scholarly journals Dynamic role of single‐celled fungi in ruminal microbial ecology and activities

2019 ◽  
Vol 128 (4) ◽  
pp. 950-965 ◽  
Author(s):  
M.M.Y. Elghandour ◽  
A. Khusro ◽  
M.J. Adegbeye ◽  
Z. Tan ◽  
S.H. Abu Hafsa ◽  
...  
Keyword(s):  
Microbial Ecology

scholarly journals Bacteriocin-like activity of oral Fusobacterium nucleatum isolated from human and non-human primates

1999 ◽  
Vol 30 (4) ◽  
pp. 324-346 ◽  
Author(s):  
Elerson Gaetti-Jardim Júnior ◽  
Mario Julio Avila-Campos
Keyword(s):  
Oral Cavity ◽  
Microbial Ecology ◽  
Dental Plaque ◽  
Fusobacterium Nucleatum ◽  
Antagonistic Activity ◽  
Healthy Individuals ◽  
Bacterial Microbiota ◽  
Reference Strains

Fusobacterium nucleatum is indigenous of the human oral cavity and has been involved in different infectious processes. The production of bacteriocin-like substances may be important in regulation of bacterial microbiota in oral cavity. The ability to produce bacteriocin-like substances by 80 oral F. nucleatum isolates obtained from periodontal patients, healthy individuals and Cebus apella monkeys, was examinated. 17.5% of all tested isolates showed auto-antagonism and 78.8% iso- or hetero-antagonism. No isolate from monkey was capable to produce auto-inhibition. In this study, the antagonistic substances production was variable in all tested isolates. Most of the F. nucleatum showed antagonistic activity against tested reference strains. These data suggest a possible participation of these substances on the oral microbial ecology in humans and animals. However, the role of bacteriocins in regulating dental plaque microbiota in vivo is discussed.

scholarly journals Effects of atrazine on the black community land function and role of microbial ecology

2020 ◽  
Vol 446 ◽  
pp. 032093
Author(s):  
Yaosheng Zhang ◽  
Long Tian ◽  
Ruixi Ma ◽  
Yanxiang Wei ◽  
Jiali Yang ◽  
...  
Keyword(s):  
Microbial Ecology ◽  
Black Community

scholarly journals Oral Microbial Ecology and the Role of Salivary Immunoglobulin A

1998 ◽  
Vol 62 (1) ◽  
pp. 71-109 ◽  
Author(s):  
Harold Marcotte ◽  
Marc C. Lavoie
Keyword(s):  
Immune System ◽  
Oral Cavity ◽  
Microbial Ecology ◽  
Periodontal Diseases ◽  
Immunoglobulin A ◽  
Basic Knowledge ◽  
Oral Microbiota ◽  
Indigenous Bacteria ◽  
Indigenous Microbiota

SUMMARY In the oral cavity, indigenous bacteria are often associated with two major oral diseases, caries and periodontal diseases. These diseases seem to appear following an inbalance in the oral resident microbiota, leading to the emergence of potentially pathogenic bacteria. To define the process involved in caries and periodontal diseases, it is necessary to understand the ecology of the oral cavity and to identify the factors responsible for the transition of the oral microbiota from a commensal to a pathogenic relationship with the host. The regulatory forces influencing the oral ecosystem can be divided into three major categories: host related, microbe related, and external factors. Among host factors, secretory immunoglobulin A (SIgA) constitutes the main specific immune defense mechanism in saliva and may play an important role in the homeostasis of the oral microbiota. Naturally occurring SIgA antibodies that are reactive against a variety of indigenous bacteria are detectable in saliva. These antibodies may control the oral microbiota by reducing the adherence of bacteria to the oral mucosa and teeth. It is thought that protection against bacterial etiologic agents of caries and periodontal diseases could be conferred by the induction of SIgA antibodies via the stimulation of the mucosal immune system. However, elucidation of the role of the SIgA immune system in controlling the oral indigenous microbiota is a prerequisite for the development of effective vaccines against these diseases. The role of SIgA antibodies in the acquisition and the regulation of the indigenous microbiota is still controversial. Our review discusses the importance of SIgA among the multiple factors that control the oral microbiota. It describes the oral ecosystems, the principal factors that may control the oral microbiota, a basic knowledge of the secretory immune system, the biological functions of SIgA, and, finally, experiments related to the role of SIgA in oral microbial ecology.

scholarly journals Impact of cleaning and disinfection procedures on microbial ecology and Salmonella antimicrobial resistance in a pig slaughterhouse

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Arnaud Bridier ◽  
Patricia Le Grandois ◽  
Marie-Hélène Moreau ◽  
Charleyne Prénom ◽  
Alain Le Roux ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Microbial Ecology ◽  
Bacterial Diversity ◽  
Food Environments ◽  
Short Term ◽  
Short Term Study ◽  
Before And After ◽  
Associated Surfaces ◽  
Cleaning And Disinfection

