Andreas Brune

Max Planck Institute for Terrestrial Microbiology | MPITM · Research Group Insect Gut Microbiology and Symbiosis

Spirochetes of the genus Treponema are surprisingly abundant in termite guts, where they play an important role in reductive acetogenesis. Although they occur in all termites investigated, their evolutionary origin is obscure. Here, we isolated the first representative of ‘termite gut treponemes’ from cockroaches, the closest relatives of termites....

The intestinal tracts of termites are abundantly colonized by a diverse assemblage of spirochetes. Most of them belong to ‘termite cluster I’, a monophyletic group within the radiation of the genus Treponema that occurs exclusively in termite guts. Phylogenomic analysis revealed that members of the genus Treponema are extremely diverse and represen...

Most members of the family Treponemataceae (Spirochaetales) are associated with vertebrate hosts. However, a diverse clade of uncultured, putatively free-living treponemes comprising several genus-level lineages is present in other anoxic environments. The only cultivated representative to date is Treponema zuelzerae, isolated from freshwater mud....

Lower termites harbor diverse consortia of symbiotic gut flagellates. Despite numerous evidence for co-cladogenesis, the evolutionary history of these associations remains unclear. Here, we present Retractinymphidae fam. nov., a monogeneric lineage of Trichonymphida from Serritermitidae. Although Retractinympha glossotermitis gen. nov. sp. nov. mor...

E.lu.si.mi.cro.bi.o'ta. N.L. neut. n. Elusimicrobium, type genus of the phylum; N.L. neut. pl. n. suff. ‐ota, ending to denote a phylum; N.L. neut. pl. n. Elusimicrobiota, the Elusimicrobium phylum. Elusimicrobiota belongs to the PVC superphylum and comprises at least four class‐level lineages of mostly uncultured bacteria. Only the classes Elusimi...

Small genes (<150 nucleotides) have been systematically overlooked in phage genomes. We employ a large-scale comparative genomics approach to predict >40,000 small-gene families in ∼2.3 million phage genome contigs. We find that small genes in phage genomes are approximately 3-fold more prevalent than in host prokaryotic genomes. Our approach enric...

Background Termites primarily feed on lignocellulose or soil in association with specific gut microbes. The functioning of the termite gut microbiota is partly understood in a handful of wood-feeding pest species but remains largely unknown in other taxa. We intend to fill this gap and provide a global understanding of the functional evolution of t...

Termites primarily feed on lignocellulose or soil in association with specific gut microbes. The functioning of the termite gut microbiota is partly understood in a handful of wood-feeding pest species, but remains largely unknown in other taxa. We intend to feel this gap and provide a global understanding of the functional evolution of termite gut...

Methanogens represent the final decomposition guild in anaerobic degradation of organic matter, occurring in digestive tract of various invertebrates. However, factors determining their community structure and activity in distinct gut sections is still debated. In this study, we focused on the tropical millipede species Archispirostreptus gigas (Di...

A Correction to this paper has been published: https://doi.org/10.1038/s41587-021-00898-4.

Symbiotic digestion of lignocellulose in the hindgut of higher termites is mediated by a diverse assemblage of bacteria and archaea. During a large-scale metagenomic study, we reconstructed 15 metagenome-assembled genomes (MAGs) of Bathyarchaeia that represent two distinct lineages in subgroup 6 (formerly MCG-6) unique to termite guts. One lineage...

Nephridiophagids are unicellular eukaryotes that parasitize the Malpighian tubules of numerous insects. Their life cycle comprises multinucleate vegetative plasmodia that divide into oligonucleate and uninucleate cells, and sporogonial plasmodia that form uninucleate spores. Nephridiophagids are poor in morphological characteristics, and although t...

Symbiotic digestion of lignocellulose in the hindgut of higher termites is mediated by a diverse assemblage of bacteria and archaea. During a large-scale metagenomic study, we reconstructed 15 metagenome-assembled genomes (MAGs) of Bathyarchaeia that represent two distinct lineages in subgroup 6 (formerly MCG-6) unique to termite guts. One lineage...

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Nephridiophagids are unicellular eukaryotes that parasitize the Malpighian tubules of numerous insects. Their life cycle comprises multinucleate vegetative plasmodia that divide into oligonucleate and uninucleate cells, and sporogonial plasmodia that form uninucleate spores. Nephridiophagids are poor in morphological characteristics, and although t...

