14 research outputs found

    INCUMBENT’S DIGITAL TRANSFORMATION: A MULTI-DISCIPLINARY AND PARADOXICAL PERSPECTIVE

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    Digital transformation (DT) is a major challenge for incumbent organisations with an astonishing failure rate. We review digital transformation in established, old, large, and incumbent organisations adopting a Structured and Computational Literature Review (SLR and CLR). We employ a machine learning algorithm (LDA) to inspect the topics discussed in 103 peer-reviewed studies published between 2010 and 2022 in the fields of Information Management, Innovation Management, Operation Management, Strategic Management and General Management. We extract and discuss the top-five key topics emerging from the studies to understand the state-of-the-art literature on DT in established firms. Then, we advance paradox thinking as a lens to study DT in incumbent settings. We contribute to the DT discourse by providing a multidisciplinary review of the current trends on the topic of DT of in-cumbent firms; moreover, we contribute by advancing paradox thinking as a novel lens to study DT in incumbent organisations, further proposing research questions and avenues; finally, we propose managerial insights in line with paradox thinking to create momentum and thrive as DT champions

    High-throughput DNA sequencing to survey bacterial histidine and tyrosine decarboxylases in raw milk cheeses

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    peer-reviewedBackground The aim of this study was to employ high-throughput DNA sequencing to assess the incidence of bacteria with biogenic amine (BA; histamine and tyramine) producing potential from among 10 different cheeses varieties. To facilitate this, a diagnostic approach using degenerate PCR primer pairs that were previously designed to amplify segments of the histidine (hdc) and tyrosine (tdc) decarboxylase gene clusters were employed. In contrast to previous studies in which the decarboxylase genes of specific isolates were studied, in this instance amplifications were performed using total metagenomic DNA extracts. Results Amplicons were initially cloned to facilitate Sanger sequencing of individual gene fragments to ensure that a variety of hdc and tdc genes were present. Once this was established, high throughput DNA sequencing of these amplicons was performed to provide a more in-depth analysis of the histamine- and tyramine-producing bacteria present in the cheeses. High-throughput sequencing resulted in generation of a total of 1,563,764 sequencing reads and revealed that Lactobacillus curvatus, Enterococcus faecium and E. faecalis were the dominant species with tyramine producing potential, while Lb. buchneri was found to be the dominant species harbouring histaminogenic potential. Commonly used cheese starter bacteria, including Streptococcus thermophilus and Lb. delbreueckii, were also identified as having biogenic amine producing potential in the cheese studied. Molecular analysis of bacterial communities was then further complemented with HPLC quantification of histamine and tyramine in the sampled cheeses. Conclusions In this study, high-throughput DNA sequencing successfully identified populations capable of amine production in a variety of cheeses. This approach also gave an insight into the broader hdc and tdc complement within the various cheeses. This approach can be used to detect amine producing communities not only in food matrices but also in the production environment itself.This work was funded by the Department of Agriculture, Food and the Marine under the Food Institutional Research Measure through the ‘Cheeseboard 2015’ project. Daniel J. O’Sullivan is in receipt of a Teagasc Walsh Fellowship, Grant Number: 2012205

    Insights into the Mode of Action of the Sactibiotic Thuricin CD

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    peer-reviewedThuricin CD is a two-component bacteriocin, consisting of the peptides Trnα and Trnβ, and belongs to the newly designated sactibiotic subclass of bacteriocins. While it is clear from studies conducted thus far that it is a narrow-spectrum bacteriocin, requiring the synergistic activity of the two peptides, the precise mechanism of action of thuricin CD has not been elucidated. This study used a combination of flow cytometry and traditional culture-dependent assays to ascertain the effects of the thuricin CD peptides on the morphology, physiology and viability of sensitive Bacillus firmus DPC6349 cells. We show that both Trnα and Trnβ are membrane-acting and cause a collapse of the membrane potential, which could not be reversed even under membrane-repolarizing conditions. Furthermore, the depolarizing action of thuricin CD is accompanied by reductions in cell size and granularity, producing a pattern of physiological alterations in DPC6349 cells similar to those triggered by the pore-forming single-component bacteriocin Nisin A, and two-component lacticin 3147. Taken together, these results lead us to postulate that the lytic activity of thuricin CD involves the insertion of thuricin CD peptides into the membrane of target cells leading to permeabilization due to pore formation and consequent flux of ions across the membrane, resulting in membrane depolarization and eventual cell death.HM is a researcher in Teagasc Food Research Centre and the Alimentary Pharmabiotic Centre Microbiome Institute, funded by the Science Foundation of Ireland (SFI)-funded Centre for Science, Engineering and Technology and the Alimentary Pharmabiotic Centre Microbiome Institute (APC) Grant Number SFI/12/RC/2273. Research in PC, CH, MR, VF, and RR laboratories is supported by the Science Foundation of Ireland (SFI)-funded Centre for Science, Engineering and Technology and the APC Microbiome Institute

