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此文档是毕业设计外文翻译成品( 含英文原文+中文翻译),无需调整复杂的格式!下载之后直接可用,方便快捷!本文价格不贵,也就几十块钱!一辈子也就一次的事!外文标题:Individual or synchronous biodegradation of di-n-butyl phthalate and phenol by Rhodococcus ruber strain DP-2.外文作者:Z He , C Niu , Z Lu文献出处:Journal of Hazardous Materials , 2018 , 273 (3) :104-109(如觉得年份太老,可改为近2年,毕竟很多毕业生都这样做)英文2903单词,17889字符(字符就是印刷符),中文4658汉字。原文:Individual or synchronous biodegradation of di-n-butyl phthalate and phenol by Rhodococcus ruber strain DP-2.h i g h l i g h t sA Rhodococcus ruber strain degraded DBP and phenol.Degradation kinetics of DBP or phenol fit modified first-order models.Degradation interaction between DBP and phenol was studied by strain DP-2.The degradation genes transcriptional were quantified by RT-qPCR.a b s t r a c tThe bacterial strain DP-2, identified as Rhodococcus ruber, is able to effectively degrade di-n-butyl phthalate (DBP) and phenol. Degradation kinetics of DBP and phenol at different initial concentrations revealed DBP and phenol degradation to fit modified first-order models. The half-life of DBP degradation ranged from 15.81 to 27.75 h and phenol degradation from 14.52 to 45.52 h under the initial concentrations of6001200 mg/L. When strain DP-2 was cultured with a mixture of DBP (800 mg/L) and phenol (700 mg/L),DBP degradation rate was found to be only slightly influenced; however, phthalic acid (PA) accumulated, and phenol degradation was clearly inhibited during synchronous degradation. Transcriptional levelsof degradation genes, phenol hydroxylase (pheu) and phthalate 3,4-dioxygenase (pht), decreased significantly more during synchronous degradation than during individual degradation. Quantitative estimation of individual or synchronous degradation kinetics is essential to manage mixed hazardous compounds through biodegradation in industrial waste disposal.IntroductionHuman industrial activities generate huge amounts of industrial waste containing different hazardous organic pollutants, and the capability of bacteria to mineralize these toxic chemicals from industrial waste environments depends substantially on the presence of other compounds. Phthalate esters (PAEs) and phenolsare two widely produced families of chemicals used to stabilizeand modify the characteristics and performance of polymers 1in industry, and currently, large amounts of these chemicals are released into environments. Di-n-butyl phthalate (DBP), one of the most commonly used PAEs, is also used in various other products, such as insecticides, packaging materials, cosmetics, coverings, clothes and insulators in electric disposals 2. Phenol, one of the basal phenols, is a major pollutant that can be employed in many industrial processes such as the production of polycarbonate resins, nylon, plastics, oil refineries, and pharmaceuticals 3. Simultaneous monitoring of phenols and PAEs has been reported in the river basin 4. Compared with the toxicity of individual chemicals, combined disposal of PAEs and phenols could induce increased lactate dehydrogenase release from Sertoli cells 5. Therefore, the additive toxic effect of two substances on cells generates pollutants that are quite recalcitrant to synchronous degradation by bacterialcells. Further quantitative estimation of individual or synchronousdegradation kinetics is essential to remove mixed hazardous com-pounds through biodegradation.Biodegradation processes of a mixture are known as interactions existing among toxic compounds 6,7. The metabolic activity of the biodegradation of two or more pollutants may involveco-metabolism 8, induction of required enzymes 9 or negative interactions 10, which depend on the different compounds, the presence of microbial species, and compound concentrations. DBP and phenol are two widely used industrial chemicals; DBP has low water solubility and high octanol/water partition coefficients, whereas phenol is water soluble and highly mobile. Different water solubility of two compounds might have an impact on the biodegradability of each compound when they co-exist. However, studies on the synchronous biodegradation of DBP andphenol are rare. Members of the Rhodococcus genus, one of the most promising groups of G+bacteria existing in the natural environment, have been isolated, identified and applied for toxic compound biodegradation. Some previous authors have reported that Rhodococcus sp.could be involved in DBP 1113 or phenol 1417 degradation individually. However, only one study found that Rhodococcus sp.had potential to mineralize DBP and phenol 18. The degradation pathway of DBP in G+bacteria involves initially converting DBPinto phthalic acid (PA), and subsequently PA is attacked by 3,4-dihydroxyphthalate forming protocatechuate (PCA) 19. Phenol degradation is mainly accompanied by the formation of catechol,which further undergoes cleavage in the meta-position or ortho-position of the cyclobenzene 20.In this study, a
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