Lignocellulose pretreatment in a fungus-cultivating termite

Proc Natl Acad Sci U S A. 2017 May 2;114(18):4709-4714. doi: 10.1073/pnas.1618360114. Epub 2017 Apr 19.


Depolymerizing lignin, the complex phenolic polymer fortifying plant cell walls, is an essential but challenging starting point for the lignocellulosics industries. The variety of ether- and carbon-carbon interunit linkages produced via radical coupling during lignification limit chemical and biological depolymerization efficiency. In an ancient fungus-cultivating termite system, we reveal unprecedentedly rapid lignin depolymerization and degradation by combining laboratory feeding experiments, lignocellulosic compositional measurements, electron microscopy, 2D-NMR, and thermochemolysis. In a gut transit time of under 3.5 h, in young worker termites, poplar lignin sidechains are extensively cleaved and the polymer is significantly depleted, leaving a residue almost completely devoid of various condensed units that are traditionally recognized to be the most recalcitrant. Subsequently, the fungus-comb microbiome preferentially uses xylose and cleaves polysaccharides, thus facilitating final utilization of easily digestible oligosaccharides by old worker termites. This complementary symbiotic pretreatment process in the fungus-growing termite symbiosis reveals a previously unappreciated natural system for efficient lignocellulose degradation.

Keywords: NMR; age polyethism; carbohydrate; lignin; symbiosis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Fungal Proteins / metabolism*
  • Isoptera*
  • Laccase / metabolism*
  • Lignin / metabolism*
  • Termitomyces / enzymology*


  • Fungal Proteins
  • Lignin
  • Laccase