Models of 2,4,6-trinitrotoluene (TNT) initial conversion by yeasts
- 作者：Zaripov ; S.A. ; Naumov ; A.V. ; Abdrakhmanova ; J.F. ; Garusov ; A.V. ; Naumova ; R.P.
- 关键词：2 ; 4 ; 6-Trinitrotoluene ; Initial transformation ; Reactive metabolite ; Yeast ; Toxicity ; Explosives and oil contamination
- 刊名：FEMS Microbiology Letters
- 出版年：2002
- 期刊代码：34_03781097
- 类别：imm
- 出版时间：December 17, 2002
- 卷：217
- 期：2
- 页码：213-217
- 文件大小：198 K
摘要
The original models of the initial steps of 2,4,6-trinitrotoluene (TNT) conversion by yeasts are presented. Saccharomyces sp. ZS-A1 reduced nitro groups of TNT producing isomeric monohydroxylaminodinitrotoluenes (HADNT) as the key initial metabolites (molar ratio HADNT/TNT was up to 0.81), whereas aminodinitrotoluenes (ADNT) and the hydride–Meisenheimer complex of TNT (H-TNT) were the minor products. Conversely, Candida sp. AN-L13 transformed TNT almost quantitatively into H-TNT, thus realizing the alternative attack, consisting of the TNT aromatic ring reduction. The third type of conversion, revealed in Candida sp. AN-L14, is the combination of both above mechanisms and produces an equimolar mix of HADNT and H-TNT. In the toxicity tests with Paramecium caudatum, the supernatant of Saccharomyces sp. ZS-A1, which converts TNT into HADNT, was most toxic while the supernatant of Candida sp. AN-L13 (TNT→H-TNT) was least toxic. The microorganisms converting TNT quantitatively to the reactive metabolites can be useful for their immobilization through the detoxifying interaction with the soil components such as humic compounds.