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The study is conducted to show that the silver hexafluoroantimonate (AgSb[F.sub.6]) is an effective catalyst for the reactions of donor/acceptor-substituted carbenoids. The study offers a new synthetic opportunity, which cannot be achieved with dirhodium catalysis.

Planktothricoides is a free-living filamentous cyanobacterium belonging to the order Oscillatoriales and the family Phormidiaceae, capable of forming bloom in fresh and brackish waters. A unicyanobacterial non-axenic culture dominated by Planktothricoides sp. SR001 was obtained from a freshwater reservoir in Singapore. The draft genome presented here is the first tropical freshwater Planktothricoides sp. ever sequenced. The genome of 7.0Mbp contains 5,776 genes predicted using the JGI IMG pipeline. The whole genome sequence allows identification of genes encoding for nitrogen-fixation, accessory photosynthetic pigments and biosynthesis of an off-flavor compound, 2- methylisoborneol, which has been experimentally verified here based on metabolite detection. In addition, strain SR001 genome contains an operon putatively involved in the production of a linear tripeptide cyanobactin related to viridisamide A and aeruginosamide, with the later known to possess anti-microbial or cytotoxic effect. [ABSTRACT FROM AUTHOR]

A non-axenic unialgal culture containing a Subsection V (Stigonematales) cyanobacterium, Hapalosiphon strain MRB 220, was obtained from a benthic freshwater algal mat through multiple transfers following growth in sterile media. Physiological characterization demonstrated the culture was capable of nitrogen-fixation and production of the off flavor compound 2-methylisoborneol (2-MIB). Total DNA isolated from this culture was sequenced using Illumina HiSeq and de novo assembled into contigs. The genome of MRB 220 was separated from co-occurring heterotrophic bacteria using sequence homology and compositional approaches, and its purity was confirmed based on best BLAST hit classification and principle component analysis of the tetranucleotide frequencies of fragmented contigs. The genome of ~7.4 Mbp contains 6,345 protein coding genes with 4,320 of these having functional prediction including predicted pathways for biosynthesis of the secondary metabolite welwitindolinone. Analyses of 16S rRNA gene and whole genome sequence average nucleotide identity indicated close relatedness of MRB 220 to the genera Hapalosiphon and Fischerella within the order Stigonematales. Microscopic examination showed that MRB 220 formed heterocystous branched filaments, thereby supporting identification of strain MRB 220 as a morphospecies of Hapalosiphon. Availability of the draft genome of Hapalosiphon strain MRB 220 enables future work to elucidate the pathway and dynamics for biosynthesis of 2-MIB and other secondary metabolites and understand the ecology and physiology of Stigonematales cyanobacteria in tropical freshwaters. [ABSTRACT FROM AUTHOR]

It has been proposed that the chemical composition of a coral's mucus can influence the associated bacterial community. However, information on this topic is rare, and nonexistent for corals that are under thermal stress. This study therefore compared the carbohydrate composition of mucus in the coral Acropora muricata when subjected to increasing thermal stress from 26 to 31°C, and determined whether this composition correlated with any changes in the bacterial community. Results showed that, at lower temperatures, the main components of mucus were N-acetyl glucosamine and C6 sugars, but these constituted a significantly lower proportion of the mucus in thermally stressed corals. The change in the mucus composition coincided with a shift from a g- Proteobacteria- to a Verrucomicrobiae- and α-Proteobacteria-dominated community in the coral mucus. Bacteria in the class Cyanobacteria also started to become prominent in the mucus when the coral was thermally stressed. The increase in the relative abundance of the Verrucomicrobiae at higher temperature was strongly associated with a change in the proportion of fucose, glucose, and mannose in the mucus. Increase in the relative abundance of α-Proteobacteria were associated with GalNAc and glucose, while the drop in relative abundance of γ-Proteobacteria at high temperature coincided with changes in fucose and mannose. Cyanobacteria were highly associated with arabinose and xylose. Changes in mucus composition and the bacterial community in the mucus layer occurred at 29°C, which were prior to visual signs of coral bleaching at 31°C. A compositional change in the coral mucus, induced by thermal stress could therefore be a key factor leading to a shift in the associated bacterial community. This, in turn, has the potential to impact the physiological function of the coral holobiont. [ABSTRACT FROM AUTHOR]

