Oligotyping reveals divergent responses of predation resistant bacteria to aquatic productivity and plankton composition
(English)Manuscript (preprint) (Other academic)
Predation-resistance has been suggested to be a key for persistence of pathogenic bacteria in aquatic environments. Little is known about driving factors for different types of protozoa resistant bacteria (PRB). We studied if presence of PRB is linked to specific plankton taxa, the aquatic nutrient state, or predation pressure on bacteria. Nineteen freshwater systems were sampled and analyzed for PRB, plankton composition and physicochemical variables. Three PRB genera were identified; Pseudomonas, Mycobacterium and Rickettsia. Use of minimum entropy decomposition algorithm and phylogenetic analysis showed that different nodes (representing OTUs of high taxonomic resolution) matched to environmental isolates of the three genera. Links between the PRB genera and specific plankton taxa were found, but showed different relationships depending on if 18S rRNA OTU or microscopy data were used in the analysis. Mycobacterium spp. was negatively correlated to aquatic nutrient state, while Pseudomonas showed the opposite pattern. Rickettsia spp. was positively related to predation pressure on bacteria. Both Mycobacterium and Rickettsia were more abundant in systems with high eukaryotic diversity, while Pseudomonas occurred abundantly in waters with low prokaryotic diversity. The different drivers may be explained by varying ecological strategies, where Mycobacterium and Rickettsia are slow growing and have an intracellular life style, while Pseudomonas is fast growing and opportunistic. Here we give an insight to the possibilities of newly advanced methods such as sequencing and oligotyping to link potential pathogens with biomarkers. This as a tool to assist predictions of the occurrence and persistence of environmental pathogens.
Protozoa resistant bacteria (PRB), trophic state, oligotyping, predation pressure, biomarker
IdentifiersURN: urn:nbn:se:umu:diva-133333OAI: oai:DiVA.org:umu-133333DiVA: diva2:1087100
FunderEcosystem dynamics in the Baltic Sea in a changing climate perspective - ECOCHANGESwedish Research Council for Environment, Agricultural Sciences and Spatial Planning, 17-2008-1443
Medfinansiärer var även: Swedish Ministry of Foreign Affairs, project A4952, the Swedish Civil Contingencies Agency, project B4055 and the Swedish Ministry of Defence, project A4040 and A4042.2017-04-052017-04-052017-04-06