Abstract To guarantee food safety, a better deciphering of ecology and adaptation strategies of bacterial pathogens such as Salmonella in food environments is crucial. The role of food processing conditions such as cleaning and disinfection procedures on antimicrobial resistance emergence should especially be investigated. In this work, the prevalence and antimicrobial resistance of Salmonella and the microbial ecology of associated surfaces communities were investigated in a pig slaughterhouse before and after cleaning and disinfection procedures. Salmonella were detected in 67% of samples and isolates characterization revealed the presence of 15 PFGE-patterns belonging to five serotypes: S.4,5,12:i:-, Rissen, Typhimurium, Infantis and Derby. Resistance to ampicillin, sulfamethoxazole, tetracycline and/or chloramphenicol was detected depending on serotypes. 16S rRNA-based bacterial diversity analyses showed that Salmonella surface associated communities were highly dominated by the Moraxellaceae family with a clear site-specific composition suggesting a persistent colonization of the pig slaughterhouse. Cleaning and disinfection procedures did not lead to a modification of Salmonella susceptibility to antimicrobials in this short-term study but they tended to significantly reduce bacterial diversity and favored some genera such as Rothia and Psychrobacter. Such data participate to the construction of a comprehensive view of Salmonella ecology and antimicrobial resistance emergence in food environments in relation with cleaning and disinfection procedures.

scholarly journals Central Role of the Cell in Microbial Ecology

2009 ◽  
Vol 73 (4) ◽  
pp. 712-729 ◽  
Author(s):  
Karsten Zengler
Keyword(s):  
Microbial Diversity ◽  
Microbial Ecology ◽  
Single Cell ◽  
Community Composition ◽  
Pure Culture ◽  
Current Knowledge ◽  
Community Level ◽  
Central Unit ◽  
Genome Heterogeneity

SUMMARY Over the last few decades, advances in cultivation-independent methods have significantly contributed to our understanding of microbial diversity and community composition in the environment. At the same time, cultivation-dependent methods have thrived, and the growing number of organisms obtained thereby have allowed for detailed studies of their physiology and genetics. Still, most microorganisms are recalcitrant to cultivation. This review not only conveys current knowledge about different isolation and cultivation strategies but also discusses what implications can be drawn from pure culture work for studies in microbial ecology. Specifically, in the light of single-cell individuality and genome heterogeneity, it becomes important to evaluate population-wide measurements carefully. An overview of various approaches in microbial ecology is given, and the cell as a central unit for understanding processes on a community level is discussed.

scholarly journals Optogenetic Tools for Control of Public Goods in Saccharomyces cerevisiae

mSphere ◽  
2021 ◽  
Vol 6 (4) ◽  
Author(s):  
Neydis Moreno Morales ◽  
Michael T. Patel ◽  
Cameron J. Stewart ◽  
Kieran Sweeney ◽  
Megan N. McClean
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Community Development ◽  
Public Goods ◽  
Microbial Communities ◽  
Microbial Ecology ◽  
Intercellular Interactions ◽  
Recent Advances

Recent advances in microbial ecology have highlighted the importance of intercellular interactions in controlling the development, composition, and resilience of microbial communities. In order to better understand the role of these interactions in governing community development, it is critical to be able to alter them in a controlled manner.

scholarly journals The Landscape of Recombination Events That Create Nonribosomal Peptide Diversity

2021 ◽  
Author(s):  
Martin Baunach ◽  
Somak Chowdhury ◽  
Pierre Stallforth ◽  
Elke Dittmann
Keyword(s):  
Microbial Ecology ◽  
Structural Diversity ◽  
Selectivity Filter ◽  
Nonribosomal Peptides ◽  
Nonribosomal Peptide ◽  
Bacterial Phyla ◽  
Multienzyme Complexes ◽  
Key Driver ◽  
Structural Diversification

Abstract Nonribosomal peptides (NRP) are crucial molecular mediators in microbial ecology and provide indispensable drugs. Nevertheless, the evolution of the flexible biosynthetic machineries that correlates with the stunning structural diversity of NRPs is poorly understood. Here, we show that recombination is a key driver in the evolution of bacterial NRP synthetase (NRPS) genes across distant bacterial phyla, which has guided structural diversification in a plethora of NRP families by extensive mixing and matching of biosynthesis genes. The systematic dissection of a large number of individual recombination events did not only unveil a striking plurality in the nature and origin of the exchange units but allowed the deduction of overarching principles that enable the efficient exchange of adenylation (A) domain substrates while keeping the functionality of the dynamic multienzyme complexes. In the majority of cases, recombination events have targeted variable portions of the Acore domains, yet domain interfaces and the flexible Asub domain remained untapped. Our results strongly contradict the widespread assumption that adenylation and condensation (C) domains coevolve and significantly challenge the attributed role of C domains as stringent selectivity filter during NRP synthesis. Moreover, they teach valuable lessons on the choice of natural exchange units in the evolution of NRPS diversity, which may guide future engineering approaches.

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