Interspecific competition and protistan grazing affect the coexistence of freshwater betaproteobacterial strains
Language English Country Great Britain, England Media print-electronic
Document type Journal Article, Research Support, Non-U.S. Gov't
PubMed
26656063
DOI
10.1093/femsec/fiv156
PII: fiv156
Knihovny.cz E-resources
- Keywords
- Betaproteobacteria, chemostat, co-cultivation, flagellate-selective bacterivory, interspecific competition, synergistic cooperation,
- MeSH
- Comamonadaceae growth & development isolation & purification MeSH
- Coculture Techniques MeSH
- Oxalobacteraceae growth & development isolation & purification MeSH
- Food Chain * MeSH
- Fresh Water microbiology MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The competitive strength of four cosmopolitan freshwater betaproteobacterial isolates was investigated in the presence or absence of bacterivorous flagellates during continuous cultivation in artificial minimal medium at two dilution rates. Bacteria reached similar abundance and growth rate in monocultures, but in co-cultures, two strains (Acidovorax sp. and Massilia sp.) displayed significantly higher numbers and growth rates. These potential cross-feeding benefits were also supported by a high nutritional versatility of the two strains. In contrast, Hydrogenophaga sp. was seemingly less competitive or even inhibited by co-cultivation, and Limnohabitans planktonicus displayed striking abundance fluctuations. The latter two strains were least versatile in the uptake of different carbon sources and thus suffered more from interspecific competition. Moreover, remarkable strain-specific responses appeared when bacteria experienced increasing loss rates due to grazing and/or raised dilution rates. Limnohabitans planktonicus developed no successful defence strategy and was close to extinction. Massilia sp. formed grazing-resistant filaments exclusively at low dilution, but was highly reduced at increased flow-through. Acidovorax sp. was selectively ingested, but compensated grazing losses with accelerated growth rates and formed (co-)aggregates together with Hydrogenophaga sp. to escape predation at high flow-through. These species-specific interactions, growth responses and defence strategies strongly modulate mixed microbial assemblages and the microbial food web.
Biology Centre CAS Institute of Hydrobiology České Budějovice Czech Republic
Limnological Station University of Zurich Kilchberg Switzerland
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