Emerging RNA virus infections are a growing concern among domestic poultry industries due to the severe impact they can have on flock health and economic livelihoods. Avian paramyxoviruses (APMV; avulaviruses, AaV) are pathogenic, negative-sense RNA viruses that cause serious infections in the respiratory and central nervous systems. APMV was detected in multiple avian species during the 2017 wild bird migration season in Ukraine and studied using PCR, virus isolation, and sequencing. Of 4090 wild bird samples collected, mostly from southern Ukraine, eleven isolates were grown in ovo and identified for APMV serotype by hemagglutinin inhibition test as: APMV-1, APMV-4, APMV-6, and APMV-7. To build One Health’s capacity to characterize APMV virulence and analyze the potential risks of spillover to immunologically naïve populations, we sequenced virus genomes in veterinary research labs in Ukraine using a nanopore (MinION) platform. RNA was extracted and amplified using a multiplex tiling primer approach to specifically capture full-length APMV-1 (n = 5) and APMV-6 (n = 2) genomes at high read depth. All APMV-1 and APMV-6 fusion (F) proteins possessed a monobasic cleavage site, suggesting these APMVs were likely low virulence, annually circulating strains. Utilization of this low-cost method will identify gaps in viral evolution and circulation in this understudied but important critical region for Eurasia.
The complete genome of Salmonella enterica subsp. enterica serovar Kottbus (serogroup C2-C3), which was isolated from a commercial pork production facility in Kharkiv, Ukraine, was assembled using long-read Nanopore sequences. A single circular contig (4,799,045 bp) comprised a complete chromosome encoding antibiotic resistance, highlighting the risk of cross-species livestock and human infection.
Abstract Background Riverine ecosystems are biogeochemical powerhouses driven largely by microbial communities that inhabit water columns and sediments. Because rivers are used extensively for anthropogenic purposes (drinking water, recreation, agriculture, and industry), it is essential to understand how these activities affect the composition of river microbial consortia. Recent studies have shown that river metagenomes vary considerably, suggesting that microbial community data should be included in broad-scale river ecosystem models. But such ecogenomic studies have not been applied on a broad “aquascape” scale, and few if any have applied the newest nanopore technology. Results We investigated the metagenomes of 11 rivers across 3 continents using MinION nanopore sequencing, a portable platform that could be useful for future global river monitoring. Up to 10 Gb of data per run were generated with average read lengths of 3.4 kb. Diversity and diagnosis of river function potential was accomplished with 0.5–1.0 ⋅ 106 long reads. Our observations for 7 of the 11 rivers conformed to other river-omic findings, and we exposed previously unrecognized microbial biodiversity in the other 4 rivers. Conclusions Deeper understanding that emerged is that river microbial consortia and the ecological functions they fulfil did not align with geographic location but instead implicated ecological responses of microbes to urban and other anthropogenic effects, and that changes in taxa manifested over a very short geographic space.
The three presently known enzymes responsible for arsenic-using bioenergetic processes are arsenite oxidase (Aio), arsenate reductase (Arr) and alternative arsenite oxidase (Arx), all of which are molybdoenzymes from the vast group referred to as the Mo/W-bisPGD enzyme superfamily. Since arsenite is present in substantial amounts in hydrothermal environments, frequently considered as vestiges of primordial biochemistry, arsenite-based bioenergetics has long been predicted to be ancient. Conflicting scenarios, however, have been put forward proposing either Arr/Arx or Aio as operating in the ancestral metabolism. Phylogenetic data argue in favor of Aio whereas biochemical and physiological data led several authors to propose Arx/Arr as the most ancient anaerobic arsenite metabolizing enzymes. Here we combine phylogenetic approaches with physiological and biochemical experiments to demonstrate that the Arx/Arr enzymes could not have been functional in the Archaean geological eon. We propose that Arr reacts with menaquinones to reduce arsenate whereas Arx reacts with ubiquinone to oxidize arsenite, in line with thermodynamic considerations. The distribution of the quinone biosynthesis pathways, however, clearly indicates that the ubiquinone pathway is recent. An updated phylogeny of Arx furthermore reinforces the hypothesis of a recent emergence of this enzyme. We therefore conclude that anaerobic arsenite redox conversion in the Archaean must have been performed in a metabolism involving Aio.
