Relation between nutritional mode and ecophysiological niche width and its effect on distribution pattern and habitat specificity of chrysomonad flagellates
Hydrogeology, Hydrology, Limnology, Urban Water Management, Water Chemistry, Integrated Water Resources Management
Microbial Ecology and Applied Microbiology
Final Report Abstract
Chrysophyceae are a diverse group of planktonic protists widely distributed in freshwater. They encompass a variety of orders, whereby heterotrophy has evolved independently in several phylogenetic lineages. Therefore, closely related taxa evolved that developed different feeding strategies (photo-, mixo-, heterotrophy). In the present project, we have investigated the niche width of chrysophytes both in laboratory experiments and using environmental data of 217 freshwater lakes throughout Europe. In laboratory experiments, some patterns can be identified in relation to niche width. Heterotrophic Chrysophyceae could tolerate higher salinities, as well as more acidic and alkaline pH values compared to phototrophic Chrysophyceae. Whereas phototrophic strains, or mixotrophic strains with predomninate phototrophic nutrition react strongly to changes in light intensity. But the laboratory experiments also showed that the niche width is strongly strain-specific. For instance, experiments showed that mixotrophic strains of Ochromonas danica and Poterioochromonas malhamensis exhibited great tolerances to all conditions tested. We have investigated the extent to which the potential niche differs from the niche actually exploited using molecular data from over 200 European freshwater lakes. Our studies confirmed that the Chrysophyceae are one of the most common and widespread groups in freshwater lakes. Ochromonadales and Chrysosaccales are the most widespread Chrysophyceae groups and show a high degree of OTU diversity. Most detected and assignable OTUs were affiliated with mixotrophic Chrysophyceae. Ecophysiological tolerance range differed neither systematically with phylogeny nor with nutritional mode. However, taxa with an exceptionally high tolerance range are found among the different clades and nutrition modes and belong to the most abundant and widespread eukaryotes in freshwater ecosystems.
Publications
- (2018) Evolution of heterotrophy in chrysophytes as reflected by comparative transcriptomics. FEMS Microbiol Ecol 94
Graupner N, Jensen M, Bock C, Marks S, Rahmann S, Beisser D, Boenigk J
(See online at https://doi.org/10.1093/femsec/fiy039) - (2018) Genome size of chrysophytes varies with cell size and nutritional mode. Organisms Div Evol 18:163-173
Olefeld JL, Majda S, Albach DC, Marks S, Boenigk J
(See online at https://doi.org/10.1007/s13127-018-0365-7) - (2018) Geographic distance and mountain ranges structure freshwater protist communities on a European scale. Metabarcoding and Metagenomics 2: e21519
Boenigk J, Wodniok S, Bock C, Beisser D, Hempel C, Grossmann L, Lange A, Jensen M
(See online at https://doi.org/10.3897/mbmg.2.21519) - (2018) Synchrony of Eukaryotic and Prokaryotic Planktonic Communities in Three Seasonally Sampled Austrian Lakes. Frontiers Microbiol 9:1290
Bock C, Salcher M, Jensen M, Pandey RV, Boenigk J
(See online at https://doi.org/10.3389/fmicb.2018.01290) - (2019) Intraspecific variation in protists: clues for microevolution from Poteriospumella lacustris (Chrysophyceae). Genome Biol Evol 11: 2492–2504
Majda S, Boenigk J, Beisser D
(See online at https://doi.org/10.1093/gbe/evz171) - (2020) Centers of endemism of freshwater protists deviate from pattern of taxon richness on a continental scale. Scientific Rep 10:14431
Olefeld JL, Bock C, Jensen M, Vogt JC, Sieber G, Albach D, Boenigk J
(See online at https://doi.org/10.1038/s41598-020-71332-z) - (2020) Factors shaping community patterns of protists and bacteria on a European scale. Environ Microbiol 22:2243-2260
Bock C, Jensen M, Forster D, Marks S, Nuy J, Psenner R, Beisser D, Boenigk J
(See online at https://doi.org/10.1111/1462-2920.14992)
