Now showing items 1-20 of 328

    • Marine Functional Foods Research Initiative (NutraMara)

      Troy, Declan; Tiwari, Brijesh; Hayes, Maria; Ross, R. Paul; Stanton, Catherine; Johnson, Mark; Stengel, Dagmar; O'Doherty, John V.; Fitzgerald, Richard J.; McSorley, Emeir; Kerry, Joseph; Marine Institute; MFFRI/07/01 (Marine Institute, 2017-12)
      The NutraMara – Marine Functional Foods Research Initiative was conceived by Sea Change - A Marine Knowledge, Research and Innovation Strategy for Ireland 2007-2013. The goal was to develop a collaborative funding mechanism that would create new research capacity and build the capabilities required to maximise the potential of Ireland’s extensive marine bioresources. By supporting a strong interdisciplinary research team, capable of exploring marine animals and plants as a sustainable source of materials for use as functional ingredients and foods, the vision for NutraMara was to position Ireland to the fore in use of marine bioresources as health beneficial ingredients. Commencing in 2008 and supported by funds of €5.2 million from the Marine Institute and the Department of Agriculture, Food and the Marine, the research programme was led by Teagasc as the head of a multi-institutional consortium. The NutraMara consortium comprises marine bioresources and bioscience expertise, with food science and technology expertise from University College Cork; University College Dublin; the National University of Ireland Galway; the University of Limerick and Ulster University. Research effort was directed towards exploring Ireland’s marine bioresources – including macro- and microalgae, finfish and shellfish from wild and cultured sources: and discards from processing fish as sources of novel ingredients with bioactive characteristics. This discovery activity involved the collection of over 600 samples from 39 species of algae and fish and the analysis of 5,800 extracts, which resulted in 3,000 positive “hits” for bioactivity. The NutraMara consortium has built a strong research capacity to identify, characterise and evaluate marine-origin bioactives for use as/in functional foods. It further built the capacity to develop model foods enhanced with these marine-origin functional ingredients; providing insights to the processing challenges associated with producing functional ingredients from marine organisms. The consortium was actively engaged in research activities designed to identify and assess bioactive compounds from available marine resources, including polyphenols, proteins/peptides, amino acids, polysaccharides, polyunsaturated fatty acids and materials with antioxidant, probiotic or prebiotic properties. A key component of NutraMara’s activities was the development of human capital. The recruitment of M.Sc. and PhD students and their integration within a dynamic research environment that has strong links to industry, provided lasting expertise and capabilities, which are relevant to the needs of Ireland’s food and marine sectors. NutraMara research led to the awarding of eighteen PhDs and recruitment of 21 post-doctoral researchers over the eight year research programme. In excess of 80 peer reviewed publications resulted from this research and more publications are planned. A further 100 posters and conference presentations were also delivered by NutraMara researchers and Principal Investigators. The development and implementation of training and exchange programmes aimed at providing early stage researchers with inter-disciplinary skills that are critical to their development as researchers, enhanced the research capacity of institutions, the industry sectors and the country as a whole. Principal Investigators involved in leading the NutraMara research programme have secured additional research grants of almost €6 million from national and international sources and are engaged in extensive research collaboration involving marine and food research expertise; an activity which did not exist prior to NutraMara. The dissemination of knowledge and transfer of research results to industry were key activities in the research programme. The research outputs and visibility of NutraMara activity nationally resulted in 10 companies engaging in research and development activity with the consortium. Regular workshops and conferences organised by NutraMara attracted close to five hundred participants from Ireland and overseas. Members of the NutraMara core PI group have contributed to the formulation of new national foods and marine research policy and national research agenda, both during the national prioritisation exercise and in sectoral research strategies. This final project report describes the process by which research targets were identified, and the results of extensive screening and evaluation of compounds extracted from marine bioresources. It also highlights the development of new protocols designed to extract compounds in ways that are food friendly. Evaluating the functional properties, bioactivity and bioavailability of high potential marine compounds involved in vitro and in vivo testing. Pilot animal and human intervention studies yielded further insight to the potential and challenges in developing marine functional ingredients. As a result of work completed within the NutraMara consortium, Ireland is well positioned to continue to contribute to the development of ingredients derived from marine organisms and in doing so support the on-going development of Ireland’s food sector.
    • Microbiota-related Changes in Bile Acid & Tryptophan Metabolism are Associated with Gastrointestinal Dysfunction in a Mouse Model of Autism

