title: Metabolomic profiling of 13C-labelled cellulose digestion in a lower termite: insights into gut symbiont function.
abstract: Termites consume an estimated 3-7 billion tonnes of lignocellulose annually, a role in nature which is unique for a single order of invertebrates. Their food is digested with the help of microbial symbionts, a relationship that has been recognized for 200 years and actively researched for at least a century. Although DNA- and RNA-based approaches have greatly refined the details of the process and the identities of the participants, the allocation of roles in space and time remains unclear. To resolve this issue, a pioneer study is reported using metabolomics to chart the in situ catabolism of (13)C-cellulose fed to the dampwood species Hodotermopsis sjostedti. The results confirm that the secretion of endogenous cellulases by the host may be significant to the digestive process and indicate that a major contribution by hindgut bacteria is phosphorolysis of cellodextrins or cellobiose. This study provides evidence that essential amino acid acquisition by termites occurs following the lysis of microbial tissue obtained via proctodaeal trophallaxis.
authors.affiliation: Tropical Biosphere Research Center, COMB, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan.
authors.forename: Gaku
authors.initials: G
authors.lastname: Tokuda
authors.affiliation: RIKEN Center for Sustainable Resource Science, Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan.
authors.forename: Yuuri
authors.initials: Y
authors.lastname: Tsuboi
authors.affiliation: RIKEN Antibiotics Laboratory, Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan Department of Biological Sciences, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Meguro, Tokyo 152-8550, Japan.
authors.forename: Kumiko
authors.initials: K
authors.lastname: Kihara
authors.affiliation: Tropical Biosphere Research Center, COMB, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan.
authors.forename: Seikou
authors.initials: S
authors.lastname: Saitou
authors.affiliation: RIKEN Antibiotics Laboratory, Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan Graduate School of Medical Life Science, Yokohama City University, Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan.
authors.forename: Sigeharu
authors.initials: S
authors.lastname: Moriya
authors.affiliation: School of Biological Science, The University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: Nathan
authors.initials: N
authors.lastname: Lo
authors.affiliation: RIKEN Center for Sustainable Resource Science, Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan Graduate School of Medical Life Science, Yokohama City University, Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Nagoya 464-8601, Japan jun.kikuchi@riken.jp.
authors.forename: Jun
authors.initials: J
authors.lastname: Kikuchi
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D002247:Carbon Isotopes; D002482:Cellulose / Q000378:metabolism*; D041981:Gastrointestinal Tract / Q000378:metabolism* / Q000382:microbiology; D007413:Intestinal Mucosa / Q000378:metabolism; D020049:Isoptera / Q000378:metabolism / Q000382:microbiology / Q000502:physiology*; D009682:Magnetic Resonance Spectroscopy; D055442:Metabolome; D013559:Symbiosis
chemical_list: D000596:Amino Acids; D002247:Carbon Isotopes; D002482:Cellulose
keywords: cellulose digestion; metabolomics; nuclear magnetic resonance; termite