Novel thermostable glycosidases in the extracellular matrix of the terrestrial cyanobacterium Nostoc commune

• Mohamed Morsy Fatthy

  <I>Division of Life Science, Graduate School of Natural Science and Technology, Kanazawa University</I>

• Kuzuha Satomi

  <I>Department of Biology, Faculty of Science, Kanazawa University</I>

• Takani Yayoi

  <I>Division of Biological Science, Graduate School of Natural Science and Technology, Kanazawa University</I>

• Sakamoto Toshio

  <I>Division of Life Science, Graduate School of Natural Science and Technology, Kanazawa University</I> <I>Department of Biology, Faculty of Science, Kanazawa University</I> <I>Division of Biological Science, Graduate School of Natural Science and Technology, Kanazawa University</I>

Abstract

The cyanobacterium Nostoc commune is adapted to the terrestrial environment and forms a visible colony in which the cells are embedded in extracellular polysaccharides (EPSs), which play a crucial role in the extreme desiccation tolerance of this organism. When natural colonies were immersed in water, degradation of the colonies occurred within 2 days and N. commune cells were released into the water. The activities that hydrolyze glycoside bonds in various N. commune fractions were examined using artificial nitrophenyl-linked sugars as substrates. A β-D-glucosidase purified from the water-soluble fraction was resistant to 20 min of boiling. The β-D-glucosidase, with a molecular mass of 20 kDa, was identified as a cyanobacterial fasciclin protein based on its N-terminal amino-acid sequence. The 36-kDa major protein in the water-soluble fraction was purified, and the N-terminal amino-acid sequence of the protein was found to be identical to that of the water-stress protein (WspA) of N. commune. This WspA protein also showed heat-resistant β-D-galactosidase activity. The fasciclin protein and WspA in the extracellular matrix may play a role in the hydrolysis of the EPSs surrounding the cells, possibly as an aid in the dispersal of cells, thus expanding the colonies of this cyanobacterium.

Journal

• The Journal of General and Applied Microbiology

  The Journal of General and Applied Microbiology 54 (5), 243-252, 2008

  Applied Microbiology, Molecular and Cellular Biosciences Research Foundation

Keywords

• desiccation tolerance
• extracellular polysaccharide
• fasciclin
• WspA

Details

• CRID: 1390001204145627264
• NII Article ID: 130004802109
• NII Book ID: AA00698664
• DOI: 10.2323/jgam.54.243
• COI: 1:CAS:528:DC%2BD1cXhtlyqtrrM
• ISSN: 13498037
• ISSN: 00221260
• Web Site: http://hdl.handle.net/2297/36907
• Web Site: http://www.jstage.jst.go.jp/article/jgam/54/5/54_5_243/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • IRDB
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed