Termite symbiotic systems: efficient bio-recycling of lignocellulose

  title={Termite symbiotic systems: efficient bio-recycling of lignocellulose},
  author={Moriya Ohkuma},
  journal={Applied Microbiology and Biotechnology},
  • M. Ohkuma
  • Published 14 January 2003
  • Biology
  • Applied Microbiology and Biotechnology
Termites thrive in great abundance in terrestrial ecosystems and play important roles in biorecycling of lignocellulose. Together with their microbial symbionts, they efficiently decompose lignocellulose. In so-called lower termites, a dual decomposing system, consisting of the termite's own cellulases and those of its gut protists, was elucidated at the molecular level. Higher termites degrade cellulose apparently using only their own enzymes, because of the absence of symbiotic protists… 

Termite digestomes as a potential source of symbiotic microbiota for lignocelluloses degradation: a review.

Future perspective should emphasize the isolation of cellulolytic strains from termites, genetically modifying or immobilization of the microbes which produce the desired enzyme and thus benefits on the microbiology and biotechnology.

Multiple Levels of Synergistic Collaboration in Termite Lignocellulose Digestion

Trans translational-genomic studies are undertook to gain unprecedented insights into digestion by the lower termite Reticulitermes flavipes and its symbiotic gut flora and provide important new evidence of synergistic collaboration among enzymes in the release of fermentable monosaccharides from wood lignocellulose.

Role of the Termite Gut Microbiota in Symbiotic Digestion

The symbiotic gut microbiota of termites plays important roles in lignocellulose digestion and nitrogen metabolism, and in wood-feeding termites, gut microbiota fix and upgrade nitrogen and recycle nitrogenous waste products.

Defining host-symbiont collaboration in termite lignocellulose digestion: “The view from the tip of the iceberg”

Termites have the unique ability to exploit lignocellulose as a primary nutrition source. Traditionally, termite lignocellulose digestion has been considered as a gut-symbiont-mediated process;

Termite digestomes as sources for novel lignocellulases

The topics covered in this review are lignocellulose structure with emphasis on its potential for depolymerization by termite and gut endosymbiont‐derived digestive enzymes; termite biology and ecology from the perspectives of termite nutrition, gut physiology, and ligni cellulose digestion; and trends identified through recent termite digestomics research.

Tripartite Symbiotic Digestion of Lignocellulose in the Digestive System of a Fungus-Growing Termite

The findings suggest that although the first gut passage initiates lignocellulose digestion, the most prominent decomposition occurs within the fungus comb, and distinct bacterial communities were associated with different stages of decomposition, potentially contributing to the breakdown of particular plant components.

Phylogenetic Analysis of Cellulolytic Enzyme Genes from Representative Lineages of Termites and a Related Cockroach

According to phylogenetic analyses, the enzymes comprising the protistan lignocellulose degradation system are coded not only by genes innate to the protists, but also genes acquired by the protist via lateral transfer from bacteria, giving a fresh perspective from which to understand the evolutionary dynamics of symbiosis.

Lignin-associated metagene expression in a lignocellulose-digesting termite.

Diversity, Structure, and Evolution of the Termite Gut Microbial Community

The complete genome sequences of several bacterial endosymbionts have disclosed their functional interactions with their host flagellates, but the highly structured and coevolving nature of these associations requires more emphasis in future studies.



Symbiosis in the Termite Gut

The recent application of culture-independent molecular approaches provides a new way to characterize the microbial populations in the symbiotic community in the termite gut, and the structure and functions of the gut community should be extensively characterized in some model termites.

Hemicellulose-degrading bacteria and yeasts from the termite gut.

The spectrum and activity of xylan- and arabinogalactan-hydrolysing glycosidases of these new isolates, together with additional bacterial strains originally obtained from enrichments with aromatic compounds were determined.

The gut microflora of Reticulitermes flavipes, its relation to oxygen, and evidence for oxygen-dependent acetogenesis by the most abundant Enterococcus sp.

The gut microflora of the wood-feeding termite Reticulitermes flavipes is characterized, showing that the isolate Enterococcus strain RfL6, representing the most abundant physiotype among the carbohydrate-utilizing gut bacteria, was not purely fermentative, but consumed oxygen during growth on glucose, accompanied by a complete shift in the product spectrum from lactate to acetate, and was able to oxidize lactateto acetate when oxygen was present.

Localization and In Situ Activities of Homoacetogenic Bacteria in the Highly Compartmentalized Hindgut of Soil-Feeding Higher Termites (Cubitermes spp.)

It is concluded that the homoacetogenic populations in the posterior hindgut are supported by either substrates other than H2 or by a cross-epithelial H2transfer from the anterior gut regions, which may create microniches favorable for H2-dependent acetogenesis.

Impact of oxygen on metabolic fluxes and in situ rates of reductive acetogenesis in the hindgut of the wood-feeding termite Reticulitermes flavipes.

A refined model of metabolic fluxes in the hindgut of R. flavipes adds strong support to the hypothesis that the co-existence of methanogens and homoacetogens in this termite is based on the spatial arrangement of the different populations of the gut microbiota.

Molecular phylogenetic profiling of prokaryotic communities in guts of termites with different feeding habits.

The relative abundances of 16S-like archaeal rRNA in guts were positively correlated with rates of methane emission by live termites, and were consistent with previous work linking high relative rates of methanogenesis with the soil (humus)-feeding habit.

Acetogenesis from Carbon Dioxide in Termite Guts

During microbial fermentation in the gut of certain termites, in particular, acetogens not only appear to constitute the primary H2 sink, but their production of acetate from H2 + CO2 makes a major contribution to termite nutrition.