Water quality is an emergent property of a complex system comprised of interacting microbial populations and introduced microbial and chemical contaminants. Studies leveraging next-generation sequencing (NGS) technologies are providing new insights into the ecology of microbially mediated processes that influence fresh water quality such as algal blooms, contaminant biodegradation, and pathogen dissemination. In addition, sequencing methods targeting small subunit (SSU) rRNA hypervariable regions have allowed identification of signature microbial species that serve as bioindicators for sewage contamination in these environments. Beyond amplicon sequencing, metagenomic and metatranscriptomic analyses of microbial communities in fresh water environments reveal the genetic capabilities and interplay of waterborne microorganisms, shedding light on the mechanisms for production and biodegradation of toxins and other contaminants. This review discusses the challenges and benefits of applying NGS-based methods to water quality research and assessment. We will consider the suitability and biases inherent in the application of NGS as a screening tool for assessment of biological risks and discuss the potential and limitations for direct quantitative interpretation of NGS data. Secondly, we will examine case studies from recent literature where NGS based methods have been applied to topics in water quality assessment, including development of bioindicators for sewage pollution and microbial source tracking, characterizing the distribution of toxin and antibiotic resistance genes in water samples, and investigating mechanisms of biodegradation of harmful pollutants that threaten water quality. Finally, we provide a short review of emerging NGS platforms and their potential applications to the next generation of water quality assessment tools. [ABSTRACT FROM AUTHOR]

We have characterized the molecular and genomic diversity of the microbiota of the starlet sea anemone Nematostella vectensis, a cnidarian model for comparative developmental and functional biology and a year-round inhabitant of temperate salt marshes. Molecular phylogenetic analysis of 16S rRNA gene clone libraries revealed four ribotypes associated with N. vectensis at multiple locations and times. These associates include two novel ribotypes within the e-Proteobacterial order Campylobacterales and the Spirochetes, respectively, each sharing <85% identity with cultivated strains, and two -Proteobacterial ribotypes sharing >99% 16S rRNA identity with Endozoicomonas elysicola and Pseudomonas oleovorans, respectively. Species-specific PCR revealed that these populations persisted in N. vectensis asexually propagated under laboratory conditions. cDNA indicated expression of the Campylobacterales and Endozoicomonas 16S rRNA in anemones from Sippewissett Marsh, MA. A collection of bacteria from laboratory raised N. vectensis was dominated by isolates from P. oleovorans and Rhizobium radiobacter. Isolates from field-collected anemones revealed an association with Limnobacter and Stappia isolates. Genomic DNA sequencing was carried out on 10 cultured bacterial isolates representing field- and laboratory-associates, i.e., Limnobacter spp., Stappia spp., P. oleovorans and R. radiobacter. Genomes contained multiple genes identified as virulence (host-association) factors while S. stellulata and L. thiooxidans genomes revealed pathways for mixotrophic sulfur oxidation. A pilot metatranscriptome of laboratory-raised N. vectensis was compared to the isolate genomes and indicated expression of ORFs from L. thiooxidans with predicted functions of motility, nutrient scavenging (Fe and P), polyhydroxyalkanoate synthesis for carbon storage, and selective permeability (porins). We hypothesize that such activities may mediate acclimation and persistence of bacteria in a N. vectensis holobiont defined by both internal and external gradients of chemicals and nutrients in a dynamic coastal habitat. [ABSTRACT FROM AUTHOR]

The article focuses on exploitation within the U.S. organ donation and egg donation schemes in 2013. Topics include why female egg donation is allowed under U.S. organ donation laws, compensation for organ donation, and why the two different types of donation are treated differently by the U.S. legislature. Information is provided on the U.S. National Organ Transplant Act of 1984 (NOTA).

The article focuses on a study which examined correlations between shrimp pathogenicity in Vibrio (V.) harveyi isolated from Thailand, hemolysis, hemolysin genes and vcrD, a gene involved in the type III secretion system (TTSS) of V. harveyi. TTSS, described as a bacterial system that transfers effector virulence proteins across the membrane of the bacterial pathogen into the cytoplasm of the host cell, can be found in many Gram-negative bacteria. Through random amplified polymorphic DNA (RAPD) analysis, researchers found a high degree of genetic diversity in all the V. harveyi isolates.

