Geobacter Dominates the Inner Layers of a Stratified Biofilm on a Fluidized Anode During Brewery Wastewater Treatment
In this study, we designed a microbial electrochemical fluidized bed reactor (ME-FBR), with an electroconductive anodic bed made of activated carbon particles for treating a brewery wastewater. Under a batch operating mode, acetate and propionate consumption rates were 13-fold and 2.4-fold higher, r...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2018-03-01
|
| Series: | Frontiers in Microbiology |
| Subjects: | |
| Online Access: | http://journal.frontiersin.org/article/10.3389/fmicb.2018.00378/full |
| _version_ | 1818548613080416256 |
|---|---|
| author | Sara Tejedor-Sanz Sara Tejedor-Sanz Patricia Fernández-Labrador Patricia Fernández-Labrador Steven Hart Cesar I. Torres Cesar I. Torres Abraham Esteve-Núñez Abraham Esteve-Núñez |
| author_facet | Sara Tejedor-Sanz Sara Tejedor-Sanz Patricia Fernández-Labrador Patricia Fernández-Labrador Steven Hart Cesar I. Torres Cesar I. Torres Abraham Esteve-Núñez Abraham Esteve-Núñez |
| author_sort | Sara Tejedor-Sanz |
| collection | DOAJ |
| description | In this study, we designed a microbial electrochemical fluidized bed reactor (ME-FBR), with an electroconductive anodic bed made of activated carbon particles for treating a brewery wastewater. Under a batch operating mode, acetate and propionate consumption rates were 13-fold and 2.4-fold higher, respectively, when the fluidized anode was polarized (0.2 V) with respect to open circuit conditions. Operating in a continuous mode, this system could effectively treat the brewery effluent at organic loading rates (OLR) over 1.7 kg m-3NRV d-1 and with removal efficiencies of 95 ± 1.4% (hydraulic retention time of 1 day and an influent of 1.7 g-COD L-1). The coulombic efficiency values highly depended upon the OLR applied, and varied from a 56 ± 15% to 10 ± 1%. Fluorescence in situ hybridization (FISH) analysis revealed a relative high abundance of Geobacter species (ca. 20%), and clearly showed a natural microbial stratification. Interestingly, the Geobacter cluster was highly enriched in the innermost layers of the biofilm (thickness of 10 μm), which were in contact with the electroconductive particles of bed, whereas the rest of bacteria were located in the outermost layers. To our knowledge, this is the first time that such a clear microbial stratification has been observed on an anode-respiring biofilm. Our results revealed the relevant role of Geobacter in switching between the electrode and other microbial communities performing metabolic reactions in the outermost environment of the biofilm. |
| first_indexed | 2024-12-12T08:22:27Z |
| format | Article |
| id | doaj.art-e3cf40de8feb416e9aecc665c181bac9 |
| institution | Directory Open Access Journal |
| issn | 1664-302X |
| language | English |
| last_indexed | 2024-12-12T08:22:27Z |
| publishDate | 2018-03-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Microbiology |
| spelling | doaj.art-e3cf40de8feb416e9aecc665c181bac92022-12-22T00:31:22ZengFrontiers Media S.A.Frontiers in Microbiology1664-302X2018-03-01910.3389/fmicb.2018.00378335002Geobacter Dominates the Inner Layers of a Stratified Biofilm on a Fluidized Anode During Brewery Wastewater TreatmentSara Tejedor-Sanz0Sara Tejedor-Sanz1Patricia Fernández-Labrador2Patricia Fernández-Labrador3Steven Hart4Cesar I. Torres5Cesar I. Torres6Abraham Esteve-Núñez7Abraham Esteve-Núñez8Department of Chemical Engineering, University of Alcalá, Alcalá de Henares, SpainIMDEA Water Institute, Alcalá de Henares, SpainDepartment of Chemical Engineering, University of Alcalá, Alcalá de Henares, SpainMahou San Miguel, Madrid, SpainBiodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe, AZ, United StatesBiodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe, AZ, United StatesSchool for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, United StatesDepartment of Chemical Engineering, University of Alcalá, Alcalá de Henares, SpainIMDEA Water Institute, Alcalá de Henares, SpainIn this study, we designed a microbial electrochemical fluidized bed reactor (ME-FBR), with an electroconductive anodic bed