scholarly journals Culture and genome-based analysis of four soil Clostridium isolates reveal their potential for antimicrobial production

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Amila S. N. W. Pahalagedara ◽  
Ruy Jauregui ◽  
Paul Maclean ◽  
Eric Altermann ◽  
Steve Flint ◽  
...  
Keyword(s):  
Current Knowledge ◽  
Biological Activities ◽  
Extreme Environments ◽  
Bioactive Compound ◽  
Gene Clusters ◽  
Future Research ◽  
Antimicrobial Compounds ◽  
A Genome ◽  
Modified Peptides ◽  
Current Knowledge Base

Abstract Background Soil bacteria are a major source of specialized metabolites including antimicrobial compounds. Yet, one of the most diverse genera of bacteria ubiquitously present in soil, Clostridium, has been largely overlooked in bioactive compound discovery. As Clostridium spp. thrive in extreme environments with their metabolic mechanisms adapted to the harsh conditions, they are likely to synthesize molecules with unknown structures, properties, and functions. Therefore, their potential to synthesize small molecules with biological activities should be of great interest in the search for novel antimicrobial compounds. The current study focused on investigating the antimicrobial potential of four soil Clostridium isolates, FS01, FS2.2 FS03, and FS04, using a genome-led approach, validated by culture-based methods. Results Conditioned/spent media from all four Clostridium isolates showed varying levels of antimicrobial activity against indicator microorganism; all four isolates significantly inhibited the growth of Pseudomonas aeruginosa. FS01, FS2.2, and FS04 were active against Bacillus mycoides and FS03 reduced the growth of Bacillus cereus. Phylogenetic analysis together with DNA-DNA hybridization (dDDH), average nucleotide identity (ANI), and functional genome distribution (FGD) analyses confirmed that FS01, FS2.2, and FS04 belong to the species Paraclostridium bifermentans, Clostridium cadaveris, and Clostridium senegalense respectively, while FS03 may represent a novel species of the genus Clostridium. Bioinformatics analysis using antiSMASH 5.0 predicted the presence of eight biosynthetic gene clusters (BGCs) encoding for the synthesis of ribosomally synthesized post-translationally modified peptides (RiPPs) and non-ribosomal peptides (NRPs) in four genomes. All predicted BGCs showed no similarity with any known BGCs suggesting novelty of the molecules from those predicted gene clusters. In addition, the analysis of genomes for putative virulence factors revealed the presence of four putative Clostridium toxin related genes in FS01 and FS2.2 genomes. No genes associated with the main Clostridium toxins were identified in the FS03 and FS04 genomes. Conclusions The presence of BGCs encoding for uncharacterized RiPPs and NRPSs in the genomes of antagonistic Clostridium spp. isolated from farm soil indicated their potential to produce novel secondary metabolites. This study serves as a basis for the identification and characterization of potent antimicrobials from these soil Clostridium spp. and expands the current knowledge base, encouraging future research into bioactive compound production in members of the genus Clostridium.

Clinical Management of Obsessive-Compulsive and Related Disorders

2017 ◽  
Author(s):  
Samuel R Chamberlain
Keyword(s):  
Body Dysmorphic Disorder ◽  
Current Knowledge ◽  
Assessment Tools ◽  
Future Research ◽  
Obsessive Compulsive ◽  
Compulsive Disorder ◽  
Medical Issues ◽  
Evidence Based Treatments ◽  
Current Knowledge Base ◽  
Hair Pulling Disorder

Obsessive-compulsive and related disorders (OCRDs) now have their own category in the Diagnostic and Statistical Manual of Mental Disorders, fifth edition. Disorders currently classified as OCRDs are obsessive-compulsive disorder, trichotillomania (hair pulling disorder), excoriation (skin picking) disorder, hoarding disorder, and body dysmorphic disorder. Collectively, the OCRDs are prevalent, cause considerable functional impairment, and are often overlooked by clinicians. This review surveys current definitions and diagnosis of OCRDs, highlighting recommended assessment tools, differential diagnoses, and medical issues. The heritability of OCRDs is examined, based on available twin data, along with implicated genetic factors. Neurobiological understanding of OCRDs is outlined, focusing on dysregulation of habit generation and top-down response control corticostriatal pathways. The review then highlights evidence-based treatments for OCRDs, which differ considerably between individual disorders. Treatment guidance includes descriptions of target medication doses and therapy content. Lastly, limitations in the current knowledge base for OCRDs are reviewed, with implications for future research directions. This review contains 1 figure, 7 tables, and 40 references. Key words: compulsivity, dopamine, glutamate, impulsivity, screening for OCD, serotonin 

scholarly journals Dual Role of the PTPN13 Tyrosine Phosphatase in Cancer

Biomolecules ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1659
Author(s):  
Soha Mcheik ◽  
Leticia Aptecar ◽  
Peter Coopman ◽  
Véronique D’Hondt ◽  
Gilles Freiss
Keyword(s):  
Current Knowledge ◽  
Biological Activities ◽  
Tyrosine Phosphatase ◽  
Tumor Formation ◽  
Receptor Protein ◽  
Cell Junction ◽  
Future Research ◽  
Tyrosine Kinase Signaling ◽  
Cancer Types ◽  
Oncogenic Protein

