Archaeal biofilms: Composition of extracellular polymeric substances, exopolysaccharide synthesis and secretion in Sulfolobus acidocaldarius
- 1Molecular Enzyme Technology and Biochemistry (MEB), Environmental Microbiology and Biotechnology, University of Duisburg-Essen, 45141 Essen, Germany
- 2Applied Analytical Chemistry (AAC), University of Duisburg-Essen, 45141 Essen, Germany
- 3Molecular Biology of Archaea, Institute for Biology II, Albert-Ludwigs-University Freiburg, 79104 Freiburg, Germany
- 4Aquatic Microbiology, Environmental Microbiology and Biotechnology, University of Duisburg-Essen, 45141 Essen, Germany
Archaea, representatives of the third domain of life, are often referred to as “extremophiles” since most of the cultivable species are adapted to extreme environments [1]. However, environmental cultivation-independent approaches (metagenomics) revealed a wide distribution of Archaea in moderate habitats suggesting a major role in geochemical processes. Similar to Bacteria, also Archaea are believed to exist predominantly in the biofilm mode, but knowledge about archaeal biofilm formation and structure, extracellular polymeric substance (EPS) composition and synthesis is scarce [2].
Sulfolobus acidocaldarius is a thermoacidophilic, aerobic Crenarchaeon (78°C and pH 2-3) that was isolated from acid hot springs [3]. The organism is easy to cultivate under laboratory conditions and a genetic system is established. In this study, we investigate S. acidocaldarius biofilms with a special focus on synthesis and transport of exopolysaccharides (PS). PS constitute a major EPS component beside proteins and eDNA, suggesting an important role in Sulfolobus biofilms, and changes in PS composition were observed in response to environmental stress [4]. A gene cluster encoding several glycosyltransferases (GTs) as well as membrane proteins (MPs), likely involved in exopolysaccharide synthesis, was identified in S. acidocaldarius. Several deletion mutants have been constructed lacking certain GT and MP encoding genes from the PS gene cluster. A combination of methods including the quantification of biofilm formation, isolation and quantification of EPS components, visualization of biofilm and PS structures via confocal laser scanning microscopy as well as molecular and biochemical techniques have been applied to compare biofilm characteristics of wildtype and mutant strains. First insight into the function of GTs and MPs will be presented and a model of PS synthesis and export will be proposed.
[1] Schocke et al. (2019). Curr. Opin. in Biotechnol. 59, 71-77.
[2] van Wolferen et al. (2018). Nature Rev. Microbiol. 16(11), 699-713.
[3] Brock et al. (1972). Arch. Mikrobiol. 84, 54-68.
[4] Jachlewski et al. (2015). Front. Bioeng. Biotechnol. 3, 123.
How to cite: Kuschmierz, L., Meyer, M., Meyer, B., Albers, S.-V., Bräsen, C., Wingender, J., Schmitz, O. J., and Siebers, B.: Archaeal biofilms: Composition of extracellular polymeric substances, exopolysaccharide synthesis and secretion in Sulfolobus acidocaldarius, biofilms 9 conference, Karlsruhe, Germany, 29 September–1 Oct 2020, biofilms9-59, https://doi.org/10.5194/biofilms9-59, 2020
