High-Quality Draft Genome Sequences of Two Deltaproteobacterial Endosymbionts, Delta1a and Delta1b, from the Uncultured Sva0081 Clade, Assembled from Metagenomes of the Gutless Marine Worm Olavius algarvensis

Here, we present high-quality metagenome-assembled genome sequences of two closely related deltaproteobacterial endosymbionts from the gutless marine worm Olavius algarvensis (Annelida). The first is an improved draft genome sequence of the previously described sulfate-reducing symbiont Delta1. The second is from a closely related, recently discovered symbiont of O. algarvensis

High-Quality Draft Genome Sequences of the Uncultured Delta3 Endosymbiont (Deltaproteobacteria) Assembled from Metagenomes of the Gutless Marine Worm Olavius algarvensis

Here, we present two high-quality, draft metagenome-assembled genomes of deltaproteobacterial OalgDelta3 endosymbionts from the gutless marine worm Olavius algarvensis. Their 16S rRNA gene sequences share 98% identity with Delta3 endosymbionts of related host species Olavius ilvae (GenBank accession no. AJ620501) and Inanidrilus exumae (GenBank accession no. FM202060), for which no symbiont genomes are available

Fidelity varies in the symbiosis between a gutless marine worm and its microbial consortium

Background: Many animals live in intimate associations with a species-rich microbiome. A key factor in maintaining these beneficial associations is fidelity, defined as the stability of associations between hosts and their microbiota over multiple host generations. Fidelity has been well studied in terrestrial hosts, particularly insects, over longer macroevolutionary time. In contrast, little is known about fidelity in marine animals with species-rich microbiomes at short microevolutionary time scales, that is at the level of a single host population. Given that natural selection acts most directly on local populations, studies of microevolutionary partner fidelity are important for revealing the ecological and evolutionary processes that drive intimate beneficial associations within animal species. Results: In this study on the obligate symbiosis between the gutless marine annelid Olavius algarvensis and its consortium of seven co-occurring bacterial symbionts, we show that partner fidelity varies across symbiont species from strict to absent over short microevolutionary time. Using a low-coverage sequencing approach that has not yet been applied to microbial community analyses, we analysed the metagenomes of 80 O. algarvensis individuals from the Mediterranean and compared host mitochondrial and symbiont phylogenies based on single-nucleotide polymorphisms across genomes. Fidelity was highest for the two chemoautotrophic, sulphur-oxidizing symbionts that dominated the microbial consortium of all O. algarvensis individuals. In contrast, fidelity was only intermediate to absent in the sulphate-reducing and spirochaetal symbionts with lower abundance. These differences in fidelity are likely driven by both selective and stochastic forces acting on the consistency with which symbionts are vertically transmitted. Conclusions: We hypothesize that variable degrees of fidelity are advantageous for O. algarvensis by allowing the faithful transmission of their nutritionally most important symbionts and flexibility in the acquisition of other symbionts that promote ecological plasticity in the acquisition of environmental resources

Nivel de satisfacción de los usuarios del servicio de agua potable de la ciudad de Cajamarca, 2015

