Pubblicazione scientifica

Autotrophic carbon fixation strategies used by nitrifying prokaryotes in freshwater lakes

FILONE TECNOLOGICO	TEMA
trasformazione e commercializzazione

RIASSUNTO

ABSTRACT

Niche specialization of nitrifying prokaryotes is usually studied with tools targeting molecules involved in the oxidation of ammonia and nitrite. The ecological significance of diverse CO2 fixation strategies used by nitrifiers is, however, mostly unexplored. By analyzing autotrophy-related genes in combination with amoA marker genes based on droplet digitial PCR and CARD-FISH counts targeting rRNA, we quantified the distribution of nitrifiers in eight stratified lakes. Ammonia oxidizing (AO) Thaumarchaeota using the 3-hydroxypropionate/4-hydroxybutyrate pathway dominated deep and oligotrophic lakes, whereas Nitrosomonas-related taxa employing the Calvin cycle were important AO bacteria in smaller lakes. The occurrence of nitrite oxidizing Nitrospira, assimilating CO2 with the reductive TCA cycle, was strongly correlated with the distribution of Thaumarchaeota. Recently discovered complete ammonia-oxidizing bacteria (comammox) belonging to Nitrospira accounted only for a very small fraction of ammonia oxidizers (AOs) present at the study sites. Altogether, this study gives a first insight on how physicochemical characteristics in lakes are associated to the distribution of nitrifying prokaryotes with different CO2 fixation strategies. Our investigations also evaluate the suitability of functional genes associated with individual CO2 assimilation pathways to study niche preferences of different guilds of nitrifying microorganisms based on an autotrophic perspective.

DATA

Data di pubblicazione: 18/08/2018

AUTORI

ALFREIDER ALBIN
GRIMUS VICTORIA
LUGER MARTIN
EKBLAD ANJA
SALCHER MICHAELA M
SUMMERER MONIKA

ENTE DI AFFERENZA

INST ECOLOGY UNIV INNSBRUCK TECHNIKERSTRA E 25 6020 INNSBRUCK AUSTRIA
INST WATER ECOLOGY FISHERIES BIOLOGY & LAKE RSCH FEDERAL AGENCY FOR WATER MGMT SCHARFLING 18 5310 MONDSEE AUSTRIA
INSTITUTE OF HYDROBIOLOGY BIOLOGY CENTRE CAS NA SADKACH 702/7370 05 CESKE BUDEJOVICE CZECH REPUBLIC

RIVISTA

FEMS Microbiology Ecology, 94(10), fiy163

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