    Next-generation multiparameter flow cytometry assay improves the assessment of oxidative stress in probiotics

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    peer-reviewedStability of probiotic products’ potency throughout shelf life is essential to ensure systematic delivery of the dosages required to provide clinically-proven health benefits. Due to the oxygen sensitivity of gut-derived microorganisms, methods for the rapid and accurate monitoring of oxidative stress in probiotics are greatly needed as they can be instrumental to both bioprocess optimization and quality control. This study introduces a next-generation flow cytometry method multiplexing the CellROX® Green and Propidium Iodide probes for the simultaneous measurement of free total reactive oxygen species (ROS) and membrane integrity, respectively. The multiparameter method was compared to the single-parameter assays, measuring either ROS or membrane integrity, for the ability to evaluate the fitness of Lactobacillus rhamnosus GG (LGG) after freeze drying, spray drying and H2O2-mediated oxidative stress. Each stand-alone assay detected only three cell populations, showing either differential membrane integrity (Syto 24+/PI-, Syto 24+/PI+, Syto 24-/PI+) or ROS levels (ROS-, low-ROS, high-ROS), and no correlation could be drawn between these groups. Conversely, the multiparameter method detected up to five physiologically distinct cell populations and allowed the integrated assessment of their membrane integrity and oxidative stress. It also revealed a much larger fitness heterogeneity in LGG as each group of low-ROS and high-ROS cells was found to be formed by a healthier population with an intact membrane (L-ROS/PI-, H-ROS/PI-) and a population with damaged membrane (L-ROS/PI+, H-ROS/PI+). As the CRG probe only detects free unreacted ROS, these populations are suggested to reflect the dynamic lifecycle of ROS formation, accumulation and reactive depletion leading to oxidative damage of macromolecules and consequent cell death. With the stand-alone CRG assay being unable to detect ROS lifecycle, the multiparameter method here presented delivers a superior profiling of the heterogeneity generated by oxidative stress in bacteria and enables a more correct interpretation of CRG fluorescence data. We provide recent examples from literature where the use of a single-parameter fluorescence approach may have led to misinterpret oxidative stress data and eventually draw erroneous conclusions

    Insights into the Mode of Action of the Sactibiotic Thuricin CD

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    Thuricin CD is a two-component bacteriocin, consisting of the peptides Trnα and Trnβ, and belongs to the newly designated sactibiotic subclass of bacteriocins. While it is clear from studies conducted thus far that it is a narrow-spectrum bacteriocin, requiring the synergistic activity of the two peptides, the precise mechanism of action of thuricin CD has not been elucidated. This study used a combination of flow cytometry and traditional culture-dependent assays to ascertain the effects of the thuricin CD peptides on the morphology, physiology and viability of sensitive Bacillus firmus DPC6349 cells. We show that both Trnα and Trnβ are membrane-acting and cause a collapse of the membrane potential, which could not be reversed even under membrane-repolarizing conditions. Furthermore, the depolarizing action of thuricin CD is accompanied by reductions in cell size and granularity, producing a pattern of physiological alterations in DPC6349 cells similar to those triggered by the pore-forming single-component bacteriocin Nisin A, and two-component lacticin 3147. Taken together, these results lead us to postulate that the lytic activity of thuricin CD involves the insertion of thuricin CD peptides into the membrane of target cells leading to permeabilization due to pore formation and consequent flux of ions across the membrane, resulting in membrane depolarization and eventual cell death

    Plasmid biology of natural Lactococcus lactis strains and molecular mechanisms of bacteriophage-host interaction

