Líffræðifélag Íslands
Líffræðiráðstefnan 2015
Erindi/veggspjald / Talk/poster V94
Heiða B. Friðjónsdóttir (1), Oddur Vilhelmsson (1,2)
1. University of Akureyri, 2. Biomedical Center, University of Iceland.
Kynnir / Presenter: Heiða B. Friðjónsdóttir
Tengiliður / Corresponding author: Heiða B. Friðjónsdóttir (ha060161@unak.is)
BIOPROSPECTING PSYCHROTROPHIC SPHINGOMONADS FOR HYDROCARBON DEGRADATION Heiða B. Friðjónsdóttir1 and Oddur Vilhelmsson1,2 Department of Natural Resource Sciences, University of Akureyri, Borgir v. Nordurslod, 600 Akureyri, Iceland1, Biomedical Center, University of Iceland, Vatnsmýrarvegur 16, 101 Reykjavik, Iceland2 Sphingomonads are aerobic, heterotrophic Alphaproteobacteria characterized by the presence of glycosphingolipids in their outer cell membranes and the absence of lipopolysaccharides. Sphingomonads from cold environments are potentially of great value as cold-active bioremediators and may also be of interest for several industrial applications due to their relative ease of culturing and their rather wide spectrum of utilizable carbon sources, with many species being capable of degrading compounds normally considered recalcitrant to biotic degradation. We therefore sampled several cold habitats, including glacial meltwater, glacial moraines, tundra soils, arid soils, riverbeds, various lichens, and more, and isolated sphingomonads. Thirty-nine sphingomonad isolates were investigated in terms of their ability to degrade petrochemicals such as naphthalene and hexane. Samples (water, soil, lichens) were collected aseptically in various locations in northern and central Iceland. Isolates were identified by sequencing of partial 16S rRNA gene amplicons using standard methods. Thirty-nine sphingomonad isolates were screened for naphthalene oxidation via a chromogenic fast-blue-mediated detection of naphthol. Degradation of biopolymers was tested on plates supplemented with azo cross-linked substrates. Biosurfactant production was tested by a simple drop-collapse assay. Ten selected strains were whole genome-sequenced by Illumina MiSeq sequencing of Nextera XT-prepared libraries. Assembly and BLAST-based annotation was performed using the CLC Genomic Workbench. Thirty-nine isolates were assigned by partial 16S rDNA sequencing to the family Sphingomonadaceae. Several of these are considered likely to comprise novel species, based on their relatively low level of similarity to their closest relative in GenBank. Several of the strains tested positive for hydrocarbon degradation at low temperatures and/or display other cold-active oxidative or biodegradative capabilities, such as glycanase and esterase activities. Production of biosurfactants was also observed for several strains. Preliminary screening of the as-yet unannotated genome sequencing data indicates the presence of several oxygenase genes and other genes thought important for petrochemical degradation. Spingomonads from cold environments in northern and central Iceland hold promise as efficient, easily cultured and manipulated, cold-active bioremediators of petrochemicals. REFERENCES: Sigurbjörnsdóttir, M. A., Heiðmarsson, S., Jónsdóttir, A. R., Vilhelmsson, O. (2014): Novel bacteria associated with Arctic seashore lichens have potential roles in nutrient scavenging. Can. J. Microbiol. 60, 307-317. doi: 10.1139/cjm-2013-0888. Jóelsson, J. P., Friðjónsdóttir, H., and Vilhelmsson, O. (2013) Bioprospecting a glacial river in Iceland for bacterial biopolymer degraders. Cold Regions Sci. Technol. 96, 86-95. doi: 10.1016/j.coldregions.2013.03.001.