RESUMEN La presente investigación está referida al nivel de satisfacción de los usuarios del servicio de agua potable de la ciudad de Cajamarca, año 2015. El propósito de la presente investigación consiste en conocer el grado de nivel de satisfacción de los usuarios y elaborar propuestas para mejorar la gestión de Sistema de Agua Potable en la zona urbana para hacerle llegar a la empresa prestadora de servicios SEDACAJ. S.A. Se realizaron 384 encuestas a usuarios del servicio de agua potable, de acuerdo al tamaño muestral calculado, seleccionados aleatoriamente en la zona urbana de la ciudad, la encuesta consta de 20 preguntas divididas en dos partes con respecto al servicio y al prestador del servicio. Para medir la satisfacción de los usuarios cada pregunta fue medida por la escala de Likert: 1.muy baja 2. Baja 3.media 4.buena y 5.muy buena. Se utilizó el programa informático Microsoft Excel para el procesamiento estadístico de los datos recogidos. Los resultados arrojan que el 28.48 % de usuarios consideran que el nivel de satisfacción es muy bajo, y solo el 15.29% consideró el nivel de satisfacción muy alto, el porcentaje restante se encuentran entre baja, media y buena se evidencia claramente que los usuarios no están de acuerdo con el servicio que brinda la empresa, se recomienda que el prestador tenga en cuenta este bajo nivel de satisfacción de los usuarios y considere mejorar la calidad del servicio en base a proyectos de mejora.ABSTRACT The present investigation related to the level of user satisfaction of drinking water in the city of Cajamarca in 2015. The purpose of this research is to determine the degree of satisfaction of users and develop proposals to improve management of Water System in the urban area to let you reach the SEDACAJ company that provides services. Inc. 384 surveys were conducted to users of drinking water, according to sample size calculated, randomly selected in the urban area of the city, the survey consists of 20 questions divided into two parts with respect to the service and the service provider. To measure user satisfaction it was measured by each question Likert scale: 1. Very low 2. Low 3.media 4.buena and 5.Very good. the software Microsoft Excel for statistical processing of the data collected was used. The results show that 28.48% of users believe that the satisfaction level is very low, and only 15.29% considered the very high level of satisfaction, the remaining percentage are between low, medium and good it is clearly evident that users do not agree with the service provided by the company, it is recommended that the provider takes into account the low level of user satisfaction and consider improving the quality of service based on improvement projects

New avenues for potentially seeking microbial responses to climate change beneath Antarctic ice shelves

The signs of climate change are undeniable, and the impact of these changes on ecosystem function heavily depends on the response of microbes that underpin the food web. Antarctic ice shelf is a massive mass of floating ice that extends from the continent into the ocean, exerting a profound influence on global carbon cycles. Beneath Antarctic ice shelves, marine ice stores valuable genetic information, where marine microbial communities before the industrial revolution are archived. Here, in this proof-of-concept, by employing a combination of single-cell technologiesand metagenomics, we have been able to sequence frozen microbial DNA (≈300 years old) stored in the marine ice core B15 collected from the Filchnner-Ronne Ice Shelf. Metagenomic data indicated that Proteobacteria and Thaumarchaeota (e.g., Nitrosopumilus spp.), followed by Actinobacteria (e.g., Actinomarinales), were abundant. Remarkably, our data allow us to “travel to the past” and calibrate genomic and genetic evolutionary changes for ecologically relevant microbes and functions, such as Nitrosopumilus spp., preserved in the marine ice (≈300 years old) with those collected recently in seawater under an ice shelf (year 2017). The evolutionary divergence for the ammonia monooxygenase gene amoA involved in chemolithoautotrophy was about 0.88 amino acid and 2.8 nucleotide substitution rate per 100 sites in a century, while the accumulated rate of genomic SNPs was 2,467 per 1 Mb of genome and 100 years. Whether these evolutionary changes remained constant over the last 300 years or accelerated during post-industrial periods remains an open question that will be further elucidated.The authors thank the research grants funded by the Spanish Ministry of Science and Innovation and Agencia Estatal de Investigación (PID2021-125175OB-I00)

A critical review of the Exit-Voice-Loyalty-Neglect literature: limitations, key challenges and directions for future research

The study of human behaviour holds a prominent role in organizational behavior literature. For almost 45 years, the exit, voice, loyalty and neglect typology has attracted scholars' interest and has been linked to employee responses towards dissatisfaction and problematic events in the workplace. This paper reviews the literature and identifies and addresses key theoretical and methodological deficiencies that the exit, voice, loyalty and neglect typology faces that have been either ignored or undeveloped. Moreover, by unpicking this typology as currently portrayed in the existing literature, it proposes key challenges that need to be addressed and provides directions for future research

Horizontal acquisition of a patchwork Calvin cycle by symbiotic and free-living Campylobacterota (formerly Epsilonproteobacteria).

