scholarly journals Metagenomic and Metatranscriptomic Analyses Reveal the Structure and Dynamics of a Dechlorinating Community Containing Dehalococcoides mccartyi and Corrinoid-Providing Microorganisms under Cobalamin-Limited Conditions

2017 ◽  
Vol 83 (8) ◽  
Author(s):  
Yujie Men ◽  
Ke Yu ◽  
Jacob Bælum ◽  
Ying Gao ◽  
Julien Tremblay ◽  
...  
Keyword(s):  
De Novo ◽  
Early Stage ◽  
Microbial Interactions ◽  
Community Members ◽  
Content Type ◽  
Dehalococcoides Mccartyi ◽  
Level Information ◽  
Microbe Interactions ◽  
The One ◽  
Shed Light

ABSTRACT The aim of this study is to obtain a systems-level understanding of the interactions between Dehalococcoides and corrinoid-supplying microorganisms by analyzing community structures and functional compositions, activities, and dynamics in trichloroethene (TCE)-dechlorinating enrichments. Metagenomes and metatranscriptomes of the dechlorinating enrichments with and without exogenous cobalamin were compared. Seven putative draft genomes were binned from the metagenomes. At an early stage (2 days), more transcripts of genes in the Veillonellaceae bin-genome were detected in the metatranscriptome of the enrichment without exogenous cobalamin than in the one with the addition of cobalamin. Among these genes, sporulation-related genes exhibited the highest differential expression when cobalamin was not added, suggesting a possible release route of corrinoids from corrinoid producers. Other differentially expressed genes include those involved in energy conservation and nutrient transport (including cobalt transport). The most highly expressed corrinoid de novo biosynthesis pathway was also assigned to the Veillonellaceae bin-genome. Targeted quantitative PCR (qPCR) analyses confirmed higher transcript abundances of those corrinoid biosynthesis genes in the enrichment without exogenous cobalamin than in the enrichment with cobalamin. Furthermore, the corrinoid salvaging and modification pathway of Dehalococcoides was upregulated in response to the cobalamin stress. This study provides important insights into the microbial interactions and roles played by members of dechlorinating communities under cobalamin-limited conditions. IMPORTANCE The key chloroethene-dechlorinating bacterium Dehalococcoides mccartyi is a cobalamin auxotroph, thus acquiring corrinoids from other community members. Therefore, it is important to investigate the microbe-microbe interactions between Dehalococcoides and the corrinoid-providing microorganisms in a community. This study provides systems-level information, i.e., taxonomic and functional compositions and dynamics of the supportive microorganisms in dechlorinating communities under different cobalamin conditions. The findings shed light on the important roles of Veillonellaceae species in the communities compared to other coexisting community members in producing and providing corrinoids for Dehalococcoides species under cobalamin-limited conditions.

scholarly journals Sustainable Growth of Dehalococcoides mccartyi 195 by Corrinoid Salvaging and Remodeling in Defined Lactate-Fermenting Consortia

2014 ◽  
Vol 80 (7) ◽  
pp. 2133-2141 ◽  
Author(s):  
Yujie Men ◽  
Erica C. Seth ◽  
Shan Yi ◽  
Robert H. Allen ◽  
Michiko E. Taga ◽  
...  
Keyword(s):  
Cell Growth ◽  
Abc Transporter ◽  
De Novo ◽  
Sustainable Growth ◽  
Desulfovibrio Vulgaris ◽  
Physiological Level ◽  
Content Type ◽  
Dehalococcoides Mccartyi ◽  
Microbe Interactions ◽  
Abc Transporter Genes