In this report, we describe the complete genome assembly of a Pantoea agglomerans isolate, TH81, collected from a boreal forest soil associated with permafrost thaw. Using both Nanopore and Illumina sequences, we assembled four circular contigs totaling 4,983,504 bp (N-50, 4,127,869 bp), a complete chromosome with three plasmids.
Experiential learning in the field is an opportunity for students to enter the heart of a scientific discipline. Through such experience, they can extract conceptual clues and discover motivational stepping stones that will potentially influence the rest of their education and career choice. Unfortunately, in Biology, the inescapable topic of Next-Generation Sequencing represents a challenge when it comes to create an educational curriculum that aims to provide students with hands-on experience on sequencers. It is an even more difficult task to accomplish if one’s purpose was to set such curriculum in a field situation. However, in recent years, educators have seen possibility to bring Next-Generation Sequencing to the reach of students more easily, with the Oxford Nanopore MinION, a low-budget, user-friendly, hand-held sequencer. Academic researchers have illustrated the performances of this device in the field and are inspirational for curricula aiming to take the next generation of scientists in the outdoors. We designed a modular 5-day workshop, with nanopore sequencing to be performed in field conditions. Here we describe the material and methods that lead the students and instructors from sample collection, DNA extraction and preparation for nanopore sequencing with MinION to real-time analysis of the data collected. This curriculum was implemented for the first-time aboard Research Vessel Sikuliaq during a transit organized by the STEMSEAS program at Columbia University in collaboration with the University of Alaska BLaST program. The line of investigation formulated for the workshop was an open-ended question that led the students to establish a proof of concept in terms of technology deployment at sea: what will show metagenomic results from DNA obtained from sea water and sequenced with Oxford Nanopore MinION? The workshop took place in October 2018 while Research Vessel Sikuliaq sailed the Alaskans seas for 7 days. Students successfully used nanopore sequencing for multiple metagenomic seawater samples. Their introductory analysis was consistent with environmental conditions and they were able to present their results by the end of the workshop.
Here, we report the complete genome sequence of an African swine fever (ASF) virus (ASFV/Kyiv/2016/131) isolated from the spleen of a domestic pig in Ukraine with a lethal case of African swine fever. Using only long-read Nanopore sequences, we assembled a full-length genome of 191,911 base pairs in a single contig.
Newly released Rapid Low Input by PCR Barcoding Sequencing Kit (SQK-RLB001); minor adjustments indicated by (*).
The Mesomycetozoea branch near the animal-fungal divergence and are believed to be important to understanding the origins of multicellularity. In 2012, a free-living saprotrophic mesomycetozoean was isolated from the sub-Arctic Bering Sea. A hybrid assembly using Illumina and Nanopore sequences yielded 2,688 contigs with a total length of 125,635,304 bases.
Fungi are important parasites of primary producers and nutrient cyclers in aquatic ecosystems. In the Pacific-Arctic domain, fungal parasitism is linked to light intensities and algal stress that can elevate disease incidence on algae and reduce diatom concentrations. Fungi are vastly understudied in the marine realm and knowledge of their function is constrained by the current understanding of fungal distribution and drivers on global scales. To investigate the spatial distribution of fungi in the western Arctic and sub-Arctic, we used high throughput methods to sequence 18S rRNA, cloned and sequenced 28S rRNA and microscopically counted chytrid-infected diatoms. We identified a broad distribution of fungal taxa predominated by Chytridiomycota and Dikarya. Phylogenetic analysis of our Chytridiomycota clones placed Arctic marine fungi sister to the order Lobulomycetales. This clade of fungi predominated in fungal communities under ice with low snowpack. Microscopic examination of fixed seawater and sea ice samples revealed chytrids parasitizing diatoms collected across the Arctic that notably infected 25% of a single diatom species in the Bering Sea. The Pezizomycotina comprised > 95% of eukaryotic sequence reads in Greenland, providing preliminary evidence for osmotrophs being a substitute for algae as the base of food webs.