      Golubeva, Anna B.; Joyce, Susan A.; Moloney, Gerard; Burokas, Aurelijus; Sherwin, Eoin; Arboyelaya, Silvia; Flynn, Ian; Khochanskiy, Dmitry; Pérez, Angela M.; Peterson, Veronica; REa, Kieran; MUrphy, Kiera; Makarova, Olga; Buravkov, Sergey; Hyland, Niall P.; Stanton, Catherine; Clarke, Gerard; Gahan, Cormac G>M>; Dinan, Timothy G.; Cryan, John F.; Science Foundation Ireland; SFI/12/RC/2273 (2017-09-15)
      Autism spectrum disorder (ASD) is one of the most prevalent neurodevelopmental conditions worldwide. There is growing awareness that ASD is highly comorbid with gastrointestinal distress and altered intestinal microbiome, and that host-microbiome interactions may contribute to the disease symptoms. However, the paucity of knowledge on gut-brain axis signaling in autism constitutes an obstacle to the development of precision microbiota-based therapeutics in ASD. To this end, we explored the interactions between intestinal microbiota, gut physiology and social behavior in a BTBR T+ Itpr3tf/J mouse model of ASD. Here we show that a reduction in the relative abundance of very particular bacterial taxa in the BTBR gut – namely, bile-metabolizing Bifidobacterium and Blautia species, - is associated with deficient bile acid and tryptophan metabolism in the intestine, marked gastrointestinal dysfunction, as well as impaired social interactions in BTBR mice. Together these data support the concept of targeted manipulation of the gut microbiota for reversing gastrointestinal and behavioral symptomatology in ASD, and offer specific plausible targets in this endeavor.
    • A Review on the Applications of Next Generation Sequencing Technologies as Applied to Food-Related Microbiome Studies

      CaoYu; Fanning, Seamus; Proos, Sinead; Jordan, Kieran; Srikumar, Shabarinath; Department of Agriculture, Food and the Marine; SMART-PIF; 13/F/423 (Frontiers, 2017)
      The development of next generation sequencing (NGS) techniques has enabled researchers to study and understand the world of microorganisms from broader and deeper perspectives. The contemporary advances in DNA sequencing technologies have not only enabled finer characterization of bacterial genomes but also provided deeper taxonomic identification of complex microbiomes which in its genomic essence is the combined genetic material of the microorganisms inhabiting an environment, whether the environment be a particular body econiche (e.g., human intestinal contents) or a food manufacturing facility econiche (e.g., floor drain). To date, 16S rDNA sequencing, metagenomics and metatranscriptomics are the three basic sequencing strategies used in the taxonomic identification and characterization of food-related microbiomes. These sequencing strategies have used different NGS platforms for DNA and RNA sequence identification. Traditionally, 16S rDNA sequencing has played a key role in understanding the taxonomic composition of a food-related microbiome. Recently, metagenomic approaches have resulted in improved understanding of a microbiome by providing a species-level/strain-level characterization. Further, metatranscriptomic approaches have contributed to the functional characterization of the complex interactions between different microbial communities within a single microbiome. Many studies have highlighted the use of NGS techniques in investigating the microbiome of fermented foods. However, the utilization of NGS techniques in studying the microbiome of non-fermented foods are limited. This review provides a brief overview of the advances in DNA sequencing chemistries as the technology progressed from first, next and third generations and highlights how NGS provided a deeper understanding of food-related microbiomes with special focus on non-fermented foods.
    • Stabilising effect of α-lactalbumin on concentrated infant milk formula emulsions heat treated pre- or post-homogenisation

