Isolation of a strain from an Eastern Gray Kangaroo.

Methanogenic archaea are a group of microorganisms found in the gastrointestinal tract of various herbivores and humans; however, the quantity (intensity) of methane emissions during feed digestion varies. Macropodids, such as the Eastern Gray Kangaroo (), are considered to be low methane-emitting animals, but their gut methanogenic archaea remain poorly characterized. Characterizing methanogens from animals with low methane emissions offers the potential to develop strategies and interventions that reduce methane emissions from livestock.

Exploring the Origins and Evolution of Oxygenic and Anoxygenic Photosynthesis in Deeply Branched Cyanobacteriota.

Cyanobacteriota, the sole prokaryotes capable of oxygenic photosynthesis (OxyP), occupy a unique and pivotal role in Earth's history. While the notion that OxyP may have originated from Cyanobacteriota is widely accepted, its early evolution remains elusive. Here, by using both metagenomics and metatranscriptomics, we explore 36 metagenome-assembled genomes from hot spring ecosystems, belonging to two deep-branching cyanobacterial orders: Thermostichales and Gloeomargaritales.

Anaerobic gut fungal communities in marsupial hosts.

The anaerobic gut fungi (AGF) inhabit the alimentary tracts of herbivores. In contrast to placental mammals, information regarding the identity, diversity, and community structure of AGF in marsupials is extremely sparse. Here, we characterized AGF communities in 61 fecal samples from 10 marsupial species belonging to four families in the order Diprotodontia: Vombatidae (wombats), Phascolarctidae (koalas), Phalangeridae (possums), and Macropodidae (kangaroos, wallabies, and pademelons).

Isolation and characterisation of novel Methanocorpusculum species indicates the genus is ancestrally host-associated.

Background: With an increasing interest in the manipulation of methane produced from livestock cultivation, the microbiome of Australian marsupials provides a unique ecological and evolutionary comparison with 'low-methane' emitters. Previously, marsupial species were shown to be enriched for novel lineages of Methanocorpusculum, as well as Methanobrevibacter, Methanosphaera, and Methanomassiliicoccales. Despite sporadic reports of Methanocorpusculum from stool samples of various animal species, there remains little information on the impacts of these methanogens on their hosts.

The koala gut microbiome is largely unaffected by host translocation but rather influences host diet.

Introduction: Translocation is a valuable and increasingly used strategy for the management of both threatened and overabundant wildlife populations. However, in some instances the translocated animals fail to thrive. Differences in diet between the source and destination areas may contribute to poor translocation outcomes, which could conceivably be exacerbated if the animals' microbiomes are unsuited to the new diet and cannot adapt.

CYP108N12 initiates p-cymene biodegradation in Rhodococcus globerulus.

Rhodococcus globerulus (R. globerulus) isolated from soil beneath Eucalyptus sp. was found to live on the monoterpenes 1,8-cineole, p-cymene and (R)- and (S)-limonene as sole sources of carbon and energy.

Characterization of the juvenile koala gut microbiome across wild populations.

In this study we compared the faecal microbiomes of wild joey koalas (Phascolarctos cinereus) to those of adults, including their mothers, to establish whether gut microbiome maturation and inheritance in the wild is comparable to that seen in captivity. Our findings suggest that joey koala microbiomes slowly shift towards an adult assemblage between 6 and 12 months of age, as the microbiomes of 9-month-old joeys were more similar to those of adults than those of 7-month-olds, but still distinct. At the phylum level, differences between joeys and adults were broadly consistent with those in captivity, with Firmicutes increasing in relative abundance over the joeys' development and Proteobacteria decreasing.

Maternal inheritance of the koala gut microbiome and its compositional and functional maturation during juvenile development.