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    Lacticin 3147, enterocin AS-48, lacticin 481, variacin, and sakacin P are bacteriocins offering promising perspectives in terms of preservation and shelf-life extension of food products and should find commercial application in the near future. The studies detailing their characterization and bio-preservative applications are reviewed. Transcriptomic analyses showed a cell wall-targeted response of Lactococcus lactis IL1403 during the early stages of infection with the lytic bacteriophage c2, which is probably orchestrated by a number of membrane stress proteins and involves D-alanylation of membrane lipoteichoic acids, restoration of the physiological proton motive force disrupted following bacteriophage infection, and energy conservation. Sequencing of the eight plasmids of L. lactis subsp. cremoris DPC3758 from raw milk cheese revealed three anti-phage restriction/modification (R/M) systems, immunity/resistance to nisin, lacticin 481, cadmium and copper, and six conjugative/mobilization regions. A food-grade derivative strain with enhanced bacteriophage resistance was generated via stacking of R/M plasmids. Sequencing and functional analysis of the four plasmids of L. lactis subsp. lactis biovar. diacetylactis DPC3901 from raw milk cheese revealed genes novel to Lactococcus and typical of bacteria associated with plants, in addition to genes associated with plant-derived lactococcal strains. The functionality of a novel high-affinity regulated system for cobalt uptake was demonstrated. The bacteriophage resistant and bacteriocin-producing plasmid pMRC01 places a metabolic burden on lactococcal hosts resulting in lowered growth rates and increased cell permeability and autolysis. The magnitude of these effects is strain dependent but not related to bacteriocin production. Starters’ acidification capacity is not significantly affected. Transcriptomic analyses showed that pMRC01 abortive infection (Abi) system is probably subjected to a complex regulatory control by Rgg-like ORF51 and CopG-like ORF58 proteins. These regulators are suggested to modulate the activity of the putative Abi effectors ORF50 and ORF49 exhibiting topology and functional similarities to the Rex system aborting bacteriophage λ lytic growth

    Redefining the effect of salt on thermophilic starter cell viability, culturability and metabolic activity in cheese

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    This study investigated the differential effect of salt concentration in the outside and inside layers of brine salted cheeses on viability, culturability and enzyme activity of starter bacteria. The high-salt environment of the outside layer caused a sharp decrease in L. helveticus viability as measured by traditional plate counts. Remarkably, this was associated with lower release of intracellular enzymes (LDH), reduced levels of proteolysis and larger membrane integrity as measured by flow cytometry (FC) following classical Live/Dead staining. FC analysis of light scattering properties highlighted a significant reduction in size and granularity of the microbiota located in the cheese surface, suggestive of cell shrinkage and condensation of internal macromolecules probably due to hyperosmotic stress. The microbiota of the cheese surface were found to experience greater oxidative stress, as measured by FC analysis of the total levels of reactive oxygen species, compared to that of the interior layer. These results lead us to postulate that the physiology and health status of the microbiota were significantly different in the outer and inner layers of the cheese. The hyperosmotic environment of the outer layer resulted in reduced cell lysis, as measurable by assays based upon membrane integrity, but rather triggered cell death via mechanisms involving cell shrinkage and ROS-mediated damage of vital intracellular components. This study challenges the current thinking on how salt controls microbial activity in ripening cheese, especially in cheeses which are brine salted as local variations in biochemical ripening indices can differ significantly from the outside to the inside of a ripening cheese

    The effect of different technologies in Pomegranate jam preparation on the phenolic compounds, vitamin C and antioxidant activity

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    The effect of different gelling agents and processing for jam production from pomegranate juice was evaluated. In the last years, different gelling agents were tested for improving jam quality in terms of color and bioactive compounds. The unsonicated and sonicated pomegranate juices were processed for jam production by micro waves, under vacuum and cryoconcentration concentration methods using low and high methoxy pectins, and carob seed flour as gelling agents. The polyphenols content of sonicated jam was significantly lower than unsonicated samples and cryoconcentrated jams showed the significantly highest value among other methods. The results showed the highest anthocyanin content in the both sonicated and unsonicated jam including carob seed flour and antocyanins content of the cryoconcentrated samples was in the range of 156.6–186.2 mg/kg, and revealed higher content compared to the other processed samples. The findings showed that cryoconcentrated method is more effective in preserving the total polyphenols, anthocyanins, vitamin C and antioxidant activity. Moreover, also the colour of cryoconcentrated pomegranade jam was preserved. Cryoconcentration is a promising method for preserving organoleptic and functional prop erties of the jam produced from pomegranate juice

    Additional file 1: of High-throughput DNA sequencing to survey bacterial histidine and tyrosine decarboxylases in raw milk cheeses

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    Table S1. Standards preparation for HPLC analysis of individual biogenic amines. Table S2. Complete BLAST analysis of clones subjected to Sanger sequencing. Table S3. Table S2: Complete BLAST analysis of tdc clones subjected to Sanger sequencing. Table S4. Total reads assigned for each cheese. Table S5a/b. Microbial composition of bacteria at phylum, order, genus and species levels. Figure S6. Microbial composition at Genus and Species levels. (DOCX 62 kb
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