Chen Yan-Min, Lin Tsair-Fuh, Huang Chih, Lin Jui-Che
Department of Environmental Engineering and Sustainable Environment Research Center, National Cheng Kung University, Tainan City 70101, Taiwan, ROC.
Chemosphere. 2008 Aug;72(11):1671-80. doi: 10.1016/j.chemosphere.2008.05.035. Epub 2008 Jun 30.
Modeling of cometabolic kinetics is important for better understanding of degradation reaction and in situ application of bio-remediation. In this study, a model incorporated cell growth and decay, loss of transformation activity, competitive inhibition between growth substrate and non-growth substrate and self-inhibition of non-growth substrate was proposed to simulate the degradation kinetics of phenol and trichloroethylene (TCE) by Pseudomonas putida. All the intrinsic parameters employed in this study were measured independently, and were then used for predicting the batch experimental data. The model predictions conformed well to the observed data at different phenol and TCE concentrations. At low TCE concentrations (<2 mg l(-1)), the models with or without self-inhibition of non-growth substrate both simulated the experimental data well. However, at higher TCE concentrations (>6 mg l(-1)), only the model considering self-inhibition can describe the experimental data, suggesting that a self-inhibition of TCE was present in the system. The proposed model was also employed in predicting the experimental data conducted in a repeated batch reactor, and good agreements were observed between model predictions and experimental data. The results also indicated that the biomass loss in the degradation of TCE below 2 mg l(-1) can be totally recovered in the absence of TCE for the next cycle, and it could be used for the next batch experiment for the degradation of phenol and TCE. However, for higher concentration of TCE (>6 mg l(-1)), the recovery of biomass may not be as good as that at lower TCE concentrations.
共代谢动力学建模对于更好地理解降解反应和生物修复的原位应用非常重要。在本研究中，提出了一个包含细胞生长与衰亡、转化活性丧失、生长底物与非生长底物之间的竞争性抑制以及非生长底物的自我抑制的模型，以模拟恶臭假单胞菌对苯酚和三氯乙烯（TCE）的降解动力学。本研究中使用的所有内在参数均独立测量，然后用于预测间歇实验数据。在不同的苯酚和TCE浓度下，模型预测与观测数据吻合良好。在低TCE浓度（<2 mg l(-1)）时，有无非生长底物自我抑制的模型均能很好地模拟实验数据。然而，在较高TCE浓度（>6 mg l(-1)）时，只有考虑自我抑制的模型才能描述实验数据，这表明系统中存在TCE的自我抑制。所提出的模型还用于预测在重复间歇反应器中进行的实验数据，模型预测与实验数据之间观察到良好的一致性。结果还表明，在不存在TCE的情况下，下一个循环中TCE浓度低于2 mg l(-1)时降解过程中的生物量损失可以完全恢复，并且可以用于下一批苯酚和TCE降解的实验。然而，对于较高浓度的TCE（>6 mg l(-1)），生物量的恢复可能不如低TCE浓度时好。
