Department Agronomy Food Natural Resources Animals and Environment (DAFNAE), Università di Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro (PD), Italy.
N Biotechnol. 2013 Sep 25;30(6):675-84. doi: 10.1016/j.nbt.2013.03.009. Epub 2013 Apr 6.
Soil microbial community composition and activity could be affected by suitable manipulation of the environment they live in. If correctly applied such an approach could become a very effective way to remediate excess of chemicals. The concentration of nitrogen, especially nitrate deriving from agricultural managements, is generally found to increase in water flow. Therefore, by forcing the water flow through a buffer strip specifically designed and possibly afforested with suitable plant species, may result effective in reducing high nitrogen contents. The management of a riparian buffer may definitely affect the soil microbial activities, including denitrification, as well as the composition of the community. The present study reports on the changes occurred in terms of denitrifying microbial community composition, as compared to that of a neighbouring agricultural area, as a consequence of hydraulic management coupled to the suspension of farming practices and to the development of the woody and herbaceous vegetation. With this aim, denitrification was repeatedly measured and the data obtained were related to those deriving from a specific analysis of bacterial groups involved in denitrification. nirK, encoding for nitrite reductase, an enzyme essential for the conversion of nitrite to nitric oxide and considered the key step in the denitrification process, was chosen as the target gene. The main results obtained indicated that denitrification activity changes in riparian buffer as compared to agricultural soil and it is strongly influenced by carbon availability and soil depth. Although no significant differences on the community composition between superficial (0-15 cm) and medium (40-55 cm) layers were observed, the nirK-type denitrifier community was shown to significantly differ between riparian and agricultural soils in both surface and medium layers.
土壤微生物群落组成和活性可能会受到其生存环境的适当操纵的影响。如果正确应用，这种方法可能成为修复化学物质过剩的非常有效的方法。氮的浓度，特别是来自农业管理的硝酸盐，通常会在水流中增加。因此，通过迫使水流通过专门设计的缓冲区，并可能用合适的植物物种造林，可能会有效地减少高氮含量。河岸缓冲带的管理肯定会影响土壤微生物活性，包括反硝化作用，以及群落的组成。本研究报告了由于水力管理与停止耕作和发展木本和草本植被相结合，与邻近农业区相比，反硝化微生物群落组成发生的变化。为此，反复测量了反硝化作用，并将获得的数据与参与反硝化作用的细菌群的特定分析所获得的数据相关联。nirK 编码亚硝酸盐还原酶，是将亚硝酸盐转化为一氧化氮所必需的酶，被认为是反硝化过程的关键步骤，被选为靶基因。主要结果表明，与农业土壤相比，河岸缓冲带的反硝化活性发生了变化，并且受碳可用性和土壤深度的强烈影响。尽管在表层（0-15cm）和中层（40-55cm）之间未观察到群落组成的显著差异，但nirK 型反硝化菌群落的组成在表层和中层均明显不同于河岸带和农业土壤。
