title: Metagenomic and functional analysis of hindgut microbiota of a wood-feeding higher termite.
abstract: From the standpoints of both basic research and biotechnology, there is considerable interest in reaching a clearer understanding of the diversity of biological mechanisms employed during lignocellulose degradation. Globally, termites are an extremely successful group of wood-degrading organisms and are therefore important both for their roles in carbon turnover in the environment and as potential sources of biochemical catalysts for efforts aimed at converting wood into biofuels. Only recently have data supported any direct role for the symbiotic bacteria in the gut of the termite in cellulose and xylan hydrolysis. Here we use a metagenomic analysis of the bacterial community resident in the hindgut paunch of a wood-feeding 'higher' Nasutitermes species (which do not contain cellulose-fermenting protozoa) to show the presence of a large, diverse set of bacterial genes for cellulose and xylan hydrolysis. Many of these genes were expressed in vivo or had cellulase activity in vitro, and further analyses implicate spirochete and fibrobacter species in gut lignocellulose degradation. New insights into other important symbiotic functions including H2 metabolism, CO2-reductive acetogenesis and N2 fixation are also provided by this first system-wide gene analysis of a microbial community specialized towards plant lignocellulose degradation. Our results underscore how complex even a 1-microl environment can be.
authors.affiliation: DOE Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, California 94598, USA.
authors.forename: Falk
authors.initials: F
authors.lastname: Warnecke
authors.forename: Peter
authors.initials: P
authors.lastname: Luginbühl
authors.forename: Natalia
authors.initials: N
authors.lastname: Ivanova
authors.forename: Majid
authors.initials: M
authors.lastname: Ghassemian
authors.forename: Toby H
authors.initials: TH
authors.lastname: Richardson
authors.forename: Justin T
authors.initials: JT
authors.lastname: Stege
authors.forename: Michelle
authors.initials: M
authors.lastname: Cayouette
authors.forename: Alice C
authors.initials: AC
authors.lastname: McHardy
authors.forename: Gordana
authors.initials: G
authors.lastname: Djordjevic
authors.forename: Nahla
authors.initials: N
authors.lastname: Aboushadi
authors.forename: Rotem
authors.initials: R
authors.lastname: Sorek
authors.forename: Susannah G
authors.initials: SG
authors.lastname: Tringe
authors.forename: Mircea
authors.initials: M
authors.lastname: Podar
authors.forename: Hector Garcia
authors.initials: HG
authors.lastname: Martin
authors.forename: Victor
authors.initials: V
authors.lastname: Kunin
authors.forename: Daniel
authors.initials: D
authors.lastname: Dalevi
authors.forename: Julita
authors.initials: J
authors.lastname: Madejska
authors.forename: Edward
authors.initials: E
authors.lastname: Kirton
authors.forename: Darren
authors.initials: D
authors.lastname: Platt
authors.forename: Ernest
authors.initials: E
authors.lastname: Szeto
authors.forename: Asaf
authors.initials: A
authors.lastname: Salamov
authors.forename: Kerrie
authors.initials: K
authors.lastname: Barry
authors.forename: Natalia
authors.initials: N
authors.lastname: Mikhailova
authors.forename: Nikos C
authors.initials: NC
authors.lastname: Kyrpides
authors.forename: Eric G
authors.initials: EG
authors.lastname: Matson
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Ottesen
authors.forename: Xinning
authors.initials: X
authors.lastname: Zhang
authors.forename: Myriam
authors.initials: M
authors.lastname: Hernández
authors.forename: Catalina
authors.initials: C
authors.lastname: Murillo
authors.forename: Luis G
authors.initials: LG
authors.lastname: Acosta
authors.forename: Isidore
authors.initials: I
authors.lastname: Rigoutsos
authors.forename: Giselle
authors.initials: G
authors.lastname: Tamayo
authors.forename: Brian D
authors.initials: BD
authors.lastname: Green
authors.forename: Cathy
authors.initials: C
authors.lastname: Chang
authors.forename: Edward M
authors.initials: EM
authors.lastname: Rubin
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Mathur
authors.forename: Dan E
authors.initials: DE
authors.lastname: Robertson
authors.forename: Philip
authors.initials: P
authors.lastname: Hugenholtz
authors.forename: Jared R
authors.initials: JR
authors.lastname: Leadbetter
mesh_terms: D000818:Animals; D001419:Bacteria / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001674:Bioelectric Energy Sources; D002244:Carbon / Q000378:metabolism; D020134:Catalytic Domain; D002482:Cellulose / Q000378:metabolism; D003364:Costa Rica; D005798:Genes, Bacterial / Q000235:genetics; D016680:Genome, Bacterial / Q000235:genetics*; D023281:Genomics; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006868:Hydrolysis; D007422:Intestines / Q000382:microbiology*; D020049:Isoptera / Q000378:metabolism* / Q000382:microbiology*; D008031:Lignin / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D013559:Symbiosis; D014934:Wood / Q000737:chemistry / Q000378:metabolism*; D014990:Xylans / Q000378:metabolism
chemical_list: D014990:Xylans; C036909:lignocellulose; D002244:Carbon; D002482:Cellulose; D008031:Lignin; D006026:Glycoside Hydrolases