Methanogenesis is the final step in the anaerobic degradation of organic matter. The most important substrates of methanogens are hydrogen plus carbon dioxide and acetate, but also the use of methanol, methylated amines, and aromatic methoxy groups appears to be more widespread than originally thought. Except for most members of the family Methanos...

“Higher” termites have been able to colonize all tropical and subtropical regions because of their ability to digest lignocellulose with the aid of their prokaryotic gut microbiota. Over the last decade, numerous studies based on 16S rRNA gene amplicon libraries have largely described both the taxonomy and structure of the prokaryotic communities a...

Although mutualistic associations between animals and microbial symbionts are widespread in nature, the mechanisms that have promoted their evolutionary persistence remain poorly understood. A vertical mode of symbiont transmission (from parents to offspring) is thought to ensure partner fidelity and stabilisation, although the efficiency of vertic...

Background: Diet is a major determinant of bacterial community structure in termite guts, but evidence of its importance in the closely related cockroaches is conflicting. Here, we investigated the ecological drivers of the bacterial gut microbiota in cockroaches that feed on lignocellulosic leaf litter. Results: The physicochemical conditions d...

The symbiotic gut flagellates of lower termites form host-specific consortia composed of Parabasalia and Oxymonadida. The analysis of their coevolution with termites is hampered by a lack of information, particularly on the flagellates colonizing the basal host lineages. To date, there are no reports on the presence of oxymonads in termites of the...

“Higher” termites have been able to colonize all tropical and subtropical regions because of their ability to digest lignocellulose with the aid of their prokaryotic gut microbiota. Over the last decade, numerous studies based on 16S rRNA gene amplicon libraries have largely described both the taxonomy and structure of the prokaryotic communities a...

“Higher” termites have been able to colonize all tropical and subtropical regions because of their ability to digest lignocellulose with the aid of their prokaryotic gut microbiota. Over the last decade, numerous studies based on 16S rRNA gene amplicon libraries have largely described both the taxonomy and structure of the prokaryotic communities a...

Symbiotic digestion of lignocellulose in wood-feeding higher termites (family Termitidae) is a two-step process that involves endogenous host cellulases secreted in the midgut and a dense bacterial community in the hindgut compartment. The genomes of the bacterial gut microbiota encode diverse cellulolytic and hemicellulolytic enzymes, but the cont...

The ability to digest lignocellulose with the help of their prokaryotic gut microbiota has enabled higher termites to colonize all tropical and subtropical regions. Over the last decade, numerous studies based on 16S rRNA gene amplicon libraries have largely described both the taxonomy and the structure of the prokaryotic communities associated wit...

E.lu.si.mi.cro'bi.um. L. part. adj. elusus (from L. v. eludo), to elude, parry (with the accessory notion of mockery); here intended to mean escaped from capture; N.L. neut. n. microbium, a microbe; N.L. neut. n. Elusimicrobium, an elusive microbe, hard to find, capture, or isolate. Elusimicrobia / Elusimicrobia / Elusimicrobiales / Elusimicrobiace...

E.lu.si.mi.cro'bi.a. N.L. fem. pl. n. Elusimicrobiales type order of the phylum; dropping ending ‐ales and inserting ‐a to denote a phylum; N.L. fem. pl. n. Elusimicrobia the phylum of Elusimicrobiales. Elusimicrobia The phylum Elusimicrobia contains two classes, Elusimicrobia and Endomicrobia, each of which contains only a single cultured represen...

En.do.mi.cro'bi.um. Pref. endo‐ (from Gr. endon, within); N.L. neut. n. microbium, microbe; N.L. neut. n. Endomicrobium, a microbe within (an endosymbiont). Elusimicrobia / Endomicrobia / Endomicrobiales / Endomicrobiaceae / Endomicrobium Ultramicrobacteria with a Gram‐negative cell envelope. Cells are nonmotile, pleomorphic rods, sometimes spindle...

En.do.mi.cro.bi.a.ce'ae. N.L. neut. n. Endomicrobium type genus of the family; suff. ‐aceae to denote a family; N.L. fem. pl. n. Endomicrobiaceae the family of Endomicrobium. Elusimicrobia / Endomicrobia / Endomicrobiales / Endomicrobiaceae The family Endomicrobiaceae currently accommodates only a single species, the ultramicrobacterium Endomicrobi...

En.do.mi.cro'bi.a. N.L. fem. pl. n. Endomicrobiales type order of the class; dropping ending ‐ales and inserting ‐a to denote a class; N.L. neut. pl. n. Endomicrobia the class of Endomicrobiales. Elusimicrobia / Endomicrobia The class Endomicrobia currently contains the order Endomicrobiales, which accommodates only a single species, the ultramicro...