ABSTRACTCorrinoids are essential cofactors of reductive dehalogenases inDehalococcoides mccartyi, an important bacterium in bioremediation, yet sequencedD. mccartyistrains do not possess the complete pathway forde novocorrinoid biosynthesis.Pelosinussp. andDesulfovibriosp. have been detected in dechlorinating communities enriched from contaminated groundwater without exogenous cobalamin corrinoid. To investigate the corrinoid-related interactions among key members of these communities, we constructed consortia by growingD. mccartyistrain 195 (Dhc195) in cobalamin-free, trichloroethene (TCE)- and lactate-amended medium in cocultures withDesulfovibrio vulgarisHildenborough (DvH) orPelosinus fermentansR7 (PfR7) and with both in tricultures. Only the triculture exhibited sustainable dechlorination and cell growth when a physiological level of 5,6-dimethylbenzimidazole (DMB), the lower ligand of cobalamin, was provided. In the triculture, DvH provided hydrogen while PfR7 provided corrinoids to Dhc195, and the initiation of dechlorination and Dhc195 cell growth was highly dependent on the growth of PfR7. Corrinoid analysis indicated that Dhc195 imported and remodeled the phenolic corrinoids produced by PfR7 into cobalamin in the presence of DMB. Transcriptomic analyses of Dhc195 showed the induction of the CbiZ-dependent corrinoid-remodeling pathway and BtuFCD corrinoid ABC transporter genes during corrinoid salvaging and remodeling. In contrast, another operon annotated to encode a putative iron/cobalamin ABC transporter (DET1174-DET1176) was induced when cobalamin was exogenously provided. Interestingly, a global upregulation of phage-related genes was observed when PfR7 was present. These findings provide insights into both the gene regulation of corrinoid salvaging and remodeling in Dhc195 when it is grown without exogenous cobalamin and microbe-to-microbe interactions in dechlorinating microbial communities.

scholarly journals Spatial metabolomics of in situ, host-microbe interactions

2019 ◽  
Author(s):  
Benedikt K Geier ◽  
Emilia Sogin ◽  
Dolma Michellod ◽  
Moritz Janda ◽  
Mario Kompauer ◽  
...  
Keyword(s):  
Microbial Interactions ◽  
Host Cells ◽  
Metabolic Phenotype ◽  
Community Members ◽  
Metabolic Phenotypes ◽  
Culture Independent ◽  
Microbe Interactions ◽  
Host Microbe Interactions ◽  
Atmospheric Pressure Mass Spectrometry

Spatial metabolomics describes the location and chemistry of small molecules involved in metabolic phenotypes, defense molecules and chemical interactions in natural communities. Most current techniques are unable to spatially link the genotype and metabolic phenotype of microorganisms in situ at a scale relevant to microbial interactions. Here, we present a spatial metabolomics pipeline (metaFISH) that combines fluorescence in situ hybridization (FISH) microscopy and high-resolution atmospheric pressure mass spectrometry imaging (AP-MALDI-MSI) to image host-microbe symbioses and their metabolic interactions. metaFISH aligns and integrates metabolite and fluorescent images at the micrometer-scale for a spatial assignment of host and symbiont metabolites on the same tissue section. To illustrate the advantages of metaFISH, we mapped the spatial metabolome of a deep-sea mussel and its intracellular symbiotic bacteria at the scale of individual epithelial host cells. Our analytical pipeline revealed metabolic adaptations of the epithelial cells to the intracellular symbionts, a variation in metabolic phenotypes in one symbiont type, and novel symbiosis metabolites. metaFISH provides a culture-independent approach to link metabolic phenotypes to community members in situ - a powerful tool for microbiologists across fields.

Harris, Chomsky and the origins of transformational grammar

2016 ◽  
Vol 39 (1) ◽  
pp. 48-87
Author(s):  
Giorgio Graffi
Keyword(s):  
Present Article ◽  
The Other ◽  
Auxiliary System ◽  
Transformational Grammar ◽  
Content Type ◽  
The One ◽  
Working Out ◽  
Shed Light

According to Chomsky’s report of the mid 1970s, he and Harris developed their theories in an essentially independent way; whereas according to some statements by Harris, some contact actually took place between them. To shed light on this issue, it may be useful to systematically compare their respective views of the notion ‘transformation’ as well as their analyses of certain syntactic phenomena. Among the topics dealt with in the present article are: the system of syntactic categories and their symbols; the notion of ‘zero elements’; the phenomenon of discontinuous constituents; the English auxiliary system; wh-constructions; the typology of transformations; the notions of ‘kernel’ and ‘kernel sentence’. Several of these analyses show many points of contact between the two scholars (e.g., the analysis of wh-constructions or that of English auxiliaries), which allow us to maintain that they surely influenced each other. The overall differences between the two models are also clear: the transformational relation holds between sentences in Harris’s framework, while it holds between underlying strings on the one hand and actual sentences on the other in Chomsky’s. As a consequence of this different view of the notion of transformation, two problems which were fundamental for Chomsky had no importance for Harris, namely the order of transformations and the distinction between optional and obligatory transformations. It can therefore be concluded that, if the two scholars certainly influenced each other when they were working out their respective transformational theories, their theoretical views were acutely different almost from the beginning.

