Biodegradability continuum and biodegradation kinetics of natural organic matter described by the beta distribution
Biodegradability continuum and biodegradation kinetics of natural organic matter described by the beta distribution
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DOI：
10.1007/s10533-010-9419-4
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发表时间：
2010-03
期刊：
影响因子：
4
通讯作者：
A. Vähätalo;H. Aarnos;S. Mäntyniemi
中科院分区：
文献类型：
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作者：
A. Vähätalo;H. Aarnos;S. Mäntyniemi
我们遵循一个长期（长达503天）的微生物矿化溶解有机碳（DOC）从湖水中的生物测定和描述的动力学与一个新的模型的基础上的反应连续的方法生物降解。DOC的可生物降解性表示为生物降解的概率，假设其遵循β分布。我们比较了我们的beta模型的性能，五个早期的模型：最简单的一阶动力学模型，两个G模型，功率模型和伽马模型。最简单的一级动力学模型不能很好地描述DOC的微生物矿化作用（r2= 0.73），而其它模型能很好地解释DOC的生物降解动力学（r2> 0.95）。当我们通过减少数据量来评估超出生物测定长度的模型的外推能力时，G模型的预测能力很差。相反，β模型预测的生物降解动力学一致和正确的基础上，即使只有三个观察的时间。贝塔模型还提供了长期预测（长达5,000年），沿着观察到的沉积物中有机碳的长期矿化轨迹。此外，β模型制定的DOC的生物降解性连续体，这是偏向于低生物降解性。在生物测定过程中，随着DOC中最可生物降解的部分被消耗，向低生物降解性的倾斜增加。Beta模型定量描述了生物降解连续体，可以以现实的方式预测生物降解，从而提高我们对生物降解性和天然有机物在环境中的作用的理解。
We followed a long-term (up to 503 days) microbial mineralization of dissolved organic carbon (DOC) from lake water in a bioassay and described the kinetics of biodegradation with a new model based on a reactivity continuum approach. The biodegradability of DOC was expressed as the probability of biodegradation, which was assumed to follow a beta distribution. We compared the performance of our beta model to five earlier models: the simplest first order kinetic model, two G models, the power model and the gamma model. The simplest first order kinetic model described the decreasing microbial mineralization of DOC poorly (r2= 0.73), but the other models explained the observed kinetics of biodegradation well (r2> 0.95). When we assessed the extrapolation power of models beyond the length of the bioassay by reducing the amount of data, the predictive power of the G models was poor. Instead, the beta model predicted the biodegradation kinetics consistently and correctly based on even only three observations in time. The beta model provided also long-term predictions (up to 5,000 years) along the observed long-term mineralization trajectory of organic carbon in sediments. Additionally, the beta model formulated the biodegradability continuum of DOC, which was skewed towards low biodegradability. During the bioassay, the skew towards low biodegradability increased as the most biodegradable parts of DOC were consumed. The beta model describes the biodegradability continuum quantitatively and can predict biodegradation in a realistic manner, thus, improving our understanding about the biodegradability and the role of natural organic matter in the environment.