E.lu.si.mi.cro.bi.a.ce'ae. N.L. neut. n. Elusimicrobium type genus of the family; suff. ‐aceae to denote a family; N.L. fem. pl. n. Elusimicrobiaceae, the family of Elusimicrobium. Elusimicrobia / Elusimicrobia / Elusimicrobiales / Elusimicrobiaceae The family Elusimicrobiaceae currently accommodates only a single species, the ultramicrobacterium E...

E.lu.si.mi.cro'bi.a. N.L. fem. pl. n. Elusimicrobiales type order of the class; dropping ending ‐ales and inserting ‐a to denote a class; N.L. neut. pl. n. Elusimicrobia the class of Elusimicrobiales. Elusimicrobia / Elusimicrobia The class Elusimicrobia currently contains the order Elusimicrobiales, which accommodates only a single species, the ul...

En.do.mi.cro.bi.a'les. N.L. neut. n. Endomicrobium type genus of the order; suff. ‐ales to denote an order; N.L. fem. pl. n. Endomicrobiales the order of Endomicrobium. Elusimicrobia / Endomicrobia / Endomicrobiales The order Endomicrobiales currently contains the family Endomicrobiaceae, which accommodates only a single species, the ultramicrobact...

E.lu.si.mi.cro.bi.a'les. N.L. neut. n. Elusimicrobium type genus of the order; suff. ‐ales to denote an order; N.L. fem. pl. n. Elusimicrobiales the order of Elusimicrobium. Elusimicrobia / Elusimicrobia / Elusimicrobiales The order Elusimicrobiales currently contains the family Elusimicrobiaceae, which accommodates only a single species, the ultra...

The gut microbiota of animals exert major effects on host biology [1]. Although horizontal transfer is generally considered the prevalent route for the acquisition of gut bacteria in mammals [2], some bacterial lineages have co-speciated with their hosts on timescales of several million years [3]. Termites harbor a complex gut microbiota, and their...

Methanogenesis in termite guts is a product of symbiotic digestion, fueled by hydrogen and reduced one-carbon compounds that are formed during the fermentative breakdown of plant fiber and humus. Methanogens are restricted to the hindgut region and can be found in several distinct microhabitats. In lower termites, the methanogens belong almost excl...

We isolated a novel member of the phylum Verrucomicrobia from the hindgut of the cockroach Shelfordella lateralis. Strain Ho45 is a yellow-pigmented, motile coccus that represents a new genus-level lineage with less than 93% sequence similarity to the 16S rRNA genes of other species in the family Opitutaceae. Ultrastructural analysis revealed a Gra...

The guts of lower termites are inhabited by host-specific consortia of cellulose-digesting flagellate protists. In this first investigation of the symbionts of the family Serritermitidae, we found that Glossotermes oculatus and Serritermes serrifer each harbor similar parabasalid morphotypes: large Pseudotrichonympha-like cells, medium-sized Leptos...

Bacteria of the class Endomicrobia form a deep-branching clade in the Elusimicrobia phylum. They are found almost exclusively in the intestinal tract of animals and are particularly abundant in many termites, where they reside as intracellular symbionts in the cellulolytic gut flagellates. Although small populations of putatively free-living lineag...

Bacterial endosymbionts of eukaryotes show progressive genome erosion, but detailed investigations of the evolutionary processes involved in the transition to an intracellular lifestyle are generally hampered by the lack of extant freeliving lineages. Here, we characterize the genome of the recently isolated, free-living Endomicrobium proavitum, th...

The complete mitochondrial genomes (mitogenomes) of two higher termites were reconstructed from the metagenomes of individual gut compartments with more than 2000-fold coverage. The circular mitogenomes of Labiotermes labralis (accession number KY436201) and Embiratermes neotenicus (accession number KY436202) have a length of 15,935 and 15,868 bp a...

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 stag...

The flagellate protists in the hindgut of lower termites play an essential role in the digestion of lignocellulose. Most flagellate species are associated with host-specific symbionts from various bacterial lineages, which typically lack cultured representatives. In this study, we analyzed the genome of ‘Candidatus Ancillula trichonymphae', an endo...

Mutualistic associations of bacteria and invertebrates are widespread and encompass an enormous diversity on the side of both partners. The advantages gained from the symbiosis favour reciprocal adaptations that increase the stability of the association and can lead to codiversification of symbiont and host. While numerous examples of a strictly ve...

