Premium
Ultraviolet Radiation Induces Filamentation in Bacterial Assemblages from North Andean Patagonian Lakes
Author(s) -
Modenutti Beatriz,
Balseiro Esteban,
Corno Gianluca,
Callieri Cristiana,
Bertoni Roberto,
Caravati Emanuele
Publication year - 2010
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.2010.00758.x
Subject(s) - filamentation , actinobacteria , biology , proteobacteria , cytophaga , botany , firmicutes , bacteria , ecology , 16s ribosomal rna , flavobacterium , pseudomonas , laser , physics , optics , genetics
Through laboratory experiments, we tested whether UV radiation (UVR) induces filamentation in natural bacteria assemblages from North Andean Patagonian lakes. We incubated water from three different lakes for 72 h in four separate treatments: (1) UVR + PAR (photosynthetically active radiation), (2) 50% UVR + PAR, (3) PAR and (4) 50% PAR. The irradiance levels used in the experiments were equivalent to those registered at the epilimnion of the lakes. In the UVR treatments filamentation was induced after the first 24 h and the proportion continued to increase for the next 48–72 h. A comparison of the gross composition and diversity of the entire community (cells >0.2 μm) with bacterial filaments alone (>5.0 μm) showed that UVR‐induced filamentation is not a feature of any particular cluster. By sequencing part of the 16S rRNA gene of the taxonomic units obtained using denaturing gels, we observed that strains in the β‐Proteobacteria group were of relatively high importance in filament formation, followed by Cytophaga–Flavobacterium–Bacteroides , γ‐Proteobacteria and α‐Proteobacteria , whereas Actinobacteria were almost nonexistent in the filaments. We propose that UVR doses equivalent to those of Andean lakes produce bacterial morphological changes, and that all bacterial groups except Actinobacteria can potentially form filaments.