In this review article, we present the current knowledge on PTPN13, a class I non-receptor protein tyrosine phosphatase identified in 1994. We focus particularly on its role in cancer, where PTPN13 acts as an oncogenic protein and also a tumor suppressor. To try to understand these apparent contradictory functions, we discuss PTPN13 implication in the FAS and oncogenic tyrosine kinase signaling pathways and in the associated biological activities, as well as its post-transcriptional and epigenetic regulation. Then, we describe PTPN13 clinical significance as a prognostic marker in different cancer types and its impact on anti-cancer treatment sensitivity. Finally, we present future research axes following recent findings on its role in cell junction regulation that implicate PTPN13 in cell death and cell migration, two major hallmarks of tumor formation and progression.

scholarly journals Service-Sales Ambidexterity: Evidence, Practice, and Opportunities for Future Research

2019 ◽  
Vol 23 (1) ◽  
pp. 13-21 ◽  
Author(s):  
Ko de Ruyter ◽  
Debbie Isobel Keeling ◽  
Ting Yu
Keyword(s):  
Service Delivery ◽  
Current Practice ◽  
Current Knowledge ◽  
Theoretical Development ◽  
Structural Knowledge ◽  
Future Research ◽  
Organizational Boundaries ◽  
Current Knowledge Base ◽  
Effective Service

Aligning the service-sales interface within and beyond organizational boundaries is worthwhile, yet many firms are not reaping the rewards of such practice. The managerial need for in-depth insights into the blending of selling and service delivery could be better informed through resolution of current open theoretical debates. This position article extends the current knowledge base on the service-sales interface in three ways. First, we offer a synopsis of current scholarly progress on blending service delivery with sales and identify contextual conditions that foster effective service-sales ambidexterity. Second, turning to current practice, we use an empirical case study to demonstrate how a multinational company strategically deploys online learning to bridge structural knowledge and skills gaps within its reseller network to build ambidextrous capacity in the channel and support solution selling. Complementing this human learning approach, we also explore recent advances in machine learning and their impact on the service-sales interface. Third, we blend these academic and practice perspectives to offer a service-sales interface agenda that identifies directions for future research in terms of both the theoretical development of ambidexterity and defining the effective blending of technologies at the service-sales interface that enables ambidexterity in practice.

Workplace Envy

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Michelle K. Duffy ◽  
KiYoung Lee ◽  
Elizabeth A. Adair
Keyword(s):  
Organizational Behavior ◽  
Online Publication ◽  
Current Knowledge ◽  
Cross Cultural ◽  
Future Research ◽  
Annual Review ◽  
Publication Date ◽  
The Past ◽  
Current Knowledge Base ◽  
Practical Implications

In the past 20 years, there has been a growing interest in the phenomenon of workplace envy. This article provides an overarching review and analysis of the workplace envy literature. We first consider conceptual and measurement challenges facing envy researchers. We then review the current knowledge base in the research with a focus on synthesizing what we have learned regarding workplace envy's transmutations, highlighting directions for future research. We explore two relatively understudied areas in the envy literature—antecedents of envy and the experience of being envied. We discuss methodologies used in the literature to study envy and outcomes and conclude with a focus on cross-cultural and practical implications. Expected final online publication date for the Annual Review of Organizational Psychology and Organizational Behavior, Volume 8 is January 21, 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Telework and Lifelong Learning

2021 ◽  
Vol 6 ◽  
Author(s):  
Cecilia Bjursell ◽  
Ingela Bergmo-Prvulovic ◽  
Joel Hedegaard
Keyword(s):  
Lifelong Learning ◽  
Social Inequalities ◽  
Current Knowledge ◽  
Age Groups ◽  
Working Life ◽  
Future Research ◽  
Literature Reviews ◽  
Research Questions ◽  
Current Knowledge Base ◽  
The Eu