      Buggy, Aoife K.; McManus, Jenifer J.; Brodkorb, Andre; McCarthy, Noel; Fenelon, Mark A. (Springer, 2016-11-22)
      Protein type and/or heat treatment pre- or post-homogenisation can affect the physical stability of infant formulations during manufacture. Previous research has described the use of α-lactalbumin addition in infant formulae, but has not demonstrated the effect of heating pre- or post-emulsion formulation during processing. The objective of this study was to evaluate the effect of both of these parameters. Three batches of model 1st-stage infant formula containing differing whey protein ratios (60:40 whey: casein with α-lactalbumin content 12, 30 or 48% of total protein) were prepared. Each batch was split; one half receiving heat treatment pre-homogenisation and the second half homogenised and then heat treated. Emulsion stability was determined by size exclusion chromatography, SDS-PAGE, particle size and viscosity measurements. There was a significant (P < 0.05) reduction in the formation of large soluble aggregates upon increasing α-lac concentration in emulsions heat treated either before or after homogenisation. Heat treatment of formulations post-homogenisation resulted in a higher (P < 0.05) D.v09 within the particle size distribution; increasing α-lactalbumin concentration to 30 or 48% significantly (P < 0.05) reduced the D.v09 within the particle size distribution in these emulsions. The viscosity of concentrates (55 % total solids) containing the 12% α-lactalbumin, heat treated post-homogenisation, was significantly greater (P < 0.05) than the equivalent emulsion heat treated pre-homogenisation; increasing the α-lactalbumin concentration to 30 or 48% significantly (P < 0.05) reduced viscosity. When the α-lactalbumin content was increased to 48% as a percentage of the total protein, heating before or after emulsion formation had no effect on concentrate viscosity. The findings demonstrate the importance of thermal denaturation/aggregation of whey proteins (and in particular, the ratio of α-lactalbumin to β-lactoglobulin) prior to homogenisation of infant formula emulsions.
    • Insights into the Mode of Action of the Sactibiotic Thuricin CD

      Mathur, Harsh; Fallico, Vicenzo; O'Connor, Paula M.; Rea, Mary C.; Cotter, Paul D.; Hill, Colin; Ross, R. Paul (Frontiers, 2017-04-20)
      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.
    • Genome-wide association analysis and functional annotation of positional candidate genes for feed conversion efficiency and growth rate in pigs

      Horodyska, Justyna; Hamill, Ruth M.; Varley, Patrick F.; Wimmers, Klaus (PLOS, 2017-06-12)
      Feed conversion efficiency is a measure of how well an animal converts feed into live weight and it is typically expressed as feed conversion ratio (FCR). FCR and related traits like growth rate (e.g. days to 110 kg—D110) are of high interest for animal breeders, farmers and society due to implications on animal performance, feeding costs and environmental sustainability. The objective of this study was to identify genomic regions associated with FCR and D110 in pigs. A total of 952 terminal line boars, showing an individual variation in FCR, were genotyped using 60K SNP-Chips. Markers were tested for associations with estimated breeding values (EBV) for FCR and D110. For FCR, the largest number of associated SNPs was located on chromosomes 4 (30 SNPs), 1 (25 SNPs), X (15 SNPs) and 6 (12 SNPs). The most prominent genomic regions for D110 were identified on chromosomes 15 (10 SNPs), 1 and 4 (both 9 SNPs). The most significantly associated SNPs for FCR and D110 mapped 129.8 Kb from METTL11B (chromosome 4) and 32Kb from MBD5 (chromosome 15), respectively. A list of positional genes, closest to significantly associated SNPs, was used to identify enriched pathways and biological functions related to the QTL for both traits. A number of candidate genes were significantly overrepresented in pathways of immune cell trafficking, lymphoid tissue structure, organ morphology, endocrine system function, lipid metabolism, and energy production. After resequencing the coding region of selected positional and functional candidate genes, six SNPs were genotyped in a subset of boars. SNPs in PRKDC, SELL, NR2E1 and AKRIC3 showed significant associations with EBVs for FCR/D110. The study revealed a number of chromosomal regions and candidate genes affecting FCR/D110 and pointed to corresponding biological pathways related to lipid metabolism, olfactory reception, and also immunological status.
    • Controlling Blown Pack Spoilage Using Anti-Microbial Packaging

      Reid, Rachael; Bolton, Declan; Tiuftin, Andrey; Kerry, Joe P.; Fanning, Seamus; Whyte, Paul (MDPI, 2017-08-12)
      Active (anti-microbial) packaging was prepared using three different formulations; Auranta FV; Inbac-MDA and sodium octanoate at two concentrations (2.5 and 3.5 times their minimum inhibitory concentration (MIC, the lowest concentration that will inhibit the visible growth of the organisms) against Clostridium estertheticum, DSMZ 8809). Inoculated beef samples were packaged using the active packaging and monitored for 100 days storage at 2 °C for blown pack spoilage. The time to the onset of blown pack spoilage was significantly (p < 0.01) increased using Auranta FV and sodium octanoate (caprylic acid sodium salt) at both concentrations. Moreover, sodium octanoate packs had significantly (p < 0.01) delayed blown pack spoilage as compared to Auranta FV. It was therefore concluded that Auranta FV or sodium octanoate, incorporated into the packaging materials used for vacuum packaged beef, would inhibit blown pack spoilage and in the case of the latter, well beyond the 42 days storage period currently required for beef primals
    • Genome Sequence of Staphylococcus saprophyticus DPC5671, a Strain Isolated from Cheddar Cheese

