|Erythromycin and GC7 fail as domain-specific inhibitors for bacterial and archaeal activity in the open ocean|Frank, A.H.; Pontiller, B.; Herndl, G.; Reinthaler, T. (2016). Erythromycin and GC7 fail as domain-specific inhibitors for bacterial and archaeal activity in the open ocean
. Aquat. Microb. Ecol. 77: 99-110. dx.doi.org/10.3354/ame01792
In: Aquatic Microbial Ecology. Inter-Research: Oldendorf/Luhe. ISSN 0948-3055; e-ISSN 1616-1564, meer
N1-guanyl-1,7-diaminoheptane; Secondary production; Prokaryotes; MICROCARD-FISH; Dark ocean; Antibiotics; North Atlantic Ocean; Microautoradiography
|Auteurs|| || Top |
- Frank, A.H.
- Pontiller, B.
- Herndl, G.
- Reinthaler, T.
Domain-specific metabolic inhibitors are currently used to differentiate archaealfrom bacterial activity. However, studies testing the specificity of these inhibitors are sparse or arebased on cultured strains. We determined the inhibition specificity of erythromycin (EMY) andN1-guanyl-1,7-diaminoheptane (GC7) on bacterial and archaeal communities in the NorthAtlantic. EMY and GC7 are assumed to inhibit bacterial and archaeal activity, respectively. Heterotrophicprokaryotic activity was estimated via 3H-leucine incorporation on the cell-specificlevel using catalyzed reporter deposition fluorescence in situ hybridization combined withmicroautoradiography (MICRO-CARD-FISH). In the water masses studied, the contribution ofThaumarchaeota to total picoplankton abundance ranged from 5 to 24% while Euryarchaeotacontributed 2 to 6%; the relative abundance of Bacteria ranged from 29 to 48%. The addition ofEMY and GC7 reduced the bulk leucine incorporation by ~77% and ~41%, respectively. Evaluationof the inhibition efficiency of EMY on a cell-specific level showed no difference betweenArchaea (76.0 ± 14.2% [SD]) and Bacteria (78.2 ± 9.5%). Similarly, the reduction of substrateuptake in GC7-treated samples was similar in Archaea (59.9 ± 24%) and Bacteria (47.2 ± 9.6%).Taken together, our results suggest that in complex open-ocean prokaryotic communities neitherEMY nor GC7 is efficient as a domain-specific inhibitor.