• Most ethics- and rights-based frameworks lack enforceability for regulating WWS. • Obligations (shaped by ethics and rights) can bind behaviour across society. • Obligations can be codified as laws that can govern the implementation of WWS. • These laws can be transparent, limit power, and grant institutional oversight. • WWS obligations can also include non-legislative enforcement means (e.g. courts). As the threat of COVID-19 recedes, wastewater surveillance – unlike other pandemic-era public health surveillance methods – seems here to stay. Concerns have been raised, however, about the potential risks that wastewater surveillance might pose towards group privacy. Existing scholarship has focused upon using ethics- or human rights-based frameworks as a means of balancing the public health objectives of wastewater surveillance and the potential risks it might pose to group privacy. However, such frameworks greatly lack enforceability. In order to further the strong foundation laid by such frameworks – while addressing their lack of enforceability – this paper proposes the idea of the 'obligation' as an alternative way to regulate wastewater surveillance systems. The legal codification of said obligations provides a method of ensuring that wastewater surveillance systems can be deployed effectively and equitably. Our paper proposes that legal obligations for wastewater surveillance can be created and enforced through transparent and purposeful legislation (which would include limits on power and grant institutions substantial oversight) as well as paying heed to non-legislative legal means of enforcement, such as through courts or contracts. Introducing legal obligations for wastewater surveillance could therefore be highly useful to researchers, policymakers, corporate technologists, and government agencies working in this field. [Display omitted] [ABSTRACT FROM AUTHOR]

This study addressed whether digital droplet PCR (ddPCR) could improve sensitivity and specificity of human-associated Bacteroidales genetic markers, BacHum and B. theta, and their quantification in environmental and fecal composite samples. Human markers were quantified by qPCR and ddPCR platforms obtained from the same manufacturer. A total of 180 samples were evaluated by each platform including human and animal feces, sewage, and environmental water. The sensitivity of ddPCR and qPCR marker assays in sewage and human stool was 0.85–1.00 with marginal reduction in human stool by ddPCR relative to qPCR (<10%). The prevalence and distribution of markers across complex sample types was similar (74–100% agreement) by both platforms with qPCR showing higher sensitivity for markers in environmental and composite samples and ddPCR showing greater reproducibility for marker detection in fecal composites. Determination of BacHum prevalence in fecal samples by ddPCR increased specificity relative to qPCR (from 0.58 to 0.88) and accuracy (from 0.77 to 0.94), while the B. theta assay performed similarly on both platforms (specificity = 0.98). In silico analysis indicated higher specificity of ddPCR for BacHum was not solely attributed to reduced sensitivity relative to qPCR. Marker concentrations measured by ddPCR for all sample types were consistently lower than those measured by qPCR, by a factor of 2.6 ± 2.8 for B. theta and 18.7 ± 10.0 for BacHum. We suggest that differences in assay performance on ddPCR and qPCR platforms may be linked to the characteristics of the assay targets (that is, genes with multiple versus single copies and encoding proteins versus ribosomal RNA) however further work is needed to validate these ideas. We conclude that ddPCR is a suitable tool for microbial source tracking, however, other factors such as cost-effectiveness and assay-specific performance should be considered. Image 1 • Digital droplet (dd) PCR was validated for Bacteroidales -based microbial source tracking. • Sensitivity of quantitative (q) PCR for Bacteroidales human markers in feces was superior to ddPCR. • Assay specificity and reproducibility in feces by ddPCR were greater than or nearly equal to those by qPCR. • qPCR and ddPCR platform performance may vary with assay. [ABSTRACT FROM AUTHOR]

[Display omitted] • Based on historical reports, shedding of vaccine-derived genetic materials was only detected with replication-competent vaccines. • None of the WHO-approved COVID-19 vaccines pose a risk of a false positive signal for wastewater-based surveillance (WBS). • The relationship between wastewater and clinical data changes throughout the pandemic. • Comparison of WBS signals across longer timescales is complicated by vaccination and prevailing variant of concern. SARS-CoV-2 wastewater-based surveillance (WBS) offers a tool for cost-effective oversight of a population's infections. In the past two years, WBS has proven to be crucial for managing the pandemic across different geographical regions. However, the changing context of the pandemic due to high levels of COVID-19 vaccination warrants a closer examination of its implication towards SARS-CoV-2 WBS. Two main questions were raised: 1) Does vaccination cause shedding of viral signatures without infection? 2) Does vaccination affect the relationship between wastewater and clinical data? To answer, we review historical reports of shedding from viral vaccines in use prior to the COVID-19 pandemic including for polio, rotavirus, influenza and measles infection and provide a perspective on the implications of different COVID-19 vaccination strategies with regard to the potential shedding of viral signatures into the sewershed. Additionally, we reviewed studies that looked into the relationship between wastewater and clinical data and how vaccination campaigns could have affected the relationship. Finally, analyzing wastewater and clinical data from the Netherlands, we observed changes in the relationship concomitant with increasing vaccination coverage and switches in dominant variants of concern. First, that no vaccine-derived shedding is expected from the current commercial pipeline of COVID-19 vaccines that may confound interpretation of WBS data. Secondly, that breakthrough infections from vaccinated individuals contribute significantly to wastewater signals and must be interpreted in light of the changing dynamics of shedding from new variants of concern. [ABSTRACT FROM AUTHOR]

