Nondesulfurizing benzothiophene biotransformation to hetero and homodimeric ortho-substituted diaryl disulfides by the model PAH-degrading Sphingobium barthaii
Nondesulfurizing benzothiophene biotransformation to hetero and homodimeric ortho-substituted diaryl disulfides by the model PAH-degrading Sphingobium barthaii
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DOI：
10.1007/s10532-023-10014-9
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发表时间：
2023-02
期刊：
影响因子：
3.6
通讯作者：
Y. Nemoto;K. Ozawa;Jiro F. Mori;R. Kanaly
中科院分区：
文献类型：
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作者：
Y. Nemoto;K. Ozawa;Jiro F. Mori;R. Kanaly
了解含硫多环芳烃(PASH)等有毒污染物的生物转化机理，有助于预测其环境归宿。在自然环境中，非脱硫烃降解菌是石油污染场地Pash生物降解的主要积极贡献者；然而，与脱硫菌相比，这类细菌对Bt的生物转化途径探索得较少。用定性和定量相结合的方法研究了一株非脱硫多环芳烃降解土壤细菌Sphingobium barthaiiKK22共代谢转化Bt的能力时，Bt从培养上清液中被消耗掉，但被生物转化为主要是高摩尔质量(HMM)的杂二硫化物和高二聚体邻位取代的二芳基二硫化物(二芳基二硫)。HMM二芳基二硫化物作为Bt的生物转化产物尚未见报道。通过对层析分离产物的综合质谱分析，提出了二芳基二硫化物的化学结构，并得到了包括苯硫醇在内的瞬时上游Bt生物转化产物的鉴定。还鉴定了硫代苯酸产物，并构建了描述Bt生物转化和新的HMM二芳基二硫化物形成的途径。这项工作表明，非脱硫烃降解菌从低摩尔质量的多芳硫杂环中产生HMM二芳基二硫化合物，这可以在预测Bt污染物的环境归宿时考虑在内。
Understanding the biotransformation mechanisms of toxic sulfur-containing polycyclic aromatic hydrocarbon (PASH) pollutants such as benzothiophene (BT) is useful for predicting their environmental fates. In the natural environment, nondesulfurizing hydrocarbon-degrading bacteria are major active contributors to PASH biodegradation at petroleum-contaminated sites; however, BT biotransformation pathways by this group of bacteria are less explored when compared to desulfurizing organisms. When a model nondesulfurizing polycyclic aromatic hydrocarbon-degrading soil bacterium,Sphingobium barthaiiKK22, was investigated for its ability to cometabolically biotransform BT by quantitative and qualitative methods, BT was depleted from culture media but was biotransformed into mostly high molar mass (HMM) hetero and homodimericortho-substituted diaryl disulfides (diaryl disulfanes). HMM diaryl disulfides have not been reported as biotransformation products of BT. Chemical structures were proposed for the diaryl disulfides by comprehensive mass spectrometry analyses of the chromatographically separated products and were supported by the identification of transient upstream BT biotransformation products, which included benzenethiols. Thiophenic acid products were also identified, and pathways that described BT biotransformation and novel HMM diaryl disulfide formation were constructed. This work shows that nondesulfurizing hydrocarbon-degrading organisms produce HMM diaryl disulfides from low molar mass polyaromatic sulfur heterocycles, and this may be taken into consideration when predicting the environmental fates of BT pollutants.