made of activated carbon particles for treating a brewery wastewater. Under a batch operating mode, acetate and propionate consumption rates were 13-fold and 2.4-fold higher, respectively, when the fluidized anode was polarized (0.2 V) with respect to open circuit conditions. Operating in a continuous mode, this system could effectively treat the brewery effluent at organic loading rates (OLR) over 1.7 kg m-3NRV d-1 and with removal efficiencies of 95 ± 1.4% (hydraulic retention time of 1 day and an influent of 1.7 g-COD L-1). The coulombic efficiency values highly depended upon the OLR applied, and varied from a 56 ± 15% to 10 ± 1%. Fluorescence in situ hybridization (FISH) analysis revealed a relative high abundance of Geobacter species (ca. 20%), and clearly showed a natural microbial stratification. Interestingly, the Geobacter cluster was highly enriched in the innermost layers of the biofilm (thickness of 10 μm), which were in contact with the electroconductive particles of bed, whereas the rest of bacteria were located in the outermost layers. To our knowledge, this is the first time that such a clear microbial stratification has been observed on an anode-respiring biofilm. Our results revealed the relevant role of Geobacter in switching between the electrode and other microbial communities performing metabolic reactions in the outermost environment of the biofilm.http://journal.frontiersin.org/article/10.3389/fmicb.2018.00378/fullGeobacterfluidized bedbioelectrochemistrymicrobial stratificationwastewater treatmentmicrobial electron transport |
| spellingShingle | Sara Tejedor-Sanz Sara Tejedor-Sanz Patricia Fernández-Labrador Patricia Fernández-Labrador Steven Hart Cesar I. Torres Cesar I. Torres Abraham Esteve-Núñez Abraham Esteve-Núñez Geobacter Dominates the Inner Layers of a Stratified Biofilm on a Fluidized Anode During Brewery Wastewater Treatment Frontiers in Microbiology Geobacter fluidized bed bioelectrochemistry microbial stratification wastewater treatment microbial electron transport |
| title | Geobacter Dominates the Inner Layers of a Stratified Biofilm on a Fluidized Anode During Brewery Wastewater Treatment |
| title_full | Geobacter Dominates the Inner Layers of a Stratified Biofilm on a Fluidized Anode During Brewery Wastewater Treatment |
| title_fullStr | Geobacter Dominates the Inner Layers of a Stratified Biofilm on a Fluidized Anode During Brewery Wastewater Treatment |
| title_full_unstemmed | Geobacter Dominates the Inner Layers of a Stratified Biofilm on a Fluidized Anode During Brewery Wastewater Treatment |
| title_short | Geobacter Dominates the Inner Layers of a Stratified Biofilm on a Fluidized Anode During Brewery Wastewater Treatment |
| title_sort | geobacter dominates the inner layers of a stratified biofilm on a fluidized anode during brewery wastewater treatment |
| topic | Geobacter fluidized bed bioelectrochemistry microbial stratification wastewater treatment microbial electron transport |
| url | http://journal.frontiersin.org/article/10.3389/fmicb.2018.00378/full |
| work_keys_str_mv | AT saratejedorsanz geobacterdominatestheinnerlayersofastratifiedbiofilmonafluidizedanodeduringbrewerywastewatertreatment AT saratejedorsanz geobacterdominatestheinnerlayersofastratifiedbiofilmonafluidizedanodeduringbrewerywastewatertreatment AT patriciafernandezlabrador geobacterdominatestheinnerlayersofastratifiedbiofilmonafluidizedanodeduringbrewerywastewatertreatment AT patriciafernandezlabrador geobacterdominatestheinnerlayersofastratifiedbiofilmonafluidizedanodeduringbrewerywastewatertreatment AT stevenhart geobacterdominatestheinnerlayersofastratifiedbiofilmonafluidizedanodeduringbrewerywastewatertreatment AT cesaritorres geobacterdominatestheinnerlayersofastratifiedbiofilmonafluidizedanodeduringbrewerywastewatertreatment AT cesaritorres geobacterdominatestheinnerlayersofastratifiedbiofilmonafluidizedanodeduringbrewerywastewatertreatment AT abrahamestevenunez geobacterdominatestheinnerlayersofastratifiedbiofilmonafluidizedanodeduringbrewerywastewatertreatment AT abrahamestevenunez geobacterdominatestheinnerlayersofastratifiedbiofilmonafluidizedanodeduringbrewerywastewatertreatment |