scholarly journals Recent Advances in the Mechanisms and Regulation of QS in Dairy Spoilage by Pseudomonas spp.

Foods ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3088
Author(s):  
Laura Quintieri ◽  
Leonardo Caputo ◽  
Milena Brasca ◽  
Francesca Fanelli
Keyword(s):  
Quorum Sensing ◽  
Low Temperatures ◽  
Metabolic Pathways ◽  
Dairy Products ◽  
Molecular Mechanisms ◽  
Multidrug Resistant ◽  
Food Spoilage ◽  
Homoserine Lactones ◽  
Quality And Shelf Life

Food spoilage is a serious issue dramatically impacting the worldwide need to counteract food insecurity. Despite the very expensive application of low temperatures, the proper conservation of fresh dairy products is continuously threatened at different stages of production and commercialization by psychrotrophic populations mainly belonging to the Pseudomonas genus. These bacteria cause discolouration, loss of structure, and off-flavours, with fatal implications on the quality and shelf-life of products. While the effects of pseudomonad decay have been widely reported, the mechanisms responsible for the activation and regulation of spoilage pathways are still poorly explored. Recently, molecule signals and regulators involved in quorum sensing (QS), such as homoserine lactones, the luxR/luxI system, hdtS, and psoR, have been detected in spoiled products and bacterial spoiler species; this evidence suggests the role of bacterial cross talk in dairy spoilage and paves the way towards the search for novel preservation strategies based on QS inhibition. The aim of this review was to investigate the advancements achieved by the application of omic approaches in deciphering the molecular mechanisms controlled by QS systems in pseudomonads, by focusing on the regulators and metabolic pathways responsible for spoilage of fresh dairy products. In addition, due the ability of pseudomonads to quickly spread in the environment as biofilm communities, which may also include pathogenic and multidrug-resistant (MDR) species, the risk derived from the gaps in clearly defined and regulated sanitization actions is underlined.

Growth of Salmonella Enteritidis in the presence of quorum sensing signaling compounds produced by Pseudomonas aeruginosa

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Weijia He ◽  
Huamei Yang ◽  
Xiang Wang ◽  
Hongmei Li ◽  
Qingli Dong
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Salmonella Enteritidis ◽  
Culture Supernatant ◽  
Lag Time ◽  
Bacterial Communication ◽  
Homoserine Lactones ◽  
Positive Effects ◽  
Kinetics Of

Abstract Quorum sensing (QS) can exist in food-related bacteria and potentially affect bacterial growth through acyl-homoserine lactones (AHLs). To verify the role of QS compounds in the cell-free supernatant, this study examined the effect of supernatant extracted from Pseudomonas aeruginosa culture on the growth kinetics of Salmonella Enteritidis. The results showed that the lag time (λ) of S. Enteritidis was apparently reduced (p < 0.05) under the influence of P. aeruginosa culture supernatant compared with the S. Enteritidis culture supernatant. HPLC-MS/MS test demonstrated that AHLs secreted by P. aeruginosa were mainly C14-HSL with a content of 85.71 μg/mL and a small amount of 3-oxo-C12-HSL. In addition, the commercially synthetic C14-HSL had positive effects on the growth of S. Enteritidis, confirming once again that the growth of S. Enteritidis was affected by AHL metabolized by other bacteria and the complexity of bacterial communication.

scholarly journals Quorum-sensing regulation in rhizobia and its role in symbiotic interactions with legumes

2007 ◽  
Vol 362 (1483) ◽  
pp. 1149-1163 ◽  
Author(s):  
Maria Sanchez-Contreras ◽  
Wolfgang D Bauer ◽  
Mengsheng Gao ◽  
Jayne B Robinson ◽  
J Allan Downie
Keyword(s):  
Quorum Sensing ◽  
Potential Role ◽  
Active Role ◽  
Dependent Manner ◽  
Homoserine Lactones ◽  
Signalling Molecules ◽  
Sensing Systems ◽  
Symbiotic Interactions ◽  
Regulatory Systems

