Abstract


LIGHT REGIME IMPACTS METATRANSCRIPTOMIC PROFILES IN MULTIPLE TROPHIC LEVELS OF A STREAM BIOFILM COMMUNITY

Phototrophic stream biofilms are highly complex featuring algae, protists and bacteria. It has previously been difficult to study these communities in their entirety using microscopy or PCR-based molecular techniques. We studied community dynamics and function in natural stream biofilms using metatranscriptomics targeting ribosomal RNA and mRNA of all three domains of life. Biofilms were grown under conditions ranging from full light to 95% light exclusion in an Austrian pre-alpine stream, hypothesising that shading would shift the community from an algal-dominated state to a more detritus fueled community. The light regime had moderate impacts on the algal community yet had remarkable cascading effects on the ciliate and bacterial communities. For example, bacterial grazing ciliates appear to be more abundant with shading whereas omnivorous taxa decline. Surprisingly, transcripts related to photosynthesis increased in the low light treatment, indicating functional adaptations of the algae. This study shows that metatranscriptomic techniques are a powerful way to analyze complex biofilm communities. It gives important insights into the regulation of community structure and function through bottom-up controls such as light regime and top-down regulation through grazing.

Authors

Bengtsson, M. M., University of Vienna, Austria, mia.bengtsson@univie.ac.at

Wagner, K., University of Vienna, Austria, karoline.wagner@univie.ac.at

Burns, N. R., University of Vienna, Austria

Schwab, C., ETH Zürich, Switzerland, clarissa.schwab@hest.ethz.ch

Urich, T., University of Vienna, Austria, tim.urich@univie.ac.at

Battin, T. J., University of Vienna, Austria, tom.battin@univie.ac.at

Details

Oral presentation

Session #:040
Date: 2/25/2015
Time: 17:45
Location: Seminario 6-7 (Floor 1)

Presentation is given by student: No