Two novel, obligately anaerobic Firmicutes from the family Erysipelotrichaceae were isolated from the intestinal tracts of a cockroach (strain ErySL, Shelfordella lateralis) and a scarab beetle larva (strain Pei061, Pachnoda ephippiata). Phylogenetic analysis indicated that the strains belong to a monophyletic group of hitherto uncultured bacteria...

Termite gut flagellates are typically colonized by specific bacterial symbionts. Here we describe the phylogeny, ultrastructure, and subcellular location of 'Candidatus Adiutrix intracellularis', an intracellular symbiont of Trichonympha collaris in the termite Zootermopsis nevadensis. It represents a novel, deep-branching clade of uncultured Delta...

The gut microbiota of termites plays important roles in the symbiotic digestion of lignocellulose. However, the factors shaping microbial community structure remain poorly understood. Because termites cannot be raised under axenic conditions, we established the closely related cockroach Shelfordella lateralis as a germ-free model to study microbial...

The gut microbiota of termites and cockroaches represents complex metabolic networks of many diverse microbial populations. The distinct microenvironmental conditions within the gut and possible interactions among the microorganisms make it essential to investigate how far the metabolic properties of pure cultures reflect their activities in their...

Background: Termites are important contributors to carbon and nitrogen cycling in tropical ecosystems. Higher termites digest lignocellulose in various stages of humification with the help of an entirely prokaryotic microbiota housed in their compartmented intestinal tract. previous studies revealed fundamental differences in community structure be...

Long-term vertical transmission of intracellular bacteria causes massive genomic erosion and results in extremely small genomes, particularly in ancient symbionts. Genome reduction is typically preceded by the accumulation of pseudogenes and proliferation of mobile genetic elements, which are responsible for chromosome rearrangements during the ini...

The gut microbiota of termites plays critical roles in the symbiotic digestion of lignocellulose. While phylogenetically “lower termites” are characterized by a unique association with cellulolytic flagellates, higher termites (family Termitidae) harbor exclusively prokaryotic communities in their dilated hindguts. Unlike the more primitive termite...

Termite guts harbor a dense and diverse microbiota that is essential for symbiotic digestion. The major players in lower termites are unique lineages of cellulolytic flagellates, whereas higher termites harbor only bacteria and archaea. The functions of the mostly uncultivated lineages and their distribution in different diet groups are slowly emer...

Fungus-cultivating termites (Macrotermitinae) possess an elaborate strategy of lignocellulose digestion. It involves a lignocellulose-degrading fungal symbiont (genus Termitomyces), a diverse gut microbiota, and a characteristic labor division in food processing. In this study, using pyrotag sequencing and electron microscopy, we analyzed the bacte...

I.ly.o.bac'ter. Gr. fem. n. ilys mud; N.L. masc. n. bacter rod; N.L. masc. n. Ilyobacter a mud-inhabiting rod. Fusobacteria / Fusobacteriia / Fusobacteriales / Fusobacteriaceae / Ilyobacter Strictly anaerobic chemoorganotrophic bacteria with fermentative metabolism, nonphotosynthetic, inorganic electron acceptors not used. Nonsporeforming. DNA G+C...

Recent developments in sequencing technology have given rise to a large number of studies that assess bacterial diversity and community structure in termite and cockroach guts based on large amplicon libraries of 16S rRNA genes. Although these studies have revealed important ecological and evolutionary patterns in the gut microbiota, classification...

We sequenced the complete genome of Endomicrobium proavitum strain Rsa215, the first isolate of the class Endomicrobia (phylum Elusimicrobia). It is the closest free-living relative of the endosymbionts of termite gut flagellates and thereby provides an excellent model for studying the evolutionary processes during the establishment of an intracell...

The bacterial tree contains many deep-rooting clades without any cultured representatives. One such clade is "Endomicrobia", a class-level lineage in the phylum Elusimicrobia represented so far only by intracellular symbionts of termite gut flagellates. Here, we report the isolation and characterization of the first free-living member of this clade...

The gut microbiota of many phylogenetically lower termites is dominated by cellulolytic flagellates of the genus Trichonympha, which are consistently associated with bacterial symbionts. In the case of Endomicrobia, an unusual lineage of endosymbionts of the Elusimicrobia phylum that is present also in other gut flagellates, previous studies have d...

The recently discovered seventh order of methanogens, the Methanomassiliicoccales (previously referred to as "Methanoplasmatales") so far consist exclusively of obligately hydrogen-dependent methylotrophs. We sequenced the complete genome of "Candidatus Methanoplasma termitum" from a highly enriched culture obtained from the intestinal tract of ter...

