Enzyme additions as a tool to assess the potential bioavailability of organically bound nutrients
Enzyme additions as a tool to assess the potential bioavailability of organically bound nutrients
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DOI：
10.1016/j.soilbio.2008.03.001
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发表时间：
2008-09-01
影响因子：
9.7
通讯作者：
Buenemann, E. K.
中科院分区：
文献类型：
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作者：
Buenemann, E. K.
通过添加过量的合适底物并随后测定产品释放来测量土壤和水样中的潜在酶活性。如果该方法相反并添加过量的酶，则底物可用性将受到速率限制，并且产物的最大释放表明样品中给定底物的可用性。该方法已用于一系列研究，将磷酸酶添加到土壤、粪便和沉积物提取物、土壤悬浮液以及湖泊和海水中 (n = 41)。使用碳、氮和硫循环酶的研究要少得多 (n = 14)。在这篇综述中，使用来自磷循环的酶的研究中的例子讨论了酶添加的方法学方面。对各种土壤提取物和水样进行的荟萃分析显示，大多数研究（第 75 个百分位）表明酶水解的有机磷利用率高达 60%，粗植酸酶制剂显示出最低的底物特异性和最大的磷释放量。与添加磷循环中的酶相比，通过将碳、氮和硫循环中的酶添加到土壤悬浮液和土壤有机质提取物中，通常可以实现较低的底物降解。酶添加可以成为工艺研究中的一个有价值的工具，只要包括所有必要的控制并优化测定条件以确保反应完成。提出了制定标准协议的建议。 (C) 2008 Elsevier Ltd. 保留所有权利。
Potential enzyme activities in soil and water samples are measured by addition of an excess amount of suitable substrate and subsequent determination of product release. If the approach is reversed and an excess of enzyme is added, substrate availability becomes rate-limiting and the maximum release of product indicates the availability of a given substrate in a sample. This approach has been used in a range of studies using phosphatase enzyme additions to soil, manure and sediment extracts, soil suspensions, and lake and sea water (n = 41). Significantly fewer studies have used enzymes from the carbon, nitrogen and sulfur cycles (n = 14). In this review, the methodological aspects of enzyme additions are discussed using examples from studies in which enzymes from the phosphorus cycle were used. A meta-analysis performed for various soil extracts and water samples revealed that the majority of studies (75th percentile) indicate availability of organic phosphorus to enzymatic hydrolysis of up to 60%, with crude phytase preparations showing the lowest substrate specificity and greatest release of phosphorus. Compared to addition of enzymes from the phosphorus cycle, lower substrate degradation was generally achieved by addition of enzymes from the carbon, nitrogen and sulfur cycles to soil suspensions and soil organic matter extracts. Enzyme additions can be a valuable tool in process research, provided all the necessary controls are included and assay conditions optimized to ensure that the reaction reaches completion. Recommendations for the development of a standard protocol are made. (C) 2008 Elsevier Ltd. All rights reserved.