17-34: Termites as a tool to improve lignocellulose biomass valorization: analysis of intermediate oligosaccharides produced by Reticulitermes santonensis

Monday, April 29, 2013
Exhibit Hall
Catherine Brasseur1, Julien Bauwens2, Cédric Tarayre3, Christel Mattéotti4, Jacqueline Destain3, Frank Delvigne5, Micheline Vandenbol4, Daniel Portetelle4, Frédéric Francis2, Eric Haubruge2, Philippe Thonart3, Jean-François Focant6 and Edwin De Pauw1, (1)Department of Chemistry/Mass Spectrometry Laboratory, University of Liège, Liège, Belgium, (2)Department of Functional and Evolutionary Entomology - Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium, (3)Department of Bio-Industries - Gembloux Agro-Bio Tech, University of Liège, Gembloux, (4)Department of Microbiology and Genomics - Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium, (5)Department of Bio-Industries - Gembloux Agro-Bio Tech, University of Liège, Gembloux, France, (6)Department of Chemistry/Organic and Biological Analytical Chemistry, University of Liège, Liège, Belgium
Termites, notorious for their voracious appetite for wood may provide key to greener fuels and chemicals from cellulosic materials. Termites employ an array of specialized microorganisms in their hind- and midguts called symbionts to break down the cell walls of plant material and catalyze the digestion process. Our purpose is to study these interaction termites-symbionts to identify efficient glucanases in order to produce them at a large scale. The methodology is based on different approaches (genomic, metabolomic, proteomic) and technologies combining specificity of the partners.

In our laboratory unit, we developed a MALDI-TOFMS method (matrix-assisted laser desorption/ionisation – time-of-flight mass spectrometry) to evaluate cellulolytic activity in termites. Intermediate hydrolysis products were analyzed to understand cellulolytic efficiency of termites and its symbionts and to evaluate their potential for enzymatic production of oligosaccharides. Reticulitermes santonensis gut extracts were incubated with carboxymethyl cellulose (CMC), crystalline celluloses or xylan substrates and hydrolysis profiles were evaluated and compared with reference profiles. Oligosaccharides with degrees of polymerization (DPs) between 3 and 12 were detected with carboxymethyl cellulose (CMC) but not with crystalline celluloses substrates. Enzymatic activity on xylan seems to be the predominant source of oligosaccharides from termites and the analysis of hydrolysis profiles showed interesting endoxylanase and glucuronidase activity. Two DP distributions were identified among the fragments detected with mean DP values of 5 and 7 for xylooligosaccharides and glucuronoxylooligosaccharides respectively. These results are of interest for industrial applications and for comprehension of the mechanisms involved.