کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5747939 1618926 2017 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Enhancement of microbial 2,4,6-trinitrotoluene transformation with increased toxicity by exogenous nutrient amendment
ترجمه فارسی عنوان
افزایش ترشح میکروبی 2،4،6-ترینیتروتوولول با افزایش سمیت توسط اصلاح مواد مغذی خارجی
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم محیط زیست شیمی زیست محیطی
چکیده انگلیسی


- Amino nitrogen amendment greatly enhances TNT degradation by Citrobacter sp.
- Amino nitrogen cometabolism inducing nitroreductases enhances TNT degradation.
- TNT transformation product mixture is more toxic on Tigriopus japonicas than TNT.

In this study, the bacterial strain Citrobacter youngae strain E4 was isolated from 2,4,6-trinitrotoluene (TNT)-contaminated soil and used to assess the capacity of TNT transformation with/without exogenous nutrient amendments. C. youngae E4 poorly degraded TNT without an exogenous amino nitrogen source, whereas the addition of an amino nitrogen source considerably increased the efficacy of TNT transformation in a dose-dependent manner. The enhanced TNT transformation of C. youngae E4 was mediated by increased cell growth and up-regulation of TNT nitroreductases, including NemA, NfsA and NfsB. This result indicates that the increase in TNT transformation by C. youngae E4 via nitrogen nutrient stimulation is a cometabolism process. Consistently, TNT transformation was effectively enhanced when C. youngae E4 was subjected to a TNT-contaminated soil slurry in the presence of an exogenous amino nitrogen amendment. Thus, effective enhancement of TNT transformation via the coordinated inoculation of the nutrient-responsive C. youngae E4 and an exogenous nitrogen amendment might be applicable for the remediation of TNT-contaminated soil. Although the TNT transformation was significantly enhanced by C. youngae E4 in concert with biostimulation, the 96-h LC50 value of the TNT transformation product mixture on the aquatic invertebrate Tigriopus japonicas was higher than the LC50 value of TNT alone. Our results suggest that exogenous nutrient amendment can enhance microbial TNT transformation; however, additional detoxification processes may be needed due to the increased toxicity after reduced TNT transformation.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ecotoxicology and Environmental Safety - Volume 138, April 2017, Pages 39-46
نویسندگان
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