Alga-derived substrates select for distinct Betaproteobacterial lineages and contribute to niche separation in Limnohabitans strains

0366511 - BC 2012 RIV US eng J - Článek v odborném periodiku
Šimek, Karel - Kasalický, Vojtěch - Zapomělová, Eliška - Horňák, Karel
Alga-derived substrates select for distinct Betaproteobacterial lineages and contribute to niche separation in Limnohabitans strains.
Applied and Environmental Microbiology. Roč. 77, č. 20 (2011), s. 7307-7315. ISSN 0099-2240. E-ISSN 1098-5336
Grant CEP: GA ČR(CZ) GA206/08/0015; GA ČR(CZ) GAP504/10/1534; GA ČR(CZ) GA206/09/0309
Výzkumný záměr: CEZ:AV0Z60170517
Klíčová slova: Limnohabitans * R-BT065 cluster of Betaproteobacteria * algal-derived substrates * growth in axenic algal cultures * bacteria-algal interactions
Kód oboru RIV: DA - Hydrologie a limnologie
Impakt faktor: 3.829, rok: 2011

We examined the proportions of major Betaproteobacteria subgroups within bacterial communities in diverse nonaxenic, monospecific cultures of algae or cyanobacteria: four species of cryptophyta (genera Cryptomonas and Rhodomonas), four species of chlorophyta (genera Pediastrum, Staurastrum, and Chlamydomonas), and two species of cyanobacteria (genera Dolichospermum and Aphanizomenon). In the cryptophyta cultures, Betaproteobacteria represented 48 to 71% of total bacteria, the genus Limnohabitans represented 18 to 26%, and the Polynucleobacter B subcluster represented 5 to 16%. In the taxonomically diverse chlorophyta group, the genus Limnohabitans accounted for 7 to 45% of total bacteria. In contrast, cyanobacterial cultures contained significantly lower proportions of the Limnohabitans bacteria (1 to 3% of the total) than the cryptophyta and chlorophyta cultures. Notably, largely absent in all of the cultures was Polynucleobacter necessarius (Polynucleobacter C subcluster). Subsequently, we examined the growth of Limnohabitans strains in the presence of different algae or their extracellular products (EPP). Two strains, affiliated with Limnohabitans planktonicus and Limnohabitans parvus, were separately inoculated into axenic cultures of three algal species growing in an inorganic medium: Cryptomonas sp., Chlamydomonas noctigama, and Pediastrum boryanum. The Limnohabitans strains cocultured with these algae or inoculated into their EPP consistently showed (i) pronounced population growth compared to the control without the algae or EPP and (ii) stronger growth stimulation of L. planktonicus than of L. parvus. Overall, growth responses of the Limnohabitans strains cultured with algae were highly species specific, which suggests a pronounced niche separation between two closely related Limnohabitans species likely mediated by different abilities to utilize the substrates produced by different algal species.
Trvalý link: http://hdl.handle.net/11104/0201481