scholarly journals Unexpected Specificity of Interspecies Cobamide Transfer from Geobacter spp. to Organohalide-Respiring Dehalococcoides mccartyi Strains

2012 ◽  
Vol 78 (18) ◽  
pp. 6630-6636 ◽  
Author(s):  
Jun Yan ◽  
Kirsti M. Ritalahti ◽  
Darlene D. Wagner ◽  
Frank E. Löffler
Keyword(s):  
Reductive Dechlorination ◽  
De Novo ◽  
Synthetic Medium ◽  
Geobacter Sulfurreducens ◽  
Rrna Gene ◽  
Content Type ◽  
Reductive Dehalogenase ◽  
Dehalococcoides Mccartyi ◽  
Gene Copies ◽  
Pure Cultures

ABSTRACTDehalococcoides mccartyistrains conserve energy from reductive dechlorination reactions catalyzed by corrinoid-dependent reductive dehalogenase enzyme systems.Dehalococcoideslacks the ability forde novocorrinoid synthesis, and pure cultures require the addition of cyanocobalamin (vitamin B12) for growth. In contrast,Geobacter lovleyi, which dechlorinates tetrachloroethene tocis-1,2-dichloroethene (cis-DCE), and the nondechlorinating speciesGeobacter sulfurreducenshave complete sets of cobamide biosynthesis genes and produced 12.9 ± 2.4 and 24.2 ± 5.8 ng of extracellular cobamide per liter of culture suspension, respectively, during growth with acetate and fumarate in a completely synthetic medium.G. lovleyi-D. mccartyistrain BAV1 or strain FL2 cocultures provided evidence for interspecies corrinoid transfer, andcis-DCE was dechlorinated to vinyl chloride and ethene concomitant withDehalococcoidesgrowth. In contrast, negligible increase inDehalococcoides16S rRNA gene copies and insignificant dechlorination occurred inG. sulfurreducens-D. mccartyistrain BAV1 or strain FL2 cocultures. Apparently,G. lovleyiproduces a cobamide that complementsDehalococcoides' nutritional requirements, whereasG. sulfurreducensdoes not. Interestingly,Dehalococcoidesdechlorination activity and growth could be restored inG. sulfurreducens-Dehalococcoidescocultures by adding 10 μM 5′,6′-dimethylbenzimidazole. Observations made with theG. sulfurreducens-Dehalococcoidescocultures suggest that the exchange of the lower ligand generated a cobalamin, which supportedDehalococcoidesactivity. These findings have implications forin situbioremediation and suggest that the corrinoid metabolism ofDehalococcoidesmust be understood to faithfully predict, and possibly enhance, reductive dechlorination activities.

scholarly journals Versatility in Corrinoid Salvaging and Remodeling Pathways Supports Corrinoid-Dependent Metabolism in Dehalococcoides mccartyi

2012 ◽  
Vol 78 (21) ◽  
pp. 7745-7752 ◽  
Author(s):  
Shan Yi ◽  
Erica C. Seth ◽  
Yu-Jie Men ◽  
Sally P. Stabler ◽  
Robert H. Allen ◽  
...  
Keyword(s):  
De Novo ◽  
Chlorinated Solvents ◽  
Axial Ligand ◽  
Content Type ◽  
Dehalococcoides Mccartyi ◽  
Axial Ligands ◽  
The Common ◽  
Enzyme Cofactors ◽  
Lower Ligand ◽  
Insight Into

ABSTRACTCorrinoids are cobalt-containing molecules that function as enzyme cofactors in a wide variety of organisms but are produced solely by a subset of prokaryotes. Specific corrinoids are identified by the structure of their axial ligands. The lower axial ligand of a corrinoid can be a benzimidazole, purine, or phenolic compound. Though it is known that many organisms obtain corrinoids from the environment, the variety of corrinoids that can serve as cofactors for any one organism is largely unstudied. Here, we examine the range of corrinoids that function as cofactors for corrinoid-dependent metabolism inDehalococcoides mccartyistrain 195.Dehalococcoidesbacteria play an important role in the bioremediation of chlorinated solvents in the environment because of their unique ability to convert the common groundwater contaminants perchloroethene and trichloroethene to the innocuous end product ethene. All isolatedD. mccartyistrains require exogenous corrinoids such as vitamin B12for growth. However, like many other corrinoid-dependent bacteria, none of the well-characterizedD. mccartyistrains has been shown to be capable of synthesizing corrinoidsde novo. In this study, we investigate the ability ofD. mccartyistrain 195 to use specific corrinoids, as well as its ability to modify imported corrinoids to a functional form. We show that strain 195 can use only specific corrinoids containing benzimidazole lower ligands but is capable of remodeling other corrinoids by lower ligand replacement when provided a functional benzimidazole base. This study of corrinoid utilization and modification byD. mccartyiprovides insight into the array of strategies that microorganisms employ in acquiring essential nutrients from the environment.