The acquisition and maturation of the gastrointestinal microbiome is a crucial aspect of mammalian development, particularly for specialist herbivores such as the koala (Phascolarctos cinereus). Joey koalas are thought to be inoculated with microorganisms by feeding on specialized maternal faeces (pap). We found that compared to faeces, pap has higher microbial density, higher microbial evenness and a higher proportion of rare taxa, which may facilitate the establishment of those taxa in joey koalas.

Prokaryotic taxonomy and nomenclature in the age of big sequence data.

The classification of life forms into a hierarchical system (taxonomy) and the application of names to this hierarchy (nomenclature) is at a turning point in microbiology. The unprecedented availability of genome sequences means that a taxonomy can be built upon a comprehensive evolutionary framework, a longstanding goal of taxonomists. However, there is resistance to adopting a single framework to preserve taxonomic freedom, and ever increasing numbers of genomes derived from uncultured prokaryotes threaten to overwhelm current nomenclatural practices, which are based on characterised isolates.

Faecal inoculations alter the gastrointestinal microbiome and allow dietary expansion in a wild specialist herbivore, the koala.

Background: Differences between individuals in their gastrointestinal microbiomes can lead to variation in their ability to persist on particular diets. Koalas are dietary specialists, feeding almost exclusively on Eucalyptus foliage but many individuals will not feed on particular Eucalyptus species that are adequate food for other individuals, even when facing starvation. We undertook a faecal inoculation experiment to test whether a koala's gastrointestinal (GI) microbiome influences their diet.

Evolution of photosynthesis and aerobic respiration in the cyanobacteria.

For well over a hundred years, members of the bacterial phylum Cyanobacteria have been considered strictly photosynthetic microorganisms, reflected in their classification as "blue-green algae" in the botanical code. Recently, genomes recovered from environmental sequencing surveys representing two major uncultured basal lineages (classes) of Cyanobacteria have been found to completely lack photosynthetic and CO fixation genes. The most likely explanation for this finding is that oxygenic photosynthesis was not an ancestral feature of the Cyanobacteria, and rather originated following divergence of the primary lines of descent.

Gene and genome-centric analyses of koala and wombat fecal microbiomes point to metabolic specialization for digestion.

The koala has evolved to become a specialist herbivore since diverging from its closest relative, the wombat, a generalist herbivore. This niche adaptation involves, in part, changes in the gut microbiota. The goal of this study was to compare koala and wombat fecal microbiomes using metagenomics to identify potential differences attributable to dietary specialization.

On the origins of oxygenic photosynthesis and aerobic respiration in Cyanobacteria.

The origin of oxygenic photosynthesis in Cyanobacteria led to the rise of oxygen on Earth ~2.3 billion years ago, profoundly altering the course of evolution by facilitating the development of aerobic respiration and complex multicellular life. Here we report the genomes of 41 uncultured organisms related to the photosynthetic Cyanobacteria (class ), including members of the class and a new class of Cyanobacteria (class ) that is basal to the and All members of the and lack photosynthetic machinery, indicating that phototrophy was not an ancestral feature of the Cyanobacteria and that acquired the genes for photosynthesis relatively late in cyanobacterial evolution.

Back from the dead; the curious tale of the predatory cyanobacterium Vampirovibrio chlorellavorus.

An uncultured non-photosynthetic basal lineage of the Cyanobacteria, the Melainabacteria, was recently characterised by metagenomic analyses of aphotic environmental samples. However, a predatory bacterium, Vampirovibrio chlorellavorus, originally described in 1972 appears to be the first cultured representative of the Melainabacteria based on a 16S rRNA sequence recovered from a lyophilised co-culture of the organism. Here, we sequenced the genome of V.

An expanded genomic representation of the phylum cyanobacteria.

Molecular surveys of aphotic habitats have indicated the presence of major uncultured lineages phylogenetically classified as members of the Cyanobacteria. One of these lineages has recently been proposed as a nonphotosynthetic sister phylum to the Cyanobacteria, the Melainabacteria, based on recovery of population genomes from human gut and groundwater samples. Here, we expand the phylogenomic representation of the Melainabacteria through sequencing of six diverse population genomes from gut and bioreactor samples supporting the inference that this lineage is nonphotosynthetic, but not the assertion that they are strictly fermentative.

