溶液时仅观察到 45%的生物降解。这里描述的基于环糊精的生物修复技术首次在土壤系统中实现了敌草隆的几乎完全矿化，与以前基于单一或联合体细菌降解的不完全矿化形成对比。
