Reductive Biotransformation Of2,4-Dinitrotoluene And Pendimethalin By Shewanella Marisflavi EP1Under Anaerobic Conditions

2,4-dinitrotoluene(2,4-DNT) is an important intermediate in production procedure of toluenediamine, pesticides, rubber, polyurethane and dye. In recent years, with the rapid development of chemical industry, the demand for2,4-DNT siginificantly dramatically increased. Irrational emissions will inevitably aggravate the environmental pollution. Due to potential risk of the DNT and its transformation products to human and ecological environment, the treatment of wastewater contaminated DNT has attracted much more attention. In addition, as dinitroaniline pre-emergence herbicide, pendimethalin is extensively used in agriculture, its environmental persistence has caused wide concern. To better understand the environmental fate of2,4-DNT and pendimethalin under anaerobic conditions, we studied their efficiency of reductive transformation by Shewanella marisflavi EP1, also evaluated the effects of various environmental factors on this transformation. Using2,4-DNT and pendimethalin as the sole electron acceptor respectively, lactate as the electron donor and EP1as degrader, the cell growth and the reduction of2,4-DNT and pendimethalin were measured in the different systems.The results showed that the degradation of2,4-DNT and pendimethalin by EP1was effective under anaerobic conditions. The transformation rate increased in the presence of riboflavin, while the reduction reaction is delayed or even completely inhibited by adding respiratory inhibitors, such as Cu, dicumarol and metyrapone, those indicate that transformation of2,4-DNT and pendimethalin is linked to the electron transport chain of the microbial anaerobic respiration. The optimal conditions of2,4-DNT reduction by EP1were:pH9.0,40℃and2%salinity, respectively. And the optimal conditions for pendimethalin reduction by EP1were:pH8.0,35℃and2%salinity, respectively Our findings not only expand the potential range of electron acceptor respirated by Shewanella but also provide experimental basis for remediation of nitro compounds contamination.