Exploring the dynamic influences and interaction effects of signals on backers’ investment in the crowdfunding market

2019 ◽  
Vol 33 (2) ◽  
pp. 792-812 ◽  
Author(s):  
Yang Song ◽  
Hong Wu ◽  
Jingdong Ma ◽  
Naiji Lu
Keyword(s):  
Panel Data ◽  
Negative Binomial ◽  
Early Stage ◽  
Substitution Effect ◽  
Interaction Effects ◽  
Data Set ◽  
Content Type ◽  
Funding Cycle ◽  
Practical Implications ◽  
Shed Light

Purpose As a standard source of capital for entrepreneurs, crowdfunding has recently gained wide attention in business and academia. With scientific endorsement, some research is conducted to explore the antecedents of online crowdfunding success. The factors that can influence the backers’ investment which is the key to success are information from prior backers’ and creators’ behaviors. Based on the signaling theory, the purpose of this paper is to systematically investigate the dynamic influences and interaction effects of signals with different forms (action-based or opinion-based signals) and sources (creator-sourced or backer-sourced signals) on backers’ investment behaviors over a project-funding cycle. Design/methodology/approach A panel data set of 3,010 projects with 640,625 transaction records from April 28, 2013 to September 31, 2017 is collected from a famous online crowdfunding platform – Zhongchou.cn in China and the negative binomial panel data model with fixed effect is used to obtain our empirical results. Findings The findings demonstrate that the work of different signals is significantly effective at the early stage of a project and decreases with time. Furthermore, our results show that there are both synergistic effect and substitution effect among different signals. Specifically, the direction of interaction effect depends on the forms of signals and the backers’ sensitivity toward that signal, and the interaction effects are also dynamic. Originality/value This paper has shed light on the roles of different signal types and their interactions in influencing funding behavior over a project-funding cycle, enriched the literature on crowdfunding and provided both theoretical and practical implications.

Professionalism and professionalization of early stage teachers in higher education

2020 ◽  
Vol 12 (5) ◽  
pp. 1175-1187
Author(s):  
Cipto Wardoyo ◽  
Aulia Herdiani ◽  
Nurdian Susilowati ◽  
Muhammad Syahril Harahap
Keyword(s):  
Higher Education ◽  
Design Methodology ◽  
Early Stage ◽  
Initial Period ◽  
Reciprocal Relationship ◽  
Government Policies ◽  
Content Type ◽  
Individual Needs ◽  
The One

PurposeThe aim of the study is to test whether an increase in professionalism has a reciprocal relationship with the professionalization of early-stage lecturers.Design/methodology/approachResearch with the topic of professionalism and professionalization of educators does not consider the reciprocal relationship. Most research only test the one-way relationship between professionalism and professionalization as the consequence of the application of government policies on colleges. Analysis in this research was carried out on the perspectives of early-stage lecturers on professionalism and professionalization, each conducted reciprocally for period tn from tn−1.FindingsIn the initial period of the profession, lecturers will tend to work hard to increase the competence and income they possess. The achieved increase in competence is based on the demand to develop professionalism, while the increase in income is based more on the demands of individual needs. In general, an increase in the professionalism of lecturers will be followed by an increase in income (professionalization). However, at some point, this increase in professionalism will experience stagnation, although the professionalization they possess continues to increase.Research limitations/implicationsThe data of material used in this research only consist of estimated figures from each respondent, while the components of appreciation for lecturers may vary depending on their respective institutions.Originality/valuePrevious studies have extensively observed the determinants of teachers’ professionalism and professionalization; however, how professionalism and professionalization reciprocally influence each other in terms of career periods has not been taken into account.

