@article{EigemannHiltSalkaetal.2013,
  author    = {Eigemann, Falk and Hilt, Sabine and Salka, Ivette and Grossart, Hans-Peter},
  title     = {Bacterial community composition associated with freshwater algae species specificity vs. dependency on environmental conditions and source community},
  series = {FEMS microbiology ecology},
  volume    = {83},
  journal   = {FEMS microbiology ecology},
  number    = {3},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0168-6496},
  doi       = {10.1111/1574-6941.12022},
  pages     = {650 -- 663},
  year      = {2013},
  abstract  = {We studied bacterial associations with the green alga Desmodesmus armatus and the diatom Stephanodiscus minutulus under changing environmental conditions and bacterial source communities, to evaluate whether bacteriaalgae associations are species-specific or more generalized and determined by external factors. Axenic and xenic algae were incubated in situ with and without allelopathically active macrophytes, and in the laboratory with sterile and nonsterile lake water and an allelochemical, tannic acid (TA). Bacterial community composition (BCC) of algae-associated bacteria was analyzed by denaturing gradient gel electrophoresis (DGGE), nonmetric multidimensional scaling, cluster analyses, and sequencing of DGGE bands. BCC of xenic algal cultures of both species were not significantly affected by changes in their environment or bacterial source community, except in the case of TA additions. Species-specific interactions therefore appear to overrule the effects of environmental conditions and source communities. The BCC of xenic and axenic D.armatus cultures subjected to in situ bacterial colonization, however, had lower similarities (ca.55\%), indicating that bacterial precolonization is a strong factor for bacteriaalgae associations irrespective of environmental conditions and source community. Our findings emphasize the ecological importance of species-specific bacteriaalgae associations with important repercussions for other processes, such as the remineralization of nutrients, and organic matter dynamics.},
  language  = {en}
}
@article{SvanysEigemannGrossartetal.2016,
  author    = {Svanys, Algirdas and Eigemann, Falk and Großart, Hans-Peter and Hilt, Sabine},
  title     = {Microcystins do not necessarily lower the sensitivity of Microcystis aeruginosa to tannic acid},
  series = {FEMS microbiology letters},
  volume    = {363},
  journal   = {FEMS microbiology letters},
  publisher = {Oxford Univ. Press},
  address   = {Oxford},
  issn      = {0378-1097},
  doi       = {10.1093/femsle/fnv227},
  pages     = {53 -- 77},
  year      = {2016},
  abstract  = {Different phytoplankton strains have been shown to possess varying sensitivities towards macrophyte allelochemicals, yet the reasons for this are largely unknown. To test whether microcystin (MC) is responsible for strain-specific sensitivities of Microcystis aeruginosa to macrophyte allelochemicals, we compared the sensitivity of 12 MC- and non-MC-producing M. aeruginosa strains, including an MC-deficient mutant and its wild type, to the polyphenolic allelochemical tannic acid (TA). Non-MC-producing strains showed a significantly higher sensitivity to TA than MC-producing strains, both in Chlorophyll a concentrations and quantum yields of photosystem II. In contrast, an MC-deficient mutant displayed a higher fitness against TA compared to its wild type. These results suggest that the resistance of M. aeruginosa to polyphenolic allelochemicals is not primarily related to MCs per se, but to other yet unknown protective mechanisms related to MCs.},
  language  = {en}
}
@misc{MuehlenbruchGrossartEigemannetal.2018,
  author    = {M{\"u}hlenbruch, Marco and Grossart, Hans-Peter and Eigemann, Falk and Voss, Maren},
  title     = {Mini-review: Phytoplankton-derived polysaccharides in the marine environment and their interactions with heterotrophic bacteria},
  series = {Environmental microbiology},
  volume    = {20},
  journal   = {Environmental microbiology},
  number    = {8},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {1462-2912},
  doi       = {10.1111/1462-2920.14302},
  pages     = {2671 -- 2685},
  year      = {2018},
  abstract  = {Within the wealth of molecules constituting marine dissolved organic matter, carbohydrates make up the largest coherent and quantifiable fraction. Their main sources are from primary producers, which release large amounts of photosynthetic products - mainly polysaccharides - directly into the surrounding water via passive and active exudation. The organic carbon and other nutrients derived from these photosynthates enrich the 'phycosphere' and attract heterotrophic bacteria. The rapid uptake and remineralization of dissolved free monosaccharides by heterotrophic bacteria account for the barely detectable levels of these compounds. By contrast, dissolved combined polysaccharides can reach high concentrations, especially during phytoplankton blooms. Polysaccharides are too large to be taken up directly by heterotrophic bacteria, instead requiring hydrolytic cleavage to smaller oligo- or monomers by bacteria with a suitable set of exoenzymes. The release of diverse polysaccharides by various phytoplankton taxa is generally interpreted as the deposition of excess organic material. However, these molecules likely also fulfil distinct, yet not fully understood functions, as inferred from their active modulation in terms of quality and quantity when phytoplankton becomes nutrient limited or is exposed to heterotrophic bacteria. This minireview summarizes current knowledge regarding the exudation and composition of phytoplankton-derived exopolysaccharides and acquisition of these compounds by heterotrophic bacteria.},
  language  = {en}
}