The pH and pCO2 dependence of sulfate reduction in shallow-sea hydrothermal CO2 – venting sediments (Milos Island, Greece)
Microbial sulfate reduction is a dominant process of organic matter mineralization in sulfate-rich anoxic environments at neutral pH. Recent studies have demonstrated sulfate reduction in low pH environments, but investigations on the microbial activity at variable pH and CO2 partial pressure are st...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2013-05-01
|
| Series: | Frontiers in Microbiology |
| Subjects: | |
| Online Access: | http://journal.frontiersin.org/Journal/10.3389/fmicb.2013.00111/full |
| _version_ | 1831632645264506880 |
|---|---|
| author | Elisa eBayraktarov Elisa eBayraktarov Roy E. Price Roy E. Price Timothy G. Ferdelman Timothy G. Ferdelman Kai eFinster Kai eFinster |
| author_facet | Elisa eBayraktarov Elisa eBayraktarov Roy E. Price Roy E. Price Timothy G. Ferdelman Timothy G. Ferdelman Kai eFinster Kai eFinster |
| author_sort | Elisa eBayraktarov |
| collection | DOAJ |
| description | Microbial sulfate reduction is a dominant process of organic matter mineralization in sulfate-rich anoxic environments at neutral pH. Recent studies have demonstrated sulfate reduction in low pH environments, but investigations on the microbial activity at variable pH and CO2 partial pressure are still lacking. In this study, the effect of pH and pCO2 on microbial activity was investigated by incubation experiments with radioactive 35S targeting sulfate reduction in sediments from the shallow-sea hydrothermal vent system of Milos, Greece, where pH is naturally decreased by CO2 release. Sediments differed in their physicochemical characteristics with distance from the main site of fluid discharge. Adjacent to the vent site (T ~ 40 – 75 °C, pH ~ 5), maximal sulfate reduction rates were observed between pH 5 – 6. Sulfate reduction in hydrothermally influenced sediments decreased at neutral pH. Sediments unaffected by hydrothermal venting (T ~ 26°, pH ~ 8) expressed the highest sulfate reduction rates between pH 6 – 7. Further experiments investigating the effect of pCO2 on sulfate reduction revealed a steep decrease in activity when the partial pressure increased from 2 to 3 bar. Findings suggest that sulfate reducing microbial communities associated with hydrothermal vent system are adapted to low pH and high CO2, while communities at control sites required a higher pH for optimal activity. |
| first_indexed | 2024-12-19T05:23:31Z |
| format | Article |
| id | doaj.art-bd45487c0f564061867791ac39fc9e7c |
| institution | Directory Open Access Journal |
| issn | 1664-302X |
| language | English |
| last_indexed | 2024-12-19T05:23:31Z |
| publishDate | 2013-05-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Microbiology |
| spelling | doaj.art-bd45487c0f564061867791ac39fc9e7c2022-12-21T20:34:27ZengFrontiers Media S.A.Frontiers in Microbiology1664-302X2013-05-01410.3389/fmicb.2013.0011143510The pH and pCO2 dependence of sulfate reduction in shallow-sea hydrothermal CO2 – venting sediments (Milos Island, Greece)Elisa eBayraktarov0Elisa eBayraktarov1Roy E. Price2Roy E. Price3Timothy G. Ferdelman4Timothy G. Ferdelman5Kai eFinster6Kai eFinster7Leibniz Center for Tropical Marine EcologyMax-Planck-Institute for Marine MicrobiologyMARUM, Center for Marine Environmental SciencesUniversity of Southern CaliforniaMax-Planck-Institute for Marine MicrobiologyMARUM, Center for Marine Environmental SciencesUniversity of AarhusUniversity of AarhusMicrobial sulfate reduction is a dominant process of organic matter mineralization in sulfate-rich anoxic environments at neutral pH. Recent studies have demonstrated sulfate reduction in low pH environments, but investigations on the microbial activity at variable pH and CO2 partial pressure are still lacking. In this study, the effect of pH and pCO2 on microbial activity was investigated by incubation experiments with radioactive 35S targeting sulfate reduction in sediments from the shallow-sea hydrothermal vent system of Milos, Greece, where pH is naturally decreased by CO2 release. Sediments differed in their physicochemical characteristics with distance from the main site of fluid discharge. Adjacent