Proteomic response of three marine ammonia-oxidizing archaea to hydrogen peroxide and their metabolic interactions with a heterotrophic alphaproteobacterium
Bayer, B.; Pelikan, C.; Bittner, M.J.; Reinthaler, T.; Könneke, M.; Herndl, G.; Offre, P. (2019). Proteomic response of three marine ammonia-oxidizing archaea to hydrogen peroxide and their metabolic interactions with a heterotrophic alphaproteobacterium. mSystems 4(4): e00181-19. https://dx.doi.org/10.1128/msystems.00181-19Additional data: In: mSystems. American Society for Microbiology: Washington, DC. e-ISSN 2379-5077, more |   |
| Keyword | Nitrosopumilus Könneke, Bernhard, de la Torre, Walker, Waterbury & Stahl, 2005 [WoRMS]
| | Author keywords | Nitrosopumilus; ammonia-oxidizing archaea; hydrogen peroxide; metabolic interactions; oxidative stress; proteomics |
| Authors | | Top | - Bayer, B.
- Pelikan, C.
- Bittner, M.J.
- Reinthaler, T.
| - Könneke, M.
- Herndl, G., more
- Offre, P., more
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| Abstract | Ammonia-oxidizing archaea (AOA) play an important role in the nitrogen cycle and account for a considerable fraction of the prokaryotic plankton in the ocean. Most AOA lack the hydrogen peroxide (H2O2)-detoxifying enzyme catalase, and some AOA have been shown to grow poorly under conditions of exposure to H2O2. However, differences in the degrees of H2O2 sensitivity of different AOA strains, the physiological status of AOA cells exposed to H2O2, and their molecular response to H2O2 remain poorly characterized. Further, AOA might rely on heterotrophic bacteria to detoxify H2O2, and yet the extent and variety of costs and benefits involved in these interactions remain unclear. Here, we used a proteomics approach to compare the protein profiles of three Nitrosopumilus strains grown in the presence and absence of catalase and in coculture with the heterotrophic alphaproteobacterium Oceanicaulis alexandrii. We observed that most proteins detected at a higher relative abundance in H2O2-exposed Nitrosopumilus cells had no known function in oxidative stress defense. Instead, these proteins were putatively involved in the remodeling of the extracellular matrix, which we hypothesize to be a strategy limiting the influx of H2O2 into the cells. Using RNA-stable isotope probing, we confirmed that O. alexandrii cells growing in coculture with the Nitrosopumilus strains assimilated Nitrosopumilus-derived organic carbon, suggesting that AOA could recruit H2O2-detoxifying bacteria through the release of labile organic matter. Our results contribute new insights into the response of AOA to H2O2 and highlight the potential ecological importance of their interactions with heterotrophic free-living bacteria in marine environments. |
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