• Gaps exist in current modes of arboviral disease surveillance. • Arboviruses are shed in urine of infected individuals. • Wastewater-based surveillance may be utilized for monitoring arboviral diseases. • Successful implementation warrants development of methods optimized for arboviruses. Arboviral diseases are caused by a group of viruses spread by the bite of infected arthropods. Amongst these, dengue, Zika, west nile fever and yellow fever cause the greatest economic and social impact. Arboviral epidemics have increased in frequency, magnitude and geographical extent over the past decades and are expected to continue increasing with climate change and expanding urbanisation. Arboviral prevalence is largely underestimated, as most infections are asymptomatic, nevertheless existing surveillance systems are based on passive reporting of loosely defined clinical syndromes with infrequent laboratory confirmation. Wastewater-based surveillance (WBS), which has been demonstrated to be useful for monitoring diseases with significant asymptomatic populations including COVID19 and polio, could be a useful complement to arboviral surveillance. We review the current state of knowledge and identify key factors that affect the feasibility of monitoring arboviral diseases by WBS to include viral shedding loads by infected persons, the persistence of shed arboviruses and the efficiency of their recovery from sewage. We provide a simple model on the volume of wastewater that needs to be processed for detection of arboviruses, in face of lower arboviral shedding rates. In all, this review serves to reflect on the key challenges that need to be addressed and overcome for successful implementation of arboviral WBS. Wastewater-based surveillance as a complement to clinical surveillance for collective monitoring of symptomatic and asymptomatic infections. Arboviruses have a complex transmission cycle consisting of a sylvatic cycle where they circulate between animals and mosquitoes, and a human cycle where they circulate between humans and mosquitoes. Clinical surveillance is the main pillar of arboviral surveillance, however it is mostly made up of symptomatic cases which seek medical attention, and those who are subsequently accurately diagnosed to carry arboviral infections. Wastewater is an aggregate collection of all individuals within the catchment, potentially sampling both symptomatic and asymptomatic populations, and WBS would be a useful complement for arboviral disease surveillance. While arboviral RNA is detected in the urine of individuals with mild to severe forms of the diseases, there is limited data on the magnitude of viral shedding from asymptomatic individuals (indicated with a dashed line). [Display omitted] [ABSTRACT FROM AUTHOR]

Growth of microorganisms in environments containing CO2 above its critical point is unexpected due to a combination of deleterious effects, including cytoplasmic acidification and membrane destabilization. Thus, supercritical CO2 (scCO2) is generally regarded as a sterilizing agent. We report isolation of bacteria from three sites targeted for geologic carbon dioxide sequestration (GCS) that are capable of growth in pressurized bioreactors containing scCO2. Analysis of 16S rRNA genes from scCO2 enrichment cultures revealed microbial assemblages of varied complexity, including representatives of the genus Bacillus. Propagation of enrichment cultures under scCO2 headspace led to isolation of six strains corresponding to Bacillus cereus, Bacillus subterraneus, Bacillus amyloliquefaciens, Bacillus safensis, and Bacillus megaterium. Isolates are spore-forming, facultative anaerobes and capable of germination and growth under an scCO2 headspace. In addition to these isolates, several Bacillus type strains grew under scCO2, suggesting that this may be a shared feature of spore-forming Bacillus spp. Our results provide direct evidence of microbial activity at the interface between scCO2 and an aqueous phase. Since microbial activity can influence the key mechanisms for permanent storage of sequestered CO2 (i.e., structural, residual, solubility, and mineral trapping), our work suggests that during GCS microorganisms may grow and catalyze biological reactions that influence the fate and transport of CO2 in the deep subsurface. [ABSTRACT FROM AUTHOR]