Abstract We reconstructed the complete mitochondrial genomes of six higher termite species from metagenomic datasets of their isolated hindgut compartments. The sequencing reads were retrieved and assembled with the mitochondrial-baiting and iterative-mapping algorithm (MITObim), which yielded closed mitogenomes without additional finishing efforts...

Gut microbes play a crucial role in decomposing lignocellulose to fuel termite societies, with protists in the lower termites and prokaryotes in the higher termites providing these services. However, a single basal subfamily of the higher termites, the Macrotermitinae, also domesticated a plant biomass-degrading fungus (Termitomyces), and how this...

The family Elusimicrobiaceae contains only a single species, Elusimicrobium minutum, whose uncultured relatives are found in the intestinal tracts of insects and vertebrates. E. minutum is an obligately anaerobic ultramicrobacterium that ferments glucose and only a few other sugars in an unusual mixed-acid fermentation that involves the production...

The saprophagous larvae of bibionid flies harbor bacteria in their alkaline intestinal tracts, but little is known about the contribution of the gut microbiota to the digestion of their recalcitrant diet. In this study, we measured oxygen and hydrogen partial pressure, redox potential and pH in the midgut, gastric caeca and hindgut of larvae of the...

The biodiversity of oxymonadid flagellates in termite hindguts is not fully explored. Many species have been differentiated only by morphological features, and small-celled species have been overlooked or ignored. Our analysis of the dry wood termite Neotermes jouteli by light and electron microscopy revealed the presence of two distinct morphotype...

While the gut microbiota of termites and its role in symbiotic digestion have been studied for decades, little is known about the bacteria colonizing the intestinal tract of the distantly related wood-feeding cockroaches (Blaberidae: Panesthiinae). Here, we show that physicochemical gut conditions and microbial fermentation products in the gut of P...

Their ability to degrade lignocellulose gives termites an important place in the carbon cycle. This ability relies on their partnership with a diverse community of bacterial, archaeal and eukaryotic gut symbionts, which break down the plant fibre and ferment the products to acetate and variable amounts of methane, with hydrogen as a central interme...

Termites digest lignocellulose with the help of their symbiotic gut microbiota. In the hindgut of evolutionary lower termites, a dense community of cellulolytic flagellates sequesters wood particles from the hindgut content into their digestive vacuoles. In higher termites (family Termitidae), which possess an entirely prokaryotic microbiota, the w...

Termites digest wood and other lignocellulosic substrates with the help of their intestinal microbiota. While the functions of the symbionts in the digestive process are slowly emerging, the origin of the bacteria colonizing the hindgut bioreactor is entirely in the dark. Recently, our group discovered numerous representatives of bacterial lineages...

Although blattid cockroaches and termites share a common ancestor, their diets are distinctly different. While termites consume a highly specialized diet of lignocellulose, cockroaches are omnivorous and opportunistic feeders. The role of the termite gut microbiota has been studied intensively, but little is known about the cockroach gut microbiota...

The symbiotic associations of termites with microorganisms comprise different levels of interaction, ranging from the extracorporeal cultivation of fungus gardens to the most intimate associations, where bacteria reside intracellularly in dedicated bacteriocytes. However, the majority of prokaryotic symbionts of termites are located in the intestin...

Humic substances play a key role in the global carbon cycling and the sequestration of micropollutants in soil. The transformation of these substances by earthworms, the dominant soil macroinvertebrates of many terrestrial ecosystems, and the mechanisms involved are still obscure. We prepared two chemically identical humic model compounds that were...

Endomicrobia are endosymbiotic bacteria that represent a deep-branching lineage in the phylum Elusimicrobia. They colonize the cytoplasm of termite gut flagellates and are specific for their flagellate hosts. Co-speciation of Endomicrobia with flagellates of the genus Trichonympha indicates a vertical transfer of the symbionts and an obligate depen...

The Euryarchaeota comprise both methanogenic and nonmethanogenic orders and many lineages of uncultivated archaea with unknown properties. One of these deep-branching lineages, distantly related to the Thermoplasmatales, has been discovered in various environments, including marine habitats, soil, and also the intestinal tracts of termites and mamm...

Termite gut flagellates are colonized by host-specific lineages of ectosymbiotic and endosymbiotic bacteria. Previous studies have shown that flagellates of the genus Trichonympha may harbour more than one type of symbiont. Using a comprehensive approach that combined cloning of SSU rRNA genes with fluorescence in situ hybridization and electron mi...