NMR studies on lignocellulose deconstructions in the digestive system of the lower termite Coptotermes formosanus Shiraki

• Tarmadi, Didi

  Research Institute for Sustainable Humanosphere (RISH), Kyoto University・Research Center for Biomaterials, Indonesian Institute of Sciences (LIPI)

• Tobimatsu, Yuki

  Research Institute for Sustainable Humanosphere (RISH), Kyoto University

• Yamamura, Masaomi

  Research Institute for Sustainable Humanosphere (RISH), Kyoto University

• Miyamoto, Takuji

  Research Institute for Sustainable Humanosphere (RISH), Kyoto University

• Miyagawa, Yasuyuki

  Research Institute for Sustainable Humanosphere (RISH), Kyoto University

• Umezawa, Toshiaki

  Research Institute for Sustainable Humanosphere (RISH), Kyoto University・Research Unit for Development and Global Sustainability, Kyoto University

• Yoshimura, Tsuyoshi

  Research Institute for Sustainable Humanosphere (RISH), Kyoto University

Abstract

Termites represent one of the most efficient lignocellulose decomposers on earth. The mechanism by which termites overcome the recalcitrant lignin barrier to gain access to embedded polysaccharides for assimilation and energy remains largely unknown. In the present study, softwood, hardwood, and grass lignocellulose diets were fed to Coptotermes formosanus workers, and structural differences between the original lignocellulose diets and the resulting feces were examined by solution-state multidimensional nuclear magnetic resonance (NMR) techniques as well as by complementary wet-chemical methods. Overall, our data support the view that lignin polymers are partially decomposed during their passage through the termite gut digestive system, although polysaccharide decomposition clearly dominates the overall lignocellulose deconstruction process and the majority of lignin polymers remain intact in the digestive residues. High-resolution NMR structural data suggested preferential removal of syringyl aromatic units in hardwood lignins, but non-acylated guaiacyl units as well as tricin end-units in grass lignins. In addition, our data suggest that termites and/or their gut symbionts may favor degradation of C–C-bonded β–5 and resinol-type β–β lignin inter-monomeric units over degradation of ether-bonded β–O–4 units, which is in contrast to what has been observed in typical lignin biodegradation undertaken by wood-decaying fungi.

Journal

• Scientific reports

  Scientific reports 8 2018-01-22

  Springer Nature

Details

• CRID: 1050845763137748352
• NII Article ID: 120006502583
• ISSN: 20452322
• HANDLE: 2433/234088
• Text Lang: en
• Article Type: journal article
• Data Source:
  • IRDB
  • CiNii Articles