title: High turnover rates of aerobic anoxygenic phototrophs in European freshwater lakes.
abstract: Aerobic Anoxygenic Phototrophic (AAP) bacteria are bacteriochlorophyll (BChl) a -containing organisms which use light energy to supplement their predominantly heterotrophic metabolism. Here, we investigated mortality and growth rates of AAP bacteria in three different freshwater lakes in Central Europe: the mountain lake Plešné, the oligo-mesotrophic Lake Stechlin and the forest pond Huntov. The mortality of AAP bacteria was estimated from diel changes of BChl a fluorescence. Net and gross growth rates were calculated from the increases in AAP cell numbers. The gross growth rates of AAP bacteria ranged from 0.38 to 5.6 d-1, with the highest values observed during summer months. Simultaneously, the rapidly growing AAP cells have to cope with an intense grazing pressure by both zooplankton and protists. The presented results document that during the day, gross growth usually surpased mortality. Our results indicate that AAP bacteria utilize light energy under natural conditions to maintain rapid growth rates, which are balanced by a generally intense grazing pressure.
authors.affiliation: Center Algatech, Institute of Microbiology CAS, Třeboň, 37981, Czech Republic.|Faculty of Science, University of South Bohemia, Branišovská 31, České Budějovice, 370 05, Czech Republic.
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Cepáková
authors.affiliation: Center Algatech, Institute of Microbiology CAS, Třeboň, 37981, Czech Republic.
authors.forename: Pavel
authors.initials: P
authors.lastname: Hrouzek
authors.affiliation: Center Algatech, Institute of Microbiology CAS, Třeboň, 37981, Czech Republic.
authors.forename: Eva
authors.initials: E
authors.lastname: Žišková
authors.affiliation: Center Algatech, Institute of Microbiology CAS, Třeboň, 37981, Czech Republic.
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Nuyanzina-Boldareva
authors.affiliation: Faculty of Science, University of South Bohemia, Branišovská 31, České Budějovice, 370 05, Czech Republic.
authors.forename: Michal
authors.initials: M
authors.lastname: Šorf
authors.affiliation: Biology Center CAS, Institute of Hydrobiology, Na Sádkách 702/7, České Budějovice, 370 05, Czech Republic.
authors.forename: Eliška
authors.initials: E
authors.lastname: Kozlíková-Zapomělová
authors.affiliation: Experimental Limnology, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Stechlin, 16775, Germany.
authors.forename: Ivette
authors.initials: I
authors.lastname: Salka
authors.affiliation: Experimental Limnology, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Stechlin, 16775, Germany.|Inst for Biochemistry and Biology, Potsdam University, 14469 Potsdam, Maulbeerallee 2, Germany.
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Grossart
authors.affiliation: Center Algatech, Institute of Microbiology CAS, Třeboň, 37981, Czech Republic.|Faculty of Science, University of South Bohemia, Branišovská 31, České Budějovice, 370 05, Czech Republic.
authors.forename: Michal
authors.initials: M
authors.lastname: Koblížek
mesh_terms: D000332:Aerobiosis; D001420:Bacteria, Aerobic / Q000145:classification / Q000235:genetics / Q000254:growth & development* / Q000302:isolation & purification; D044822:Biodiversity; D005060:Europe; D060106:Lakes / Q000382:microbiology*; D052817:Phototrophic Processes; D012621:Seasons