Legume-nodulating bacteria (rhizobia) usually produce N -acyl homoserine lactones, which regulate the induction of gene expression in a quorum-sensing (or population-density)-dependent manner. There is significant diversity in the types of quorum-sensing regulatory systems that are present in different rhizobia and no two independent isolates worked on in detail have the same complement of quorum-sensing genes. The genes regulated by quorum sensing appear to be rather diverse and many are associated with adaptive aspects of physiology that are probably important in the rhizosphere. It is evident that some aspects of rhizobial physiology related to the interaction between rhizobia and legumes are influenced by quorum sensing. However, it also appears that the legumes play an active role, both in terms of interfering with the rhizobial quorum-sensing systems and responding to the signalling molecules made by the bacteria. In this article, we review the diversity of quorum-sensing regulation in rhizobia and the potential role of legumes in influencing and responding to this signalling system.

scholarly journals Quorum Sensing in the Context of Food Microbiology

2012 ◽  
Vol 78 (16) ◽  
pp. 5473-5482 ◽  
Author(s):  
Panagiotis N. Skandamis ◽  
George-John E. Nychas
Keyword(s):  
Food Safety ◽  
Quorum Sensing ◽  
Communication Systems ◽  
Cell Communication ◽  
Food Preservation ◽  
Food Microbiology ◽  
Limited Information ◽  
Food Spoilage ◽  
The Many

ABSTRACTFood spoilage may be defined as a process that renders a product undesirable or unacceptable for consumption and is the outcome of the biochemical activity of a microbial community that eventually dominates according to the prevailing ecological determinants. Although limited information are reported, this activity has been attributed to quorum sensing (QS). Consequently, the potential role of cell-to-cell communication in food spoilage and food safety should be more extensively elucidated. Such information would be helpful in designing approaches for manipulating these communication systems, thereby reducing or preventing, for instance, spoilage reactions or even controlling the expression of virulence factors. Due to the many reports in the literature on the fundamental features of QS, e.g., chemistry and definitions of QS compounds, in this minireview, we only allude to the types and chemistry of QS signaling moleculesper seand to the (bioassay-based) methods of their detection and quantification, avoiding extensive documentation. Conversely, we attempt to provide insights into (i) the role of QS in food spoilage, (ii) the factors that may quench the activity of QS in foods and review the potential QS inhibitors that might “mislead” the bacterial coordination of spoilage activities and thus may be used as biopreservatives, and (iii) the future experimental approaches that need to be undertaken in order to explore the “gray” or “black” areas of QS, increase our understanding of how QS affects microbial behavior in foods, and assist in finding answers as to how we can exploit QS for the benefit of food preservation and food safety.

scholarly journals LC-MS-Based Metabolic Fingerprinting of Aqueous Humor

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Karolina Pietrowska ◽  
Diana Anna Dmuchowska ◽  
Paulina Samczuk ◽  
Tomasz Kowalczyk ◽  
Pawel Krasnicki ◽  
...  
Keyword(s):  
Aqueous Humor ◽  
Metabolic Pathways ◽  
Molecular Mechanisms ◽  
Potential Role ◽  
Global Analysis ◽  
Eye Diseases ◽  
Microbial Metabolites ◽  
Ocular Diseases ◽  
Analytical Platforms

Aqueous humor (AH) is a transparent fluid which fills the anterior and posterior chambers of the eye. It supplies nutrients and removes metabolic waste from avascular tissues in the eye. Proper homeostasis of AH is required to maintain adequate intraocular pressure as well as optical and refractive properties of the eye. Application of metabolomics to study human AH may improve knowledge about the molecular mechanisms of eye diseases. Until now, global analysis of metabolites in AH has been mainly performed using NMR. Among the analytical platforms used in metabolomics, LC-MS allows for the highest metabolome coverage. The aim of this study was to develop a method for extraction and analysis of AH metabolites by LC-QTOF-MS. Different protocols for AH preparation were tested. The best results were obtained when one volume of AH was mixed with one volume of methanol : ethanol (1 : 1). In the final method, 2 µL of extracted sample was analyzed by LC-QTOF-MS. The method allowed for reproducible measurement of over 1000 metabolic features. Almost 250 metabolites were identified in AH and assigned to 47 metabolic pathways. This method is suitable to study the potential role of amino acids, lipids, oxidative stress, or microbial metabolites in development of ocular diseases.