to the vent site (T ~ 40 – 75 °C, pH ~ 5), maximal sulfate reduction rates were observed between pH 5 – 6. Sulfate reduction in hydrothermally influenced sediments decreased at neutral pH. Sediments unaffected by hydrothermal venting (T ~ 26°, pH ~ 8) expressed the highest sulfate reduction rates between pH 6 – 7. Further experiments investigating the effect of pCO2 on sulfate reduction revealed a steep decrease in activity when the partial pressure increased from 2 to 3 bar. Findings suggest that sulfate reducing microbial communities associated with hydrothermal vent system are adapted to low pH and high CO2, while communities at control sites required a higher pH for optimal activity.http://journal.frontiersin.org/Journal/10.3389/fmicb.2013.00111/fullsulfate reductionmicrobial activitysulfate reduction rateshallow-sea hydrothermal ventspH effectpCO2 effect |
| spellingShingle | Elisa eBayraktarov Elisa eBayraktarov Roy E. Price Roy E. Price Timothy G. Ferdelman Timothy G. Ferdelman Kai eFinster Kai eFinster The pH and pCO2 dependence of sulfate reduction in shallow-sea hydrothermal CO2 – venting sediments (Milos Island, Greece) Frontiers in Microbiology sulfate reduction microbial activity sulfate reduction rate shallow-sea hydrothermal vents pH effect pCO2 effect |
| title | The pH and pCO2 dependence of sulfate reduction in shallow-sea hydrothermal CO2 – venting sediments (Milos Island, Greece) |
| title_full | The pH and pCO2 dependence of sulfate reduction in shallow-sea hydrothermal CO2 – venting sediments (Milos Island, Greece) |
| title_fullStr | The pH and pCO2 dependence of sulfate reduction in shallow-sea hydrothermal CO2 – venting sediments (Milos Island, Greece) |
| title_full_unstemmed | The pH and pCO2 dependence of sulfate reduction in shallow-sea hydrothermal CO2 – venting sediments (Milos Island, Greece) |
| title_short | The pH and pCO2 dependence of sulfate reduction in shallow-sea hydrothermal CO2 – venting sediments (Milos Island, Greece) |
| title_sort | ph and pco2 dependence of sulfate reduction in shallow sea hydrothermal co2 venting sediments milos island greece |
| topic | sulfate reduction microbial activity sulfate reduction rate shallow-sea hydrothermal vents pH effect pCO2 effect |
| url | http://journal.frontiersin.org/Journal/10.3389/fmicb.2013.00111/full |
| work_keys_str_mv | AT elisaebayraktarov thephandpco2dependenceofsulfatereductioninshallowseahydrothermalco2ventingsedimentsmilosislandgreece AT elisaebayraktarov thephandpco2dependenceofsulfatereductioninshallowseahydrothermalco2ventingsedimentsmilosislandgreece AT royeprice thephandpco2dependenceofsulfatereductioninshallowseahydrothermalco2ventingsedimentsmilosislandgreece AT royeprice thephandpco2dependenceofsulfatereductioninshallowseahydrothermalco2ventingsedimentsmilosislandgreece AT timothygferdelman thephandpco2dependenceofsulfatereductioninshallowseahydrothermalco2ventingsedimentsmilosislandgreece AT timothygferdelman thephandpco2dependenceofsulfatereductioninshallowseahydrothermalco2ventingsedimentsmilosislandgreece AT kaiefinster thephandpco2dependenceofsulfatereductioninshallowseahydrothermalco2ventingsedimentsmilosislandgreece AT kaiefinster thephandpco2dependenceofsulfatereductioninshallowseahydrothermalco2ventingsedimentsmilosislandgreece AT elisaebayraktarov phandpco2dependenceofsulfatereductioninshallowseahydrothermalco2ventingsedimentsmilosislandgreece AT elisaebayraktarov phandpco2dependenceofsulfatereductioninshallowseahydrothermalco2ventingsedimentsmilosislandgreece AT royeprice phandpco2dependenceofsulfatereductioninshallowseahydrothermalco2ventingsedimentsmilosislandgreece AT royeprice phandpco2dependenceofsulfatereductioninshallowseahydrothermalco2ventingsedimentsmilosislandgreece AT timothygferdelman phandpco2dependenceofsulfatereductioninshallowseahydrothermalco2ventingsedimentsmilosislandgreece AT timothygferdelman phandpco2dependenceofsulfatereductioninshallowseahydrothermalco2ventingsedimentsmilosislandgreece AT kaiefinster phandpco2dependenceofsulfatereductioninshallowseahydrothermalco2ventingsedimentsmilosislandgreece AT kaiefinster phandpco2dependenceofsulfatereductioninshallowseahydrothermalco2ventingsedimentsmilosislandgreece |