Entrepreneurial public leadership: 5As framework for wellness promotion

2019 ◽  
Vol 57 (7) ◽  
pp. 1443-1456
Author(s):  
Grant Beebe ◽  
Milorad Novicevic ◽  
Ifeoluwa Tobi Popoola ◽  
Joseph (Jody) Holland
Keyword(s):  
Public Health ◽  
Early Stage ◽  
Community Members ◽  
Content Type ◽  
Wellness Promotion ◽  
Public Leadership ◽  
Study Results ◽  
Community Wellness ◽  
Public Leaders

Purpose The purpose of this paper is to develop a 5As framework for entrepreneurial nudge public leadership for health and wellness promotion based on two exemplary cases in Mississippi. Design/methodology/approach The authors use a “case within a case” study design to develop the 5As public influence framework for entrepreneurial public leadership. Findings Based on the investigated cases of healthcare and wellness promotion in Hernando and Charleston, Mississippi, the authors developed the 5As framework for wellness promotion dimensions of awareness, assistance, alignment, association, and assessment. This framework is applicable to the lived experiences of community members, leaders, healthcare providers, and government. Research limitations/implications The study results provide a compelling insight into early-stage formation of entrepreneurial public leadership. However, the study results lack generalizability due to the case study approach used. Practical implications This study can assist entrepreneurial public leaders and policy-makers align their strategic wellness goals, initiatives, and policies that motivate community members to seek and receive supporting services. Originality/value Developing an original framework for wellness promotion useful to both healthcare practitioners and public leaders, this study contributes to the extant literature on public health leadership and proposes mechanisms for addressing community wellness needs. The framework is designed to address public health concerns by integrating public leadership strategies aimed at linking with existing community wellness and healthcare services.

Association of the Non-Motor Burden with Patterns of Striatal Dopamine Loss in de novo Parkinson’s Disease

2020 ◽  
Vol 10 (4) ◽  
pp. 1541-1549
Author(s):  
Seok Jong Chung ◽  
Sangwon Lee ◽  
Han Soo Yoo ◽  
Yang Hyun Lee ◽  
Hye Sun Lee ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
De Novo ◽  
Early Stage ◽  
Striatal Dopamine ◽  
Motor Deficits ◽  
Dopamine Depletion ◽  
Severe Motor ◽  
Severe Group ◽  
Striatal Dopamine Depletion

Background: Striatal dopamine deficits play a key role in the pathogenesis of Parkinson’s disease (PD), and several non-motor symptoms (NMSs) have a dopaminergic component. Objective: To investigate the association between early NMS burden and the patterns of striatal dopamine depletion in patients with de novo PD. Methods: We consecutively recruited 255 patients with drug-naïve early-stage PD who underwent 18F-FP-CIT PET scans. The NMS burden of each patient was assessed using the NMS Questionnaire (NMSQuest), and patients were divided into the mild NMS burden (PDNMS-mild) (NMSQuest score <6; n = 91) and severe NMS burden groups (PDNMS-severe) (NMSQuest score >9; n = 90). We compared the striatal dopamine transporter (DAT) activity between the groups. Results: Patients in the PDNMS-severe group had more severe parkinsonian motor signs than those in the PDNMS-mild group, despite comparable DAT activity in the posterior putamen. DAT activity was more severely depleted in the PDNMS-severe group in the caudate and anterior putamen compared to that in the PDMNS-mild group. The inter-sub-regional ratio of the associative/limbic striatum to the sensorimotor striatum was lower in the PDNMS-severe group, although this value itself lacked fair accuracy for distinguishing between the patients with different NMS burdens. Conclusion: This study demonstrated that PD patients with severe NMS burden exhibited severe motor deficits and relatively diffuse dopamine depletion throughout the striatum. These findings suggest that the level of NMS burden could be associated with distinct patterns of striatal dopamine depletion, which could possibly indicate the overall pathological burden in PD.

The Application of UX Research in New Energy Vehicle Innovation

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Menghan TAO ◽  
Ning XIAO ◽  
Xingfu ZHAO ◽  
Wenbin LIU
Keyword(s):  
Early Stage ◽  
Rapid Expansion ◽  
The Other ◽  
Innovative Product ◽  
Stage Of Development ◽  
New Energy ◽  
New Energy Vehicle ◽  
The One ◽  
New Energy Vehicles ◽  
Degree Of Innovation

New energy vehicles(NEV) as a new thing for sustainable development, in China, on the one hand has faced the rapid expansion of the market; the other hand, for the new NEV users, the current NEVs cannot keep up with the degree of innovation. This paper demonstrates the reasons for the existence of this systematic challenge, and puts forward the method of UX research which is different from the traditional petrol vehicles research in the early stage of development, which studies from the user's essence level, to form the innovative product programs which meet the needs of users and being real attractive.

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