Líffræðifélag Íslands
Líffræðiráðstefnan 2015
Erindi/veggspjald / Talk/poster V88
Bryndís Björnsdóttir (1), Justyna M. Dobruchowska (2), Ólafur H. Friðjónsson (1), Johannis P. Kamerling (2), Josef Altenbuchner (3), Hilde Watzlawick (3) and Guðmundur Ó. Hreggviðsson (1,4)
1. Matís, 2. Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 3. Institute for Industrial Genetics, University of Stuttgart, Germany, 4. Faculty of Life and Environmental Sciences, University of Iceland
Kynnir / Presenter: Bryndís Björnsdóttir
Tengiliður / Corresponding author: Bryndís Björnsdóttir (bryndis@matis.is)
Alginate lyases catalyse β-elimination of the 4-O glycosidic bonds in alginate, an important industrial macroalgal polysaccharide comprised of guluronate and mannuronate blocks. Substantial interest has been in the discovery and characteristics of alginate lyases in recent years, focusing on their potential use in industry and research. Of particular interest is their application in macroalgal-based biorefineries, where robust enzymes are required for degradation of alginate, the most abundant carbohydrate in many seaweeds. Four predicted alginate lyase encoding genes from Rhodothermus marinus str. 378 were cloned and recombinantly expressed in E. coli. The enzymes were purified and characterized. All four enzymes, termed AlyRm1 to 4, were active thermostable alginate lyases with distinct characteristics in terms of optimum temperature and pH, exo- and endo- activities, and preferences towards degradation of guluronate and mannuronate blocks. Near complete degradation of alginate into unsaturated mono-uronates by simultaneous incubation with AlyRm3 and AlyRm4 was achieved. Therefore, it is possible to apply these enzymes separately for selective partial degradation of alginate, or in combination for production of mono-uronates. This is the first report of characterized thermostable alginate lyases and a patent application has been filed. Their application in industrial processes, where higher processing temperatures are required or preferred, is of substantial interest.