      Bertuzzi, Andrea; Guinane, Caitriona M.; Crispie, Fiona; Kilcawley, Kieran N; McSweeney, Paul L.H.; Rea, Mary C. (American Society for Microbiology, 2017-04-20)
      The draft genome sequence of Staphylococcus saprophyticus DPC5671, isolated from cheddar cheese, was determined. S. saprophyticus is a common Gram-positive bacterium detected on the surface of smear-ripened cheese and other fermented foods.
    • Algal Proteins: Extraction, Application, and Challenges Concerning Production

      Bleakley, Stephen; Hayes, Maria (MDPI, 2017-04-26)
      Population growth combined with increasingly limited resources of arable land and fresh water has resulted in a need for alternative protein sources. Macroalgae (seaweed) and microalgae are examples of under-exploited “crops”. Algae do not compete with traditional food crops for space and resources. This review details the characteristics of commonly consumed algae, as well as their potential for use as a protein source based on their protein quality, amino acid composition, and digestibility. Protein extraction methods applied to algae to date, including enzymatic hydrolysis, physical processes, and chemical extraction and novel methods such as ultrasound-assisted extraction, pulsed electric field, and microwave-assisted extraction are discussed. Moreover, existing protein enrichment methods used in the dairy industry and the potential of these methods to generate high value ingredients from algae, such as bioactive peptides and functional ingredients are discussed. Applications of algae in human nutrition, animal feed, and aquaculture are examined
    • Simulated gastrointestinal digestion of nisin and interaction between nisin and bile

      Gough, Ronan; O'Connor, Paula M.; Rea, Mary C.; Gomez-Sal, Beatriz; Miao, Song; Hill, Colin; Brodkorb, Andre (Elsevier, 2017-08-14)
      Nisin, an antimicrobial peptide showing activity against many Gram positive bacteria, is widely used as a food preservative. The simulated gastrointestinal digestion of nisin (variant A) was studied using the in vitro INFOGEST digestion method. Following oral, gastric and small intestinal digestion, there was no intact nisin in the system and the nisin was primarily digested by pancreatin. After digestion, six nisin fragments (1–11, 1–12, 1–20, 1–21, 1–29 and 1–32) were identified by reversed phase high performance liquid chromatography and mass spectroscopy and four of these nisin fragments (1–20, 1–21, 1–29 and 1–32) demonstrated low antibacterial activity against Lactococcus lactis HP in agar diffusion activity assays. Additionally, it was observed that bile salts form a complex with nisin. This was examined by atomic force microscopy, turbidity and dynamic light scattering, which showed that this interaction resulted in significantly larger bile salt micelles. The presence of bile salts at physiological levels significantly altered the relative amounts of the nisin fragments 1–12, 1–20 and 1–29 produced during an in vitro digestion. This study highlights the importance of including bile in simulated digestions of antimicrobial peptides in order to obtain a more accurate simulation of the in vivo digestion products and their activity.
    • Isolation and characterisation of κ-casein/whey protein particles from heated milk protein concentrate and role of κ-casein in whey protein aggregation

      Gaspard, Sophie J.; Auty, Mark A.E.; Kelly, Alan L.; O'Mahony, James A.; Brodkorb, Andre (Elsevier, 2017-06-12)
      Milk protein concentrate (79% protein) reconstituted at 13.5% (w/v) protein was heated (90 °C, 25 min, pH 7.2) with or without added calcium chloride. After fractionation of the casein and whey protein aggregates by fast protein liquid chromatography, the heat stability (90 °C, up to 1 h) of the fractions (0.25%, w/v, protein) was assessed. The heat-induced aggregates were composed of whey protein and casein, in whey protein:casein ratios ranging from 1:0.5 to 1:9. The heat stability was positively correlated with the casein concentration in the samples. The samