Diversity of Gut Methanogens and Functional Enzymes Associated With Methane Metabolism in Smallholder Dairy Cattle

Methane is a greenhouse gas with disastrous consequences when released to intolerable levels. Ruminants produce methane during gut fermentation releasing it through belching and/or flatulence. To better understand the diversity of methanogens and functional enzymes associated with methane metabolism in dairy cows, 48 samples; six rumen and 42 dung contents were collected and analyzed using a shotgun metagenomic approach. The results indicated archaea from 5 phyla, 9 classes, 16 orders, 25 families, 59 genera, and 87 species. Gut sites significantly contributed to the presence and distribution of various methanogens (P<0.01). The class Methanomicrobia was abundant in the rumen samples (~ 39%) and in dung (~44%). The most abundant (~17%) methanogen species identified was Methanocorpusculum labreanum. However, some taxonomic classes were not classified (~ 6% in the rumen and ~4% in the dung). Furthermore, five functional enzymes: Glycine/Serine hydroxy methyltransferase, Formylmethanofuran—tetrahydromethanopterin N-formyltransferase, Formate dehydrogenase, Anaerobic carbon monoxide dehydrogenase and Catalase-peroxidase were associated with methane metabolism. KO0600 module and Enzyme Commissions (1.11.1.6 & 2.1.2.1) were common for dung and rumen fluid’s enzymatic pathways. Functional analysis for the enzymes identified were significant (P<0.05) for 5 metabolism processes. Breeding for tolerable methane emitting dairy cattle for a sustainable environment should be undertaken.

Characterization of Biological Aerosols Over Northeast India: A Metagenomic Approach

Northeast India is considered as one of the major biodiversity hotspots in the world but the region is underexplored for their microbial biodiversity. Extensive characterization of biological aerosol (bioaerosol) samples collected from various locations of Northeast India was carried out for all the four seasons in a year. These were characterized in terms of particulate matters (inhalable, thoracic, and alveolic), their constituents (pollens, fungal spores, animal debris, and non-biological components), and finally the bacterial diversity was determined by DNA based metagenomic approach. The non-biological (non-viable) component of aerosols is found to vary from 30- 89% in pre-monsoon season which coexists with pollens (4-20%), animal debris (1-24%) and fungal spores (1-17%). The highest number of culturable microbial population in terms of CFU count was observed in the samples collected in pre-monsoon season (i.e., 125.24-632.45 CFU/m3) and the lowest CFU was observed in monsoon season (i.e., 20.83- 319.0 CFU/m3). The metagenomic approach with the samples collected during pre-monsoon season showed a total of bacterial 184 OTUs (operational taxonomic units) with 28,028 abundance count comprising with 7 major phylum, 6 classes, 10 orders, 15 families, 13 genus, and 8 species of bacteria. The species level distribution clearly shows the presence of Gammaproteobacteria (52%) most abundantly followed by Bacilli (21%), Alphaproteobacteria (14%), Betaproteobacteria (5%, Flavobacteria (5%), and Sphingobacteria (3%). It is the first report from entire Northeast India to uncover bacterial diversity in aerosol samples through DNA based metagenomic approach.

Differences in Fecal Microbiome and Antimicrobial Resistance between Captive and Free-Range Sika Deer under the Same Exposure of Antibiotic Anthelmintics

We used a metagenomic approach to investigate whether and how captive and free-range impact the microbial communities and antimicrobial resistance in sika deer. The results provide solid evidence of the significant impacts on the microbial composition and function in captive and free-range sika deer. Interestingly, although the sika deer had the same exposure to antibiotic anthelmintics, the antimicrobial resistances were affected by the breeding environment.

Metagenomic tracking of microbial consortia of cassava flakes (garri)

The affirmation of several cross-sectional studies on the vulnerability of cassava flakes commonly called 'garri' to microbial attack has long been documented. However, longitudinal data on metagenomic tracking of microbial consortia of this important staple food are scarce. Hence, this study was aimed at tracking the microbial consortia of garri. A total of eight samples (four each from both Nigeria and Republic of Benin markets) were randomly collected aseptically using pre-sterilized aluminum pans and processed through a metagenomic approach, while both the chemical and proximate components of garri were assessed following standard techniques. The analysis of the taxonomic consortia of garri reveals the predomination of bacteria (99.82 and 99.81% for samples from Nigeria and Republic of Benin, respectively) while the remaining sequences matched with the Archae (0.07%), fungi (0.09%) and protozoa (0.09%). A large proportion of the sequences were unclassified at the phylum level (approximately 84.10 and 86.2% for Nigerian and Beninese samples, respectively). The reads of cassava flakes metagenome of both Nigeria and Republic of Benin exhibited analogous level of average GC content with sequence count of between 187773-213444 for samples from Nigeria and 157784-198763 for samples from Republic of Benin. The functional characteristics of the inhabiting metagenomes were found containing the genes encoding for adhesins, bacteriocins, resistance to antibiotics, toxic chemicals as well as toxins and superantigens. Both the chemical and the proximate compositions of the examined garri samples, though exhibited significant disparity, but without any apparent variation in the patterns of metagenomic data. Our findings however revealed bacteria as the major contaminants of these cassava food products. Keywords; Metagenomics, Microorganisms, Cassava flakes (garri), Proximate composition

Metagenomic detection and characterisation of multiple viruses in apparently healthy Australian Neophema birds

Emerging viral pathogens are a significant concern, with potential consequences for human, animal and environmental health. Over the past several decades, many novel viruses have been found in animals, including birds, and often pose a significant threat to vulnerable species. However, despite enormous interest in virus research, little is known about virus communities (viromes) in Australian Neophema birds. Therefore, this study was designed to characterise the viromes of Neophema birds and track the evolutionary relationships of recently emerging psittacine siadenovirus F (PsSiAdV-F) circulating in the critically endangered, orange-bellied parrot (OBP, Neophema chrysogaster), using a viral metagenomic approach. This study identified 16 viruses belonging to the families Adenoviridae, Circoviridae, Endornaviridae, Picobirnaviridae and Picornaviridae. In addition, this study demonstrated a potential evolutionary relationship of a PsSiAdV-F sequenced previously from the critically endangered OBP. Strikingly, five adenoviral contigs identified in this study show the highest identities with human adenovirus 2 and human mastadenovirus C. This highlights an important and unexpected aspects of the avian virome and warrants further studies dedicated to this subject. Finally, the findings of this study emphasise the importance of testing birds used for trade or in experimental settings for potential pathogens to prevent the spread of infections.

Potential roles of 1,5-anhydro-d-fructose in modulating gut microbiome in mice

The gut microbiota has tremendous potential to affect the host’s health, in part by synthesizing vitamins and generating nutrients from food that is otherwise indigestible by the host. 1,5-Anhydro-d-fructose (1,5-AF) is a monosaccharide with a wide range of bioactive potentials, including anti-oxidant, anti-inflammatory, and anti-microbial effects. Based on its potential benefits and minimal toxicity, it is anticipated that 1,5-AF will be used as a dietary supplement to support general health. However, the effects of 1,5-AF on the gut microbiota are yet to be clarified. Here, using an unbiased metagenomic approach, we profiled the bacterial taxa and functional genes in the caecal microbiota of mice fed a diet containing either 2% 1,5-AF or a reference sweetener. Supplementation with 1,5-AF altered the composition of the gut microbiota, enriching the proportion of Faecalibacterium prausnitzii. 1,5-AF also altered the metabolomic profile of the gut microbiota, enriching genes associated with nicotinamide adenine dinucleotide biosynthesis. These findings support the potential benefits of 1,5-AF, but further studies are required to clarify the impact of 1,5-AF on health and disease.