scholarly journals The diversity of molecular mechanisms of carbonate biomineralization by bacteria

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Sigrid Görgen ◽  
Karim Benzerara ◽  
Fériel Skouri-Panet ◽  
Muriel Gugger ◽  
Franck Chauvat ◽  
...  
Keyword(s):  
Metabolic Activity ◽  
Metabolic Pathways ◽  
Molecular Mechanisms ◽  
Organic Molecules ◽  
Good Knowledge ◽  
Engineering Applications ◽  
Geochemical Cycles ◽  
Different Types ◽  
The Future

AbstractAlthough biomineralization of CaCO3 is widespread in Bacteria and Archaea, the molecular mechanisms involved in this process remain less known than those used by Eukaryotes. A better understanding of these mechanisms is crucial for a broad diversity of studies including those (i) aiming at assessing the role of bacteria in the geochemical cycles of Ca and C, (ii) investigating the process of fossilization, and (iii) engineering applications using bacterially mediated CaCO3 mineralization. Different types of bacterially-mediated mineralization modes have been distinguished depending on whether they are influenced (by extracellular organic molecules), induced (by metabolic activity) or controlled (by specific genes). In the first two types, mineralization is usually extracellular, while it is intracellular for the two ascertained cases of controlled bacterial mineralization. In this review, we list a large number of cases illustrating the three different modes of bacterially-mediated CaCO3 mineralization. Overall, this shows the broad diversity of metabolic pathways, organic molecules and thereby microorganisms that can biomineralize CaCO3. Providing an improved understanding of the mechanisms involved and a good knowledge of the molecular drivers of carbonatogenesis, the increasing number of (meta)-omics studies may help in the future to estimate the significance of bacterially mediated CaCO3 mineralization.

scholarly journals Adaptation to Adversity: the Intermingling of Stress Tolerance and Pathogenesis in Enterococci

2019 ◽  
Vol 83 (3) ◽  
Author(s):  
Anthony O. Gaca ◽  
José A. Lemos
Keyword(s):  
Gastrointestinal Tract ◽  
Immune Responses ◽  
Stress Tolerance ◽  
Molecular Mechanisms ◽  
Multidrug Resistant ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Hospital Acquired Infections ◽  
Hospital Acquired

SUMMARY Enterococcus is a diverse and rugged genus colonizing the gastrointestinal tract of humans and numerous hosts across the animal kingdom. Enterococci are also a leading cause of multidrug-resistant hospital-acquired infections. In each of these settings, enterococci must contend with changing biophysical landscapes and innate immune responses in order to successfully colonize and transit between hosts. Therefore, it appears that the intrinsic durability that evolved to make enterococci optimally competitive in the host gastrointestinal tract also ideally positioned them to persist in hospitals, despite disinfection protocols, and acquire new antibiotic resistances from other microbes. Here, we discuss the molecular mechanisms and regulation employed by enterococci to tolerate diverse stressors and highlight the role of stress tolerance in the biology of this medically relevant genus.

scholarly journals Virulence of Burkholderia mallei Quorum-Sensing Mutants

2013 ◽  
Vol 81 (5) ◽  
pp. 1471-1478 ◽  
Author(s):  
Charlotte Majerczyk ◽  
Loren Kinman ◽  
Tony Han ◽  
Richard Bunt ◽  
E. Peter Greenberg
Keyword(s):  
Quorum Sensing ◽  
Homoserine Lactone ◽  
Mouse Lung ◽  
Depth Information ◽  
Acyl Homoserine Lactone ◽  
Burkholderia Mallei ◽  
Content Type ◽  
Homoserine Lactones ◽  
Acyl Homoserine Lactones