Coral reef invertebrate microbiomes correlate with the presence of photosymbionts.

Coral reefs provide habitat for an array of marine invertebrates that host symbiotic microbiomes. Photosynthetic symbionts including Symbiodinium dinoflagellates and diatoms potentially influence the diversity of their host-associated microbiomes by releasing carbon-containing photosynthates and other organic compounds that fuel microbial metabolism. Here we used 16S ribosomal RNA (rRNA) gene amplicon pyrosequencing to characterise the microbiomes of 11 common Great Barrier Reef marine invertebrate species that host photosynthetic symbionts and five taxa in which they are absent.

Coral-bacterial communities before and after a coral mass spawning event on Ningaloo Reef.

Bacteria associated with three coral species, Acropora tenuis, Pocillopora damicornis and Tubastrea faulkneri, were assessed before and after coral mass spawning on Ningaloo Reef in Western Australia. Two colonies of each species were sampled before and after the mass spawning event and two additional samples were collected for P. damicornis after planulation.

The larval sponge holobiont exhibits high thermal tolerance.

Marine sponges are critical components of benthic environments; however, their sessile habit, requirement to filter large volumes of water and complex symbiotic partnerships make them particularly vulnerable to the effects of global climate change. We assessed the effect of elevated seawater temperature on bacterial communities in larvae of the Great Barrier Reef sponge, Rhopaloeides odorabile. In contrast to the strict thermal threshold of 32°C previously identified in adult R.

Elevated seawater temperature causes a microbial shift on crustose coralline algae with implications for the recruitment of coral larvae.

Crustose coralline algae (CCA) are key reef-building primary producers that are known to induce the metamorphosis and recruitment of many species of coral larvae. Reef biofilms (particularly microorganisms associated with CCA) are also important as settlement cues for a variety of marine invertebrates, including corals. If rising sea surface temperatures (SSTs) affect CCA and/or their associated biofilms, this may in turn affect recruitment on coral reefs.

Bacterial community dynamics in the marine sponge Rhopaloeides odorabile under in situ and ex situ cultivation.

Cultivation of sponges is being explored to supply biomaterial for the pharmaceutical and cosmetics industries. This study assesses the impact of various cultivation methods on the microbial community within the sponge Rhopaloeides odorabile during: (1) in situ cultivation under natural environmental conditions, (2) ex situ cultivation in small flow-through aquaria and (3) ex situ cultivation in large mesocosm systems. Principal components analysis of denaturing gradient gel electrophoresis profiles indicated a stable microbial community in sponges cultured in situ (grown in the wild) and in sponges cultured ex situ in small flow-through aquaria over 12 weeks.

Microbial biodiversity of thermophilic communities in hot mineral soils of Tramway Ridge, Mount Erebus, Antarctica.

Tramway Ridge, located near the summit of Mount Erebus in Antarctica, is probably the most remote geothermal soil habitat on Earth. Steam fumaroles maintain moist, hot soil environments creating extreme local physicochemical differentials. In this study a culture-independent approach combining automated rRNA intergenic spacer analysis (ARISA) and a 16S rRNA gene library was used to characterize soil microbial (Bacterial and Archaeal) diversity along intense physicochemical gradients.

Microbial community composition in soils of Northern Victoria Land, Antarctica.

Biotic communities and ecosystem dynamics in terrestrial Antarctica are limited by an array of extreme conditions including low temperatures, moisture and organic matter availability, high salinity, and a paucity of biodiversity to facilitate key ecological processes. Recent studies have discovered that the prokaryotic communities in these extreme systems are highly diverse with patchy distributions. Investigating the physical and biological controls over the distribution and activity of microbial biodiversity in Victoria Land is essential to understanding ecological functioning in this region.