Phylogenetic Diversity of Symbiotic Methanogens Living in the Hindgut of the Lower Termite
            <i>Reticulitermes speratus</i>
            Analyzed by PCR and In Situ Hybridization

The molecular phylogeny of methanogenic archaea associated with the flagellated protist species Dinenympha and Microjoenia in the gut of termites, Reticulitermes speratus and Hodotermopsis sjoestedti, and those attached to the gut epithelium was examined based on PCRamplified small-subunit ribosomal RNA genes. The sequences identified were classified into six groups within the genus Methanobrevibacter, including groups of yet uncharacterized novel species. Closely related methanogens were shared between Microjoenia and some Dinenympha cells in each termite. The methanogens harbored by the flagellates were phylogenetically different from the methanogens associated with the gut epithelium, suggesting that distinct methanogen species showed distinct spatial distributions in the termite gut. ß

Section: Discussionsupporting

confidence: 63%

Section: Discussionmentioning

confidence: 99%

Molecular phylogeny of methanogens associated with flagellated protists in the gut and with the gut epithelium of termites

Tokura

2000

“…The big difference in diversity between the Bacteria and Archaea domains found in pig manure slurry has also been observed in various anaerobic digestion ecosystems, such as an anaerobic digester [21], termite intestinal tract [51,52], rumen [44,53], a contaminated aquifer [41] and sediments [54,55]. This is due to the simplification of substrates, both in number and complexity, through the trophic chain involved in anaerobic degradation of organic matter [56].…”

Section: Discussionmentioning

confidence: 99%

Characterisation of the microbial diversity in a pig manure storage pit using small subunit rDNA sequence analysis

Snell‐Castro

Godon

Delgenès

et al. 2005

145

103

The microbial community structure of pig manure slurry (PMS) was determined with comparative analysis of 202 bacterial, 44 archaeal and 33 eukaryotic small subunit (SSU) rDNA partial sequences. Based on a criterion of 97% of sequence similarity, the phylogenetic analyses revealed a total of 108, eight and five phylotypes for the Bacteria, Archaea and Eukarya lineages, respectively. Only 36% of the bacterial phylotypes were closely related (>or=97% similarity) to any previously known sequence in databases. The bacterial groups most often represented in terms of phylotype and clone abundance were the Eubacterium (22% of total sequences), the Clostridium (15% of sequences), the Bacillus-Lactobacillus-Streptococcus subdivision (20% of sequences), theMycoplasma and relatives (10% of sequences) and the Flexibacter-Cytophaga-Bacteroides (20% of sequences). The global microbial community structure and phylotype diversity show a close relationship to the pig gastrointestinal tract ecosystem whereas phylotypes from the Acholeplasma-Anaeroplasma and the Clostridium purinolyticum groups appear to be better represented in manure. Archaeal diversity was dominated by three phylotypes clustering with a group of uncultured microorganisms of unknown activity and only distantly related to the Thermoplasmales and relatives. Other Archaea were methanogenic H2/CO2 utilisers. No known acetoclastic Archaea methanogen was found. Eukaryotic diversity was represented by a pluricellular nematode, two Alveolata, a Blastocystis and an Entamoebidae. Manure slurry physico-chemical characteristics were analysed. Possible inhibitory effects of acetate, sulphide and ammonia concentrations on the microbial anaerobic ecosystem are discussed.

“…Prevalence of Methanobacteriaceae in guts of diverse termite taxa is consistent with previous studies of individual termite species. For example : (i) Yang et al [40] reported the presence of Methanobrevibacter arboriphilicus and Methanobacterium bryantii in guts of two wood-feeding termitids, Nasutitermes costalis and Nasutitermes nigriceps; (ii) M. cuticularis, M. curvatus and Methanobrevibacter ¢liformis, three methanobrevibacters isolated from R. £avipes guts [18,19], are members of the Methanobacteriaceae ; and (iii) PCR ampli¢cation, sequencing and phylogenetic analysis of 16S rRNA genes in guts of the termite Reticulitermes speratus [41,42] detected Archaea mostly a¤liated with the order Methanobacteriales. A limited diversity of methanogen families, and the prominence of members of the Methanobacteriaceae seem to be a general feature of gastrointestinal ecosystems [30,31,43].…”

Section: Methanogen Population Compositionmentioning

confidence: 99%

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

Brauman¹

2001

Termites are an important group of terrestrial insects that harbor an abundant gut microbiota, many of which contribute to digestion, termite nutrition and gas (CH 4 , CO 2 and H 2 ) emission. With 2200 described species, termites also provide a good model to study relationships between host diet and gut microbial community structure and function. We examined the relationship between diet and gut prokaryotic community profiles in 24 taxonomically and nutritionally diverse species of termites by using nucleic acid probes targeting 16Slike ribosomal RNAs. The relative abundance of domain-specific 16S-like rRNAs recovered from gut extracts varied considerably (ranges: Archaea (0^3%); Bacteria (15^118%)). Although Bacteria were always detectable and the most abundant, differences in domain-level profiles were correlated with termite diet, as evidenced by higher relative abundances of Archaea in guts of soil-feeding termites, compared to those of wood-feeding species in the same family. The oligonucleotide probes also readily distinguished gut communities of wood-feeding taxa in the family Termitidae (higher termites) from those of other wood-feeding termite families (lower termites). 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. Probes for methanogenic Archaea detected members of only two families (Methanobacteriaceae and Methanosarcinaceae) in termite guts, and these typically accounted for 60% of the all archaeal probe signal. In four species of termites, Methanosarcinaceae were dominant, a novel observation for animal gut microbial communities, but no clear relationship was apparent between methanogen family profiles and termite diet or taxonomy. ß FEMS Microbiology Ecology 35 (2001) 27^36 www.fems-microbiology.org A. Brauman et al. / FEMS Microbiology Ecology 35 (2001) 27^36