The increase of telework during the pandemic is predicted to impact working life, not only in terms of a larger number of employees working from home, but more importantly, it may transform the way we conceptualise work. This will in turn impact systems for and participation in lifelong learning. There is a risk for increased social inequalities, as neither telework nor lifelong learning is evenly distributed among workers. Statistics on telework in the EU show that there are differences between age groups, nations, sectors, and professions. If these trends will steer forward, there is a risk of widening gaps between countries, companies, and workers. To establish the current knowledge base, we have gathered literature reviews from several disciplines. One finding is that the previous literature on telework has not included lifelong learning in any form (formal, non-formal and informal). Based on a review of previous studies, we suggest a number of research questions for future research. This is relevant as research about telework and lifelong learning has the potential to contribute to a sustainable working life in terms of providing more flexible arrangements for employees and to support the lifelong learning that takes place in contexts such as the office, home, online meetings, and virtual reality.

scholarly journals Expanded Natural Product Diversity Revealed by Analysis of Lanthipeptide-Like Gene Clusters in Actinobacteria

2015 ◽  
Vol 81 (13) ◽  
pp. 4339-4350 ◽  
Author(s):  
Qi Zhang ◽  
James R. Doroghazi ◽  
Xiling Zhao ◽  
Mark C. Walker ◽  
Wilfred A. van der Donk
Keyword(s):  
Natural Products ◽  
Natural Product ◽  
Gene Cluster ◽  
Posttranslational Modifications ◽  
Large Scale ◽  
Biological Activities ◽  
Gene Clusters ◽  
Chemical Diversity ◽  
Content Type ◽  
Modified Peptides

ABSTRACTLanthionine-containing peptides (lanthipeptides) are a rapidly growing family of polycyclic peptide natural products belonging to the large class of ribosomally synthesized and posttranslationally modified peptides (RiPPs). Lanthipeptides are widely distributed in taxonomically distant species, and their currently known biosynthetic systems and biological activities are diverse. Building on the recent natural product gene cluster family (GCF) project, we report here large-scale analysis of lanthipeptide-like biosynthetic gene clusters fromActinobacteria. Our analysis suggests that lanthipeptide biosynthetic pathways, and by extrapolation the natural products themselves, are much more diverse than currently appreciated and contain many different posttranslational modifications. Furthermore, lanthionine synthetases are much more diverse in sequence and domain topology than currently characterized systems, and they are used by the biosynthetic machineries for natural products other than lanthipeptides. The gene cluster families described here significantly expand the chemical diversity and biosynthetic repertoire of lanthionine-related natural products. Biosynthesis of these novel natural products likely involves unusual and unprecedented biochemistries, as illustrated by several examples discussed in this study. In addition, class IV lanthipeptide gene clusters are shown not to be silent, setting the stage to investigate their biological activities.

scholarly journals Genomic charting of ribosomally synthesized natural product chemical space facilitates targeted mining

2016 ◽  
Vol 113 (42) ◽  
pp. E6343-E6351 ◽  
Author(s):  
Michael A. Skinnider ◽  
Chad W. Johnston ◽  
Robyn E. Edgar ◽  
Chris A. Dejong ◽  
Nishanth J. Merwin ◽  
...  
Keyword(s):  
Natural Products ◽  
Genome Sequencing ◽  
Sequence Data ◽  
Chemical Space ◽  
Biological Activities ◽  
Global Analysis ◽  
Gene Clusters ◽  
Systematic Investigation ◽  
Chemical Structures ◽  
Modified Peptides

Microbial natural products are an evolved resource of bioactive small molecules, which form the foundation of many modern therapeutic regimes. Ribosomally synthesized and posttranslationally modified peptides (RiPPs) represent a class of natural products which have attracted extensive interest for their diverse chemical structures and potent biological activities. Genome sequencing has revealed that the vast majority of genetically encoded natural products remain unknown. Many bioinformatic resources have therefore been developed to predict the chemical structures of natural products, particularly nonribosomal peptides and polyketides, from sequence data. However, the diversity and complexity of RiPPs have challenged systematic investigation of RiPP diversity, and consequently the vast majority of genetically encoded RiPPs remain chemical “dark matter.” Here, we introduce an algorithm to catalog RiPP biosynthetic gene clusters and chart genetically encoded RiPP chemical space. A global analysis of 65,421 prokaryotic genomes revealed 30,261 RiPP clusters, encoding 2,231 unique products. We further leverage the structure predictions generated by our algorithm to facilitate the genome-guided discovery of a molecule from a rare family of RiPPs. Our results provide the systematic investigation of RiPP genetic and chemical space, revealing the widespread distribution of RiPP biosynthesis throughout the prokaryotic tree of life, and provide a platform for the targeted discovery of RiPPs based on genome sequencing.

