Naslov
Bacterial-phytoplankton interface in natural lake ecosystems

Autori
Žutinić, Petar ; Orlić, Sandi ; Pjevac, Petra ; Plenković-Moraj, Anđelka ; Kralj Borojević, Koraljka ; Ljubešić, Zrinka ; Bosak, Sunčica ; Šimunović, Maja ; Stanković, Igor ; Stević, Filip ; Špoljarić Maronić, Dubravka ; Žuna Pfeiffer, Tanja ; Goreta, Gordana ; Borics, Gábor ; Várbíró, Gábor ; Vucić, Anita ; Ternjej, Ivančica ; Gligora Udovič, Marija

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
18th workshop of the International Association for Phytoplankton Taxonomy and Ecology (IAP) : abstracts book / - Natal, 2017, 8-8

Skup
18th workshop of the International Association for Phytoplankton Taxonomy and Ecology (IAP)

Mjesto i datum
Natal, Brazil, 27.08.2017. - 03.09.2017

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Bacterial community ; phytoplankton ; interface ; mixotrophy ; lakes

Sažetak
Cryptophytes, chrysophytes and dinoflagellates are groups of phytoplankton largely consisting of species with well documented mixotrophy. These groups also comprise a major part of phytoplankton biomass in karstic lakes with good to high ecological status. The aim of the study was to establish the link between bacterial community and potential mixotrophs in the planktonic community of a karstic mesotrophic Visovac Lake (Krka National Park, Croatia), in order to provide a precise assessment of the ecological status of lake ecosystem. Integrated vertical samples for phytoplankton, samples for physical-chemical parameters, water chemistry analyses and bacteriology were taken simultaneously from the deepest point of the lake, once a month in the period between April and September 2016. Phytoplankton composition and biomass were determined by standard methods, while fluorescence in situ hybridization with signal amplification and catalyzed reporter deposition (CARD-FISH) was applied for bacterial microscopic quantification. Additionally, filtered water was used for DNA extraction and 16S rRNA gene sequencing for bacterial identification. Total phytoplankton biomass varied from 0.24 mgL-1 (June) to 0.75 mgL-1 (July). Potentially mixotrophic species characterizing the community were: Dinobryon divergens, Dinobryon bavaricum, Dinobryon crenulatum, Chromulina sp., Ochromonas danica, Plagioselmis nannoplanctica, Cryptomonas sp., Parvodinium inconspicuum and Ceratium hirundinella. The lowest total bacterial abundance was determined in April (2.61 x 106 cell mL-1), whilst the highest was in July (11.39 x 106 cell mL-1). Sequencing of 6 integrated samples resulted in a total of 132 429 nucleotide sequences, with 5 bacterial groups identified: Betaproteobacteria, Actinobacteria, Bacterioidetes, Chloroflexi and Veruccomicrobia. Actinobacteria was the most abundant class in all investigated months (avg. 34%), while Betaproteobacteria was subdominant (avg. 22%). Multivariate analysis provided a statistically significant corelation between the selected phytoplankton species and determined bacterial groups. The results will be used to determine relation between mixotrophic species and bacterial groups in lakes with variable ecological status.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

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