Recovery of Amoebae Community in the Root Soil of M. sativa after a Strong Contamination Pulse with n-Hexane

• Published in: Water, air, and soil pollution air, and soil pollution, 2018-09, Vol.229 (9), p.1-15, Article 293
• Main Authors: Cortés-Pérez, Sandra, Rodríguez Zaragoza, Salvador, Ferrera-Cerrato, Ronald, Luna-Pabello, Víctor Manuel
• Format: Article
• Language: English
• Subjects: Alfalfa; Analysis; Anthropogenic factors; Atmospheric Protection/Air Quality Control/Air Pollution; Bacteria; Biodegradation; Bioremediation; Chemical spills; Climate Change/Climate Change Impacts; Community structure; Contamination; Earth and Environmental Science; Environment; Environmental monitoring; Food chains; Food contamination; Food sources; Food webs; Human influences; Hydrocarbons; Hydrogeology; Low molecular weights; Microbial drug resistance; Microcosms; Microorganisms; Molecular weight; n-Hexane; Organic matter; Pollutants; Pollution; Pollution sources; Reconfiguration; Recovery; Recovery of function; Residence time; Root zone; Soil; Soil contamination; Soil pollution; Soil Science & Conservation; Soil structure; Species extinction; Species richness; Survival; Trophozoites; Water Quality/Water Pollution
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1007/s11270-018-3944-5

Microbial food webs tolerate toxic compounds depending on individualistic species resistance and their ability of using alternate food sources. Soil polluted with low-molecular weight volatile organics, such as hexane, diminishes bacterial and fungal communities despite its short residence time. Survival of microbial species depends on perturbation intensity, which in turn restricts resources for amoebae survival in polluted soil. Soil functional recovery from anthropogenic perturbations depends on microbial organic matter (OM) metabolization of pollutants. However, reconfiguration of amoebae community after soil exposure remains largely unknown. A microcosms study was carried out to determine the effects of hexane on the community structure of soil amoebae as well as the importance of Medicago sativa on amoebae community recovering. Hexane had a negative impact on species richness and structure of the amoebae community 24 h after pollution. There was a significant increase in species richness and number of amoebae 30 days after contamination. These two parameters further increased after 60 days from contamination. After 30 days of the initial trophozoites extinction caused by Hexane, M . sativa ’s . Root zone showed a significant increase of both species richness and number of individuals. This recovery trend was kept after 60 days when the highest values in species richness and abundance of individuals were shown in both polluted and non-polluted microcosms. In conclusion, M . sativa ’s root zone speeds up recovery of the amoebae community structure after pollution exposure.