Heme proteins are almost ubiquitous both in Archaea and in Bacteria. The last universal common ancestor (LUCA) of the two prokaryotic domains was, therefore, assumed until recently to already have made use of heme cofactors, a notion bolstered by molecular phylogenies of several heme-bearing enzymes. The discovery of a second pathway for heme biosynthesis, predominantly present in Archaea, was subsequently interpreted to indicate independent origins of heme biosynthesis in each of the two prokaryotic domains (Lane and Martin (Cell 151: 1406-1416, 2012)), implying that the LUCA might have been entirely devoid of hemes and heme proteins. In this contribution, we outline the presently available evidence in favour of either scenario and propose a new model reconciling the seemingly contradictory messages sent by molecular phylogeny of heme-bearing enzymes and the biosynthesis pathway dichotomy. A possible relation to other biosynthesis pathway dichotomies is suggested, and the far-reaching repercussions of the ultimate resolution of the controversy on our understanding of free energy conversion in the LUCA and at life's origin are emphasized.
Gene deletion and protein expression are cornerstone procedures for studying metabolism in any organism, including methane-producing archaea (methanogens). Methanogens produce coenzymes and cofactors not found in most bacteria, therefore it is sometimes necessary to express and purify methanogen proteins from the natural host. Protein expression in the native organism is also useful when studying post-translational modifications and their effect on gene expression or enzyme activity. We have created several new suicide plasmids to complement existing genetic tools for use in the methanogen, Methanosarcina acetivorans. The new plasmids are derived from the commercially available Escherichia coli plasmid, pNEB193, and cannot replicate autonomously in methanogens. The designed plasmids facilitate markerless gene deletion, gene transcription, protein expression, and purification of proteins with cleavable affinity tags from the methanogen, M. acetivorans.
The ubiquitous ATP synthase uses an electrochemical gradient to synthesize cellular energy in the form of ATP. The production of this electrochemical gradient relies on liposoluble proton carriers like ubiquinone (UQ), which is used in the respiratory chains of eukaryotes and proteobacteria. The biosynthesis of UQ requires three hydroxylation reactions on contiguous positions of an aromatic ring. In Escherichia coli, each of three UQ flavin monooxygenases (FMOs), called UbiF, UbiH, and UbiI, modifies a single position of the aromatic ring. This pattern of three hydroxylation reactions/three proteins has been accepted as a paradigm in UQ biology. Using a phylogenetic analysis, we found that UbiF, UbiH, and UbiI are detected only in a small fraction of proteobacteria, and we identified two new types of UQ FMOs: UbiM, which is distributed in members of the alpha, beta, and gamma classes of proteobacteria, and UbiL, which is restricted to members of the alphaproteobacteria. Remarkably, the ubiL and ubiM genes were found in genomes with fewer than three UQ hydroxylase-encoding genes. We demonstrated, using biochemical approaches, that UbiL from Rhodospirillum rubrum and UbiM from Neisseria meningitidis hydroxylate, respectively, two and three positions of the aromatic ring during UQ biosynthesis. We conclude that bacteria have evolved a large repertoire of hydroxylase combinations for UQ biosynthesis, including pathways with either three specialist enzymes or pathways with one or two generalist enzymes of broader regioselectivity. The emergence of the latter is potentially related to genome reduction events.IMPORTANCE UQ, a key molecule for cellular bioenergetics that is conserved from proteobacteria to humans, appeared in an ancestral proteobacterium more than 2 billion years ago. UQ biosynthesis has been studied only in a few model organisms, and thus, the diversity of UQ biosynthesis pathways is largely unknown. In the work reported here, we conducted a phylogenomic analysis of hydroxylases involved in UQ biosynthesis. Our results support the existence of at least two UQ hydroxylases in the proteobacterial ancestor, and yet, we show that their number varies from one to four in extant proteobacterial species. Our biochemical experiments demonstrated that bacteria containing only one or two UQ hydroxylases have developed generalist enzymes that are able to catalyze several steps of UQ biosynthesis. Our study documents a rare case where evolution favored the broadening of an enzyme's regioselectivity, which resulted in gene loss in several proteobacterial species with small genomes.
