A tripartite model system for Southern Ocean diatom-bacterial interactions reveals the coexistence of competing symbiotic strategies
Abstract Southern Ocean (SO) diatoms play an important role in global carbon flux, and their influence on carbon export is directly linked to interactions with epiphytic bacteria. Bacterial symbionts that increase diatom growth promote atmospheric carbon uptake, while bacterial degraders divert diat...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Oxford University Press
2022-10-01
|
| Series: | ISME Communications |
| Online Access: | https://doi.org/10.1038/s43705-022-00181-w |
| _version_ | 1797226823910686720 |
|---|---|
| author | Sarah Andrew Travis Wilson Stephanie Smith Adrian Marchetti Alecia N. Septer |
| author_facet | Sarah Andrew Travis Wilson Stephanie Smith Adrian Marchetti Alecia N. Septer |
| author_sort | Sarah Andrew |
| collection | DOAJ |
| description | Abstract Southern Ocean (SO) diatoms play an important role in global carbon flux, and their influence on carbon export is directly linked to interactions with epiphytic bacteria. Bacterial symbionts that increase diatom growth promote atmospheric carbon uptake, while bacterial degraders divert diatom biomass into the microbial loop where it can then be released as carbon dioxide through respiration. To further explore SO diatom-bacterial associations, a natural model system is needed that is representative of these diverse and important interactions. Here, we use concurrent cultivation to isolate a species of the ecologically-important SO diatom, Pseudo-nitzschia subcurvata, and its co-occurring bacteria. Although vitamin-depleted, axenic Pseudo-nitzschia grew poorly in culture, addition of a co-isolated Roseobacter promoted diatom growth, while addition of a co-isolated Flavobacterium negatively impacted diatom growth. Microscopy revealed both bacterial isolates are physically associated with diatom cells and genome sequencing identified important predicted functions including vitamin synthesis, motility, cell attachment mechanisms, and diverse antimicrobial weapons that could be used for interbacterial competition. These findings revealed the natural coexistence of competing symbiotic strategies of diatom-associated bacteria in the SO, and the utility of this tripartite system, composed of a diatom and two bacterial strains, as a co-culture model to probe ecological-relevant interactions between diatoms and the bacteria that compete for access to the phycosphere. |
| first_indexed | 2024-04-24T14:31:02Z |
| format | Article |
| id | doaj.art-5208ec2672cd473cba9fbee444addead |
| institution | Directory Open Access Journal |
| issn | 2730-6151 |
| language | English |
| last_indexed | 2024-04-24T14:31:02Z |
| publishDate | 2022-10-01 |
| publisher | Oxford University Press |
| record_format | Article |
| series | ISME Communications |
| spelling | doaj.art-5208ec2672cd473cba9fbee444addead2024-04-03T02:07:19ZengOxford University PressISME Communications2730-61512022-10-012111210.1038/s43705-022-00181-wA tripartite model system for Southern Ocean diatom-bacterial interactions reveals the coexistence of competing symbiotic strategiesSarah Andrew0Travis Wilson1Stephanie Smith2Adrian Marchetti3Alecia N. Septer4Department of Earth, Marine & Environmental Sciences, University of North CarolinaEnvironment, Ecology & Energy Program, University of North CarolinaDepartment of Earth, Marine & Environmental Sciences, University of North CarolinaDepartment of Earth, Marine & Environmental Sciences, University of North CarolinaDepartment of Earth, Marine & Environmental Sciences, University of North CarolinaAbstract Southern Ocean (SO) diatoms play an important role in global carbon flux, and their influence on carbon export is directly linked to interactions with epiphytic bacteria. Bacterial symbionts that increase diatom growth promote atmospheric carbon uptake, while bacterial degraders divert diatom biomass into the microbial loop where it can then be released as carbon dioxide through respiration. To further explore SO diatom-bacterial associations, a natural model system is needed that is representative of these diverse and important interactions. Here, we use concurrent cultivation to isolate a species of the ecologically-important SO diatom, Pseudo-nitzschia subcurvata, and its co-occurring bacteria. Although vitamin-depleted, axenic Pseudo-nitzschia grew poorly in culture, addition of a co-isolated Roseobacter promoted diatom growth, while addition of a co-isolated Flavobacterium negatively impacted diatom growth. Microscopy revealed both bacterial isolates are physically associated with diatom cells and genome sequencing identified important predicted functions including vitamin synthesis, motility, cell attachment mechanisms, and diverse antimicrobial weapons that could be used for interbacterial competition. These findings revealed the natural coexistence of competing symbiotic strategies of diatom-associated bacteria in the SO, and the utility of this tripartite system, composed of a diatom and two bacterial strains, as a co-culture model to probe ecological-relevant interactions between diatoms and the bacteria that compete for access to the phycosphere.https://doi.org/10.1038/s43705-022-00181-w |
| spellingShingle | Sarah Andrew Travis Wilson Stephanie Smith Adrian Marchetti Alecia N. Septer A tripartite model system for Southern Ocean diatom-bacterial interactions reveals the coexistence of competing symbiotic strategies ISME Communications |
| title | A tripartite model system for Southern Ocean diatom-bacterial interactions reveals the coexistence of competing symbiotic strategies |
| title_full | A tripartite model system for Southern Ocean diatom-bacterial interactions reveals the coexistence of competing symbiotic strategies |
| title_fullStr | A tripartite model system for Southern Ocean diatom-bacterial interactions reveals the coexistence of competing symbiotic strategies |
| title_full_unstemmed | A tripartite model system for Southern Ocean diatom-bacterial interactions reveals the coexistence of competing symbiotic strategies |
| title_short | A tripartite model system for Southern Ocean diatom-bacterial interactions reveals the coexistence of competing symbiotic strategies |
| title_sort | tripartite model system for southern ocean diatom bacterial interactions reveals the coexistence of competing symbiotic strategies |
| url | https://doi.org/10.1038/s43705-022-00181-w |
| work_keys_str_mv | AT sarahandrew atripartitemodelsystemforsouthernoceandiatombacterialinteractionsrevealsthecoexistenceofcompetingsymbioticstrategies AT traviswilson atripartitemodelsystemforsouthernoceandiatombacterialinteractionsrevealsthecoexistenceofcompetingsymbioticstrategies AT stephaniesmith atripartitemodelsystemforsouthernoceandiatombacterialinteractionsrevealsthecoexistenceofcompetingsymbioticstrategies AT adrianmarchetti atripartitemodelsystemforsouthernoceandiatombacterialinteractionsrevealsthecoexistenceofcompetingsymbioticstrategies AT aleciansepter atripartitemodelsystemforsouthernoceandiatombacterialinteractionsrevealsthecoexistenceofcompetingsymbioticstrategies AT sarahandrew tripartitemodelsystemforsouthernoceandiatombacterialinteractionsrevealsthecoexistenceofcompetingsymbioticstrategies AT traviswilson tripartitemodelsystemforsouthernoceandiatombacterialinteractionsrevealsthecoexistenceofcompetingsymbioticstrategies AT stephaniesmith tripartitemodelsystemforsouthernoceandiatombacterialinteractionsrevealsthecoexistenceofcompetingsymbioticstrategies AT adrianmarchetti tripartitemodelsystemforsouthernoceandiatombacterialinteractionsrevealsthecoexistenceofcompetingsymbioticstrategies AT aleciansepter tripartitemodelsystemforsouthernoceandiatombacterialinteractionsrevealsthecoexistenceofcompetingsymbioticstrategies |