Assie A, Leisch N, Meier DV, et al. Horizontal acquisition of a patchwork Calvin cycle by symbiotic and free-living Campylobacterota (formerly Epsilonproteobacteria). The ISME journal. 2019;14(1):104-122.Most autotrophs use the Calvin-Benson-Bassham (CBB) cycle for carbon fixation. In contrast, all currently described autotrophs from the Campylobacterota (previously Epsilonproteobacteria) use the reductive tricarboxylic acid cycle (rTCA) instead. We discovered campylobacterotal epibionts ("Candidatus Thiobarba") of deep-sea mussels that have acquired a complete CBB cycle and may have lost most key genes of the rTCA cycle. Intriguingly, the phylogenies of campylobacterotal CBB cyclegenes suggest they were acquired in multiple transfers from Gammaproteobacteria closely related to sulfur-oxidizing endosymbionts associated with the mussels, as well as from Betaproteobacteria. We hypothesize that "Ca. Thiobarba" switched from the rTCA cycle to a fully functional CBB cycle during its evolution, by acquiring genes from multiple sources, including co-occurring symbionts. We also found key CBB cycle genes in free-living Campylobacterota, suggesting that the CBB cycle may be more widespread in this phylum than previously known. Metatranscriptomics and metaproteomics confirmed high expression of CBB cycle genes in mussel-associated "Ca. Thiobarba". Direct stable isotope fingerprinting showed that "Ca. Thiobarba" has typical CBB signatures, suggesting that it uses this cycle for carbon fixation. Our discovery calls into question current assumptions about the distribution of carbon fixation pathways in microbial lineages, and the interpretation of stable isotope measurements in the environment

Bacterial symbiont subpopulations have different roles in a deep-sea symbiosis

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Hinzke, T., Kleiner, M., Meister, M., Schlueter, R., Hentschker, C., Pane-Farre, J., Hildebrandt, P., Felbeck, H., Sievert, S. M., Bonn, F., Voelker, U., Becher, D., Schweder, T., & Markert, S. Bacterial symbiont subpopulations have different roles in a deep-sea symbiosis. Elife, 10, (2021): e58371, https://doi.org/10.7554/eLife.58371.The hydrothermal vent tubeworm Riftia pachyptila hosts a single 16S rRNA phylotype of intracellular sulfur-oxidizing symbionts, which vary considerably in cell morphology and exhibit a remarkable degree of physiological diversity and redundancy, even in the same host. To elucidate whether multiple metabolic routes are employed in the same cells or rather in distinct symbiont subpopulations, we enriched symbionts according to cell size by density gradient centrifugation. Metaproteomic analysis, microscopy, and flow cytometry strongly suggest that Riftia symbiont cells of different sizes represent metabolically dissimilar stages of a physiological differentiation process: While small symbionts actively divide and may establish cellular symbiont-host interaction, large symbionts apparently do not divide, but still replicate DNA, leading to DNA endoreduplication. Moreover, in large symbionts, carbon fixation and biomass production seem to be metabolic priorities. We propose that this division of labor between smaller and larger symbionts benefits the productivity of the symbiosis as a whole.This work was supported by the German Research Foundation DFG (grant MA 6346/2–1 to SM), fellowships of the Institute of Marine Biotechnology Greifswald (TH, MM), a German Academic Exchange Service (DAAD) grant (TH), the NC State Chancellor’s Faculty Excellence Program Cluster on Microbiomes and Complex Microbial Communities (MK), the USDA National Institute of Food and Agriculture, Hatch project 1014212 (MK), the U.S. National Science Foundation (grants OCE-1131095 and OCE-1559198 to SMS), and The WHOI Investment in Science Fund (to SMS). We furthermore acknowledge support for article processing charges from the DFG (Grant 393148499) and the Open Access Publication Fund of the University of Greifswald