| Title | The VIOLA Project: Functional responses of groundwater microbial community across the salinity gradient in a coastal karst aquifer |
| Abstract | The vulnerability to salinization is a major issue for coastal aquifers. The resulting rapid
modifications of hydro-geochemical characteristics, driven by the different origin of water inputs,
can modify the properties of the resident biological communities. The study of structural and
functional properties of groundwater microbial community, posed at the base of the heterotrophic
food web, assumes an increasing importance to describe the effect of water quality on C-cycling
and the resilience of groundwater systems to changes.
Within the framework of the VIOLA project, this study was entailed to explore the groundwater
quality and the functional responses of the microbial community across the gradient of salinity in
a coastal karst aquifer located in Apulia Region (Southern Italy). The investigated area (1227 km2) is
located in a semi-arid climate region with predominantly agricultural vocation. In this area, an
excess of withdrawals for irrigation and other uses, often results in a significant decline of the
water table, facilitating saline intrusion.
The main physical-chemical parameters of 47 groundwater sampling sites (T, pH, oxidationreduction
potential, electrical conductivity, major anions/cations, trace elements, dissolved
oxygen, ammonia, nitrites, cyanides and dissolved organic carbon) were measured, along with
microbial community analyses including the total cell abundance, the High Nucleic Acid and Low
Nucleic Acid content cell ratio (Flow Cytometry), the total coliform and Escherichia Coli
contamination (Colilert-18 assay), the microbial metabolic potential (Biolog EcoPlates), and the
microbial respiration (Biolog MT2 MicroPlates). The preliminary results allowed identifying two
major groups of waters with different salinity levels and concentrations of Cl, Na, Mg and SO4.
Prokaryotic cell abundance (mean 3.5 x 104 ± 4.6 x 104 cells/ml) showed higher values in saline
waters, so as HNA cell percentages and total coliforms. Saline waters were also characterised by
relatively higher metabolic potential and respiration values. In conclusion, the observed
groundwater quality changes induced the stimulation of the functional microbial properties and
the functional diversity. These changes in the metabolic potential of the resident communities
could alter the ability to exploit the available resources and modify the related groundwater
biogeochemical cycling.metabolic adaptation to a condition of high salinization level. |
| Source | EUROPEAN GEOSCIENCES UNION (EGU) GENERAL ASSEMBLY 2020, VIENNA, 3-8/5/2020 |
| Keywords | MICROBIAL COMMUNITYCOASTAL AQUIFERHYDROGEOCHEMISTRYFUNCTIONAL CHARACTERISTICS |
| Year | 2020 |
| Type | Contributo in atti di convegno |
| Authors | Melita M. , Amalfitano S. , Frollini E., Ghergo S., Masciale R., Parrone D., Passarella G., Preziosi E., Vurro M., Zoppini A. |
| Text | 449746 2020 MICROBIAL COMMUNITY COASTAL AQUIFER HYDROGEOCHEMISTRY FUNCTIONAL CHARACTERISTICS The VIOLA Project Functional responses of groundwater microbial community across the salinity gradient in a coastal karst aquifer Melita M. , Amalfitano S. , Frollini E., Ghergo S., Masciale R., Parrone D., Passarella G., Preziosi E., Vurro M., Zoppini A. IRSA CNR The vulnerability to salinization is a major issue for coastal aquifers. The resulting rapid modifications of hydro geochemical characteristics, driven by the different origin of water inputs, can modify the properties of the resident biological communities. The study of structural and functional properties of groundwater microbial community, posed at the base of the heterotrophic food web, assumes an increasing importance to describe the effect of water quality on C cycling and the resilience of groundwater systems to changes. Within the framework of the VIOLA project, this study was entailed to explore the groundwater quality and the functional responses of the microbial community across the gradient of salinity in a coastal karst aquifer located in Apulia Region Southern Italy . The investigated area 1227 km2 is located in a semi arid climate region with predominantly agricultural vocation. In this area, an excess of withdrawals for irrigation and other uses, often results in a significant decline of the water table, facilitating saline intrusion. The main physical chemical parameters of 47 groundwater sampling sites T, pH, oxidationreduction potential, electrical conductivity, major anions/cations, trace elements, dissolved oxygen, ammonia, nitrites, cyanides and dissolved organic carbon were measured, along with microbial community analyses including the total cell abundance, the High Nucleic Acid and Low Nucleic Acid content cell ratio Flow Cytometry , the total coliform and Escherichia Coli contamination Colilert 18 assay , the microbial metabolic potential Biolog EcoPlates , and the microbial respiration Biolog MT2 MicroPlates . The preliminary results allowed identifying two major groups of waters with different salinity levels and concentrations of Cl, Na, Mg and SO4. Prokaryotic cell abundance mean 3.5 x 104 ± 4.6 x 104 cells/ml showed higher values in saline waters, so as HNA cell percentages and total coliforms. Saline waters were also characterised by relatively higher metabolic potential and respiration values. In conclusion, the observed groundwater quality changes induced the stimulation of the functional microbial properties and the functional diversity. These changes in the metabolic potential of the resident communities could alter the ability to exploit the available resources and modify the related groundwater biogeochemical cycling.metabolic adaptation to a condition of high salinization level. Published version https //doi.org/10.5194/egusphere egu2020 7630 LA PRESENTAZIONE HA RIGURDATO I RISULTATI OTTENUTI DALLA SPERIMENTAZIONE CONDOTTA NELL AMBITO DEL PROGETTO P.O. FESR VIOLA EUROPEAN GEOSCIENCES UNION EGU GENERAL ASSEMBLY 2020 VIENNA 3 8/5/2020 Internazionale Contributo The VIOLA Project Functionalresponsesofgroundwatermicrobialcommunityacrossthesalinitygradientinacoastalkarstaquifer REPRINT DELL ABSTRACT Melita et al_EGU2020.pdf Contributo in atti di convegno danieleparrone PARRONE DANIELE eleonorafrollini FROLLINI ELEONORA marcomelita MELITA MARCO michele.vurro VURRO MICHELE stefano.ghergo GHERGO STEFANO giuseppe.passarella PASSARELLA GIUSEPPE elisabetta.preziosi PREZIOSI ELISABETTA stefano.amalfitano AMALFITANO STEFANO rita.masciale MASCIALE RITA annamaria.zoppini ZOPPINI ANNAMARIA TA.P04.032.002 Ruolo delle comunita microbiche nei cicli biogeochimici e nella degradazione degli inquinanti DTA.AD002.026.001 GESTIONE SOSTENIBILE DEGLI ECOSISTEMI ACQUATICI E RISPOSTA AGLI IMPATTI DI ORIGINE NATURALE ED ANTROPICA MONTEROTONDO BRUGHERIO BARI |
