TY  - JOUR
A1  - Salka, Ivette
A1  - Wurzbacher, Christian
A1  - Garcia, Sarahi L.
A1  - Labrenz, Matthias
A1  - Juergens, Klaus
A1  - Grossart, Hans-Peter
T1  - Distribution of acI-Actinorhodopsin genes in Baltic Sea salinity gradients indicates adaptation of facultative freshwater photoheterotrophs to brackish waters
JF  - Environmental microbiology
Y1  - 2014
SN  - 1462-2912
SN  - 1462-2920
VL  - 16
IS  - 2
SP  - 586
EP  - 597
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Wurzbacher, Christian
A1  - Roesel, Stefan
A1  - Rychla, Anna
A1  - Grossart, Hans-Peter
T1  - Importance of saprotrophic freshwater fungi for pollen degradation
JF  - PLoS one
N2  - Fungi and bacteria are the major organic matter (OM) decomposers in aquatic ecosystems. While bacteria are regarded as primary mineralizers in the pelagic zone of lakes and oceans, fungi dominate OM decomposition in streams and wetlands. Recent findings indicate that fungal communities are also active in lakes, but little is known about their diversity and interactions with bacteria. Therefore, the decomposer niche overlap of saprotrophic fungi and bacteria was studied on pollen (as a seasonally recurring source of fine particulate OM) by performing microcosm experiments with three different lake types. Special emphasis was placed on analysis of fungal community composition and diversity. We hypothesized that (I) pollen select for small saprotrophic fungi and at the same time for typical particle-associated bacteria; (II) fungal communities form specific free-living and attached sub-communities in each lake type; (III) the ratio between fungi or bacteria on pollen is controlled by the lake's chemistry. Bacteria-to-fungi ratios were determined by quantitative PCR (qPCR), and bacterial and fungal diversity were studied by clone libraries and denaturing gradient gel electrophoresis (DGGE) fingerprints. A protease assay was used to identify functional differences between treatments. For generalization, systematic differences in bacteria-to-fungi ratios were analyzed with a dataset from the nearby Baltic Sea rivers. High abundances of Chytridiomycota as well as occurrences of Cryptomycota and yeast-like fungi confirm the decomposer niche overlap of saprotrophic fungi and bacteria on pollen. As hypothesized, microbial communities consistently differed between the lake types and exhibited functional differences. Bacteria-to-fungi ratios correlated well with parameters such as organic carbon and pH. The importance of dissolved organic carbon and nitrogen for bacteria-to-fungi ratios was supported by the Baltic Sea river dataset. Our findings highlight the fact that carbon-to-nitrogen ratios may also control fungal contributions to OM decomposition in aquatic ecosystems.
Y1  - 2014
U6  - https://doi.org/10.1371/journal.pone.0094643
SN  - 1932-6203
VL  - 9
IS  - 4
PB  - PLoS
CY  - San Fransisco
ER  -