Prediction of the Formation of Biogenic Nonextractable Residues during Degradation of Environmental Chemicals from Biomass Yields.
Prediction of the Formation of Biogenic Nonextractable Residues during Degradation of Environmental Chemicals from Biomass Yields.
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DOI：
10.1021/acs.est.7b04275
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发表时间：
2018-01
影响因子：
11.4
通讯作者：
S. Trapp;A. Brock;K. Nowak;M. Kästner
中科院分区：
文献类型：
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作者：
S. Trapp;A. Brock;K. Nowak;M. Kästner
用放射性或稳定同位素标记的化合物进行降解试验，可以检测不可提取残留物（NER）的形成。在PBT和vPvB评估中，可移动的NER被认为是一种潜在的风险，而标记碳进入微生物生物量的生物源性NER被视为降解产物。产量、释放的CO2（作为微生物活动和矿化的指标）和微生物生长之间的关系可以用来估计生物源性NER的形成。我们提供了一种基于吉布斯自由能和微生物有效电子计算底物转化为微生物生物量（理论产率）的新方法。我们比较了生物技术底物和环境化学品的估计理论产量与实验确定的产量，以验证所提出的方法。采用五室动态模型模拟13c标记的2,4- d和布洛芬周转实验。结果表明，bioNER随着时间的推移而增加，且大部分bioNER来源于微生物蛋白。用预计算输入数据进行的仿真表明，预计算产率大大减少了拟合参数的数量，提高了拟合动力学数据的置信度，降低了仿真结果的不确定性。
Degradation tests with radio or stable isotope labeled compounds enable the detection of the formation of nonextractable residues (NER). In PBT and vPvB assessment, remobilisable NER are considered as a potential risk while biogenic NER from incorporation of labeled carbon into microbial biomass are treated as degradation products. Relationships between yield, released CO2 (as indicator of microbial activity and mineralization) and microbial growth can be used to estimate the formation of biogenic NER. We provide a new approach for calculation of potential substrate transformation to microbial biomass (theoretical yield) based on Gibbs free energy and microbially available electrons. We compare estimated theoretical yields of biotechnological substrates and of chemicals of environmental concern with experimentally determined yields for validation of the presented approach. A five-compartment dynamic model is applied to simulate experiments of 13C-labeled 2,4-D and ibuprofen turnover. The results show that bioNER increases with time, and that most bioNER originates from microbial proteins. Simulations with precalculated input data demonstrate that precalculation of yields reduces the number of fit parameters considerably, increases confidence in fitted kinetic data, and reduces the uncertainty of the simulation results.