title: Microenvironmental heterogeneity of gut compartments drives bacterial community structure in wood- and humus-feeding higher termites.
abstract: Symbiotic digestion of lignocellulose in higher termites (family Termitidae) is accomplished by an exclusively prokaryotic gut microbiota. By deep sequencing of amplified 16S rRNA genes, we had identified diet as the primary determinant of bacterial community structure in a broad selection of termites specialized on lignocellulose in different stages of humification. Here, we increased the resolution of our approach to account for the pronounced heterogeneity in microenvironmental conditions and microbial activities in the major hindgut compartments. The community structure of consecutive gut compartments in each species strongly differed, but that of homologous compartments clearly converged, even among unrelated termites. While the alkaline P1 compartments of all termites investigated contained specific lineages of Clostridiales, the posterior hindgut compartments (P3, P4) differed between feeding groups and were predominantly colonized by putatively fiber-associated lineages of Spirochaetes, Fibrobacteres and the TG3 phylum (wood and grass feeders) or diverse assemblages of Clostridiales and Bacteroidetes (humus and soil feeders). The results underscore that bacterial community structure in termite guts is driven by microenvironmental factors, such as pH, available substrates and gradients of O2and H2, and inspire investigations on the functional roles of specific bacterial taxa in lignocellulose and humus digestion.
authors: Department of Biogeochemistry, Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany.
authors: Aram
authors: A
authors: Mikaelyan
authors: Department of Biogeochemistry, Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany.
authors: Katja
authors: K
authors: Meuser
authors: Department of Biogeochemistry, Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany brune@mpi-marburg.mpg.de.
authors: Andreas
authors: A
authors: Brune
mesh_terms: D000818:Animals; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D004064:Digestive System / Q000382:microbiology; D005247:Feeding Behavior; D000069196:Gastrointestinal Microbiome; D059014:High-Throughput Nucleotide Sequencing; D020049:Isoptera / Q000382:microbiology* / Q000502:physiology; D008031:Lignin / Q000378:metabolism; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D012987:Soil / Q000737:chemistry; D014934:Wood / Q000382:microbiology*
chemical_list: D012987:Soil; C036909:lignocellulose; D008031:Lignin
keywords: gut microbiota; insects; microhabitats; termites