Corporate Governance in the Hospitality and Tourism Industry: Theoretical Foundations and Future Research

2021 ◽  
pp. 109634802110117
Author(s):  
Yuan Li ◽  
Manisha Singal
Keyword(s):  
Corporate Governance ◽  
Current Knowledge ◽  
Theory Development ◽  
Tourism Industry ◽  
Future Research ◽  
General Management ◽  
Hospitality And Tourism ◽  
Hospitality And Tourism Industry ◽  
Current Knowledge Base ◽  
Theoretical Foundations

Although the importance of effective corporate governance for firm performance is recognized by scholars across hospitality and tourism (HT) as well as finance and general management fields, there seem to be several gaps, mixed findings, and conflicting results. To facilitate scholarly advancement, identify gaps in the current knowledge base, make suggestions for theory development, and provide direction for future research, we undertake a systematic review of research on corporate governance in the HT literature. Based on 120 peer-reviewed articles published since 1961, we identify 21 themes explored by scholars, and find that topics related to institutional ownership, determinants of executive compensation, board size, and merger and acquisition outcomes are commonly examined, whereas topics related to family ownership, debt, and regulation/law are seldom explored. Our comprehensive review contributes to the literature by synthesizing current knowledge and offering suggestions to scholars to extend corporate governance literature published in the HT field.

scholarly journals Genome Mining for Antimicrobial Compounds in Wild Marine Animals-associated Enterococci

2021 ◽  
Author(s):  
Janira Prichula ◽  
Muriel Primon-Barros ◽  
Romeu Luz ◽  
Ícaro Castro ◽  
Thiago Paim ◽  
...  
Keyword(s):  
Genome Mining ◽  
Bioactive Compound ◽  
Gene Clusters ◽  
Marine Animal ◽  
Antimicrobial Compounds ◽  
Biosynthetic Gene ◽  
Biosynthetic Gene Clusters ◽  
Marine Animals ◽  
Host Health ◽  
Low Toxicity

Abstract New ecosystems are being actively mined for new bioactive compounds. Because of the large amount of unexplored biodiversity, bacteria from marine environments are especially promising. Further, host-associated microbes are of special interest because of their low toxicity and compatibility with host health. Here we identified and characterized biosynthetic gene clusters encoding antimicrobial compounds in host-associated enterococcal recovered from fecal samples of wild marine animals remote from human-affected ecosystems. Putative biosynthetic gene clusters in the genomes of 22 Enterococcus strains of marine origin were predicted using antiSMASH5 and Bagel4 bioinformatic software. At least one gene cluster encoding a putative bioactive compound precursor was identified in each genome. Collectively, 73 putative antimicrobial compounds were identified, including 61 bacteriocins (83.56 %), 10 terpenes (13.70 %), and two (2.74 %) related to putative nonribosomal peptides (NRPs). Two of the species studied, Enterococcus avium and Enterococcus mundtti, are rare causes of human disease and were found to lack any known pathogenic determinants but yet possessed bacteriocin biosynthetic genes, suggesting possible additional utility as probiotics. Wild marine animal-associated enterococci from human-remote ecosystems provide a potentially rich source for new antimicrobial compounds of therapeutic and industrial value, and potential probiotic application.

The knowledge base of Chinese as a second language teaching in K-12 settings

2018 ◽  
Vol 53 (3) ◽  
pp. 295-307
Author(s):  
Ziyi Geng ◽  
John Murphy
Keyword(s):  
Second Language ◽  
Knowledge Base ◽  
Current Knowledge ◽  
Teacher Cognition ◽  
Future Research ◽  
Language Teacher ◽  
Content Type ◽  
Language Pedagogy ◽  
Current Knowledge Base ◽  
K 12

Abstract The field of teaching Chinese as a second language (CSL) is expanding and growing in importance worldwide. Related fields, such as Chinese language pedagogy, language policy, and the acquisition of Chinese as a second language, are attracting increased attention in research. However, research into K-12 CSL teacher cognition (what teachers know, think, and believe) has been very limited. It has been reported that more understanding of language teacher cognition has significant impacts on the development of teacher training and professional development programs (Borg, 2015; Kubanyiova & Feryok, 2015). Many aspects of CSL teacher cognition are underexplored when compared with language teacher cognition research in general and K-12 language teacher cognition research specifically. This article reviews current theoretical and empirical research into language teacher cognition with a particular focus on existing studies in the field of CSL teaching in the context of K-12 education. The purposes of the review article are (1) to document the current knowledge base of CSL teaching, and (2) to discuss current gaps in and future directions of teacher cognition research in this area. It first discusses general theories and research concerning second language teacher cognition within current research paradigms, and then provides a review of CSL teacher cognition research. Finally, it reviews pressing issues and suggests directions for future research in K-12 Chinese teacher cognition.

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