ABSTRACTManyProteobacteriause acyl-homoserine lactone-mediated quorum-sensing (QS) to activate specific sets of genes as a function of cell density. QS often controls the virulence of pathogenic species, and in fact a previous study indicated that QS was important forBurkholderia malleimouse lung infections. To gain in-depth information on the role of QS inB. malleivirulence, we constructed and characterized a mutant ofB. malleistrain GB8 that was unable to make acyl-homoserine lactones. The QS mutant showed virulence equal to that of its wild-type parent in an aerosol mouse infection model, and growth in macrophages was indistinguishable from that of the parent strain. Furthermore, we assessed the role of QS inB. malleiATCC 23344 by constructing and characterizing a mutant strain producing AiiA, a lactonase enzyme that degrades acyl-homoserine lactones. Although acyl-homoserine lactone levels in cultures of this strain are very low, it showed full virulence. Contrary to the previous report, we conclude that QS is not required for acuteB. malleiinfections of mice. QS may be involved in some stage of chronic infections in the natural host of horses, or the QS genes may be remnants of the QS network inB. pseudomalleifrom which this host-adapted pathogen evolved.

Insights into the Role of Quorum Sensing in Food Spoilage

2008 ◽  
Vol 71 (7) ◽  
pp. 1510-1525 ◽  
Author(s):  
MOHAMMED SALIM AMMOR ◽  
CHRISTOS MICHAELIDIS ◽  
GEORGE-JOHN E. NYCHAS
Keyword(s):  
Quorum Sensing ◽  
Enzymatic Activity ◽  
Potential Role ◽  
Cell Communication ◽  
Signaling Molecules ◽  
Food Spoilage ◽  
Associated Bacteria ◽  
Quorum Sensing Inhibitors ◽  
Detection And Quantification

Food spoilage is a consequence of the degrading enzymatic activity of some food-associated bacteria. Several proteolytic, lipolytic, chitinolytic, and pectinolytic activities associated with the deterioration of goods are regulated by quorum sensing, suggesting a potential role of such cell-to-cell communication in food spoilage. Here we review quorum sensing signaling molecules and methods of their detection and quantification, and we provide insights into the role of quorum sensing in food spoilage and address potential quorum sensing inhibitors that might be used as biopreservatives.

scholarly journals Genome-Wide Identification and Expression Analysis of the Plant U-Box Protein Gene Family in Phyllostachys edulis

2021 ◽  
Vol 12 ◽  
Author(s):  
Jie Zhou ◽  
Yaping Hu ◽  
Jiajia Li ◽  
Zhaoyan Yu ◽  
Qirong Guo
Keyword(s):  
Ubiquitin Ligase ◽  
Low Temperatures ◽  
Molecular Mechanisms ◽  
Protein Gene ◽  
Plant Stress ◽  
Phyllostachys Edulis ◽  
Genome Wide ◽  
Insight Into

The U-box gene encodes a ubiquitin ligase that contains a U-box domain. The plant U-box (PUB) protein plays an important role in the plant stress response; however, very few studies have investigated the role of these proteins in Moso bamboo (Phyllostachys edulis). Thus, more research on PUB proteins is necessary to understand the mechanisms of stress tolerance in P. edulis. In this study, we identified 121 members of the PUB family in P. edulis (PePUB), using bioinformatics based on the P. edulis V2 genome build. The U-box genes of P. edulis showed an uneven distribution among the chromosomes. Phylogenetic analysis of the U-box genes between P. edulis and Arabidopsis thaliana suggested that these genes can be classified into eight subgroups (Groups I–VIII) based on their structural and phylogenetic features. All U-box genes and the structure of their encoded proteins were identified in P. edulis. We further investigated the expression pattern of PePUB genes in different tissues, including the leaves, panicles, rhizomes, roots, and shoots. The qRT-PCR results showed that expression of three genes, PePUB15, PePUB92, and PePUB120, was upregulated at low temperatures compared to that at 25°C. The expression levels of two PePUBs, PePUB60 and PePUB120, were upregulated under drought stress. These results suggest that the PePUB genes play an important role in resistance to low temperatures and drought in P. edulis. This research provides new insight into the function, diversity, and characterization of PUB genes in P. edulis and provides a basis for understanding their biological roles and molecular mechanisms.

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