Bacterial diversity of a wooded riparian strip soil specifically designed for enhancing the denitrification process
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This research is part of a project aimed at verifying the potential of a specifically assessed wooded riparian zone in removing the excess of combined nitrogen from the Zero River so as to reduce nutrient inputs into the Venice Lagoon. Among the specific objectives of the project, there was the determination of change in the composition of the microbial populations of soil of the wooded riparian strip. The composition of the bacterial communities collected at different depths inside and outside the riparian strip was determined by combined approaches involving cultivation (CFU), microscopic approaches (CTC test), and DNA-based techniques (ARDRA and DGGE). The size of the living population was the same inside and outside the experimental strip, with a minor percentage of culturable bacteria. Higher numbers of metabolically active bacteria and higher bacterial diversity were detected in the internal soil, with deeper soil layers showing reduced diversity, thus indicating that soil management within the riparian strip effectively supports the viability of bacterial communities. Total operational taxonomic units (OTUs) and percentage of single OTUs were also found to be always higher in the internal soil samples for all soil layers, with the percentage of Firmicutes increasing and Actinobacteria decreasing with depth. The increasing soil organic carbon inputs due to the contribution of the growing plants were found to support bacterial diversity in all soil layers. DNA-based analysis also indicated a clear effect of the applied treatments on soil bacterial diversity and a well-defined separation of the bacterial communities related to the different soil layers of the riparian strip.
KeywordsPhytoremediation Riparian wooded strip Denitrification Soil microbial population dynamic Soil microbial communities DGGE
This work was supported by Consorzio Acque Risorgive and Veneto Region. Md. M. R. was a recipient of a Ph.D. fellowship of the University of Padua.
- APHA, AWWA, WEF (2005) Standard methods for the examination of water and wastewater, 21st edn. American Public Health Association, Washington, DCGoogle Scholar
- Bothe H, Ferguson SJ, Newton WE (2006) Biology of the nitrogen cycle. Elsevier, AmsterdamGoogle Scholar
- Boz B, MdM R, Bottegal M, Basaglia M, Squartini A, Gumiero B, Casella S (2013) Vegetation, soil and hydrology management influence denitrification activity and the composition of nirK-type denitrifier communities in a newly afforested riparian buffer. N Biotechnol. doi:10.1016/j.nbt.2013.03.009 PubMedGoogle Scholar
- Navarro-Noya YE, Jan-Roblero J, González-Chávez MC, Hernández-Gama R, Hernández-Rodríguez C (2010) Bacterial communities associated with the rhizosphere of pioneer plants (Bahia xylopoda and Viguiera linearis) growing on heavy metals-contaminated soils. Antonie van Leeuwenhoek 97:335–349PubMedCrossRefGoogle Scholar
- Shannon CE, Weaver W (1963) The mathematical theory of communication. University of Illinois Press, UrbanaGoogle Scholar
- Spruill TB (2004) Effectiveness of riparian buffers in controlling ground-water discharge of nitrate to streams in selected hydrogeologic settings of the North Carolina Coastal Plain. Water Sci Techol 49:63–70Google Scholar
- Tilak KVBR, Ranganayaki N, Pal KK, De R, Saxena AK, Nautiyal CS, Mittal S, Tripathi AK, Johri BN (2005) Diversity of plant growth and soil health supporting bacteria. Curr Sci 89:136–150Google Scholar
- USDA-SCS (US Department of Agriculture, Soil Conservation Service) (1984) User’s guide for the CREAMS computer model—Washington Computer Center version. USDA-SCS TR-72, Washington, DCGoogle Scholar