Ocean Sampling Day was initiated by the EU-funded Micro B3 (Marine Microbial Biodiversity, Bioinformatics, Biotechnology) project to obtain a snapshot of the marine microbial biodiversity and function of the world's oceans. It is a simultaneous global mega-sequencing campaign aiming to generate the largest standardized microbial data set in a single day. This will be achievable only through the coordinated efforts of an Ocean Sampling Day Consortium, supportive partnerships and networks between sites. This commentary outlines the establishment, function and aims of the Consortium and describes our vision for a sustainable study of marine microbial communities and their embedded functional traits.
Living entities are unimaginable without means to harvest free energy from the environment, that is, without bioenergetics. The quest to understand the bioenergetic ways of early life therefore is one of the crucial elements to understand the emergence of life on our planet. Over the last few years, several mutually exclusive scenarios for primordial bioenergetics have been put forward, all of which are based on some sort of empirical observation, a remarkable step forward from the previous, essentially untestable, ab initio models. We here try to present and compare these scenarios while at the same time discuss their respective empirical weaknesses. The goal of this article is to harness crucial new expertise from the entire field by stimulating a larger part of the bioenergetics community to become involved in "origin-of-energy-metabolism" research. This article is part of a Special Issue entitled: 18th European Bioenergetic Conference.
Living entities are unimaginable without means to harvest free energy from the environment, that is, without bioenergetics. The quest to understand the bioenergetic ways of early life therefore is one of the crucial elements to understand the emergence of life on our planet. Over the last few years, several mutually exclusive scenarios for primordial bioenergetics have been put forward, all of which are based on some sort of empirical observation, a remarkable step forward from the previous, essentially untestable, ab initio models. We here try to present and compare these scenarios while at the same time discuss their respective empirical weaknesses. The goal of this article is to harness crucial new expertise from the entire field by stimulating a larger part of the bioenergetics community to become involved in “origin-of-energy-metabolism” research. This article is part of a Special Issue entitled: 18th European Bioenergetic Conference.
Complex life on our planet crucially depends on strong redox disequilibria afforded by the almost ubiquitous presence of highly oxidizing molecular oxygen. However, the history of O 2 -levels in the atmosphere is complex and prior to the Great Oxidation Event some 2.3 billion years ago, the amount of O 2 in the biosphere is considered to have been extremely low as compared with present-day values. Therefore the evolutionary histories of life and of O 2 -levels are likely intricately intertwined. The obvious biological proxy for inferring the impact of changing O 2 -levels on life is the evolutionary history of the enzyme allowing organisms to tap into the redox power of molecular oxygen, i.e. the bioenergetic O 2 reductases, alias the cytochrome and quinol oxidases. Consequently, molecular phylogenies reconstructed for this enzyme superfamily have been exploited over the last two decades in attempts to elucidate the interlocking between O 2 levels in the environment and the evolution of respiratory bioenergetic processes. Although based on strictly identical datasets, these phylogenetic approaches have led to diametrically opposite scenarios with respect to the history of both the enzyme superfamily and molecular oxygen on the Earth. In an effort to overcome the deadlock of molecular phylogeny, we here review presently available structural, functional, palaeogeochemical and thermodynamic information pertinent to the evolution of the superfamily (which notably also encompasses the subfamily of nitric oxide reductases). The scenario which, in our eyes, most closely fits the ensemble of these non-phylogenetic data, sees the low O 2 -affinity SoxM- (or A-) type enzymes as the most recent evolutionary innovation and the high-affinity O 2 reductases (SoxB or B and cbb 3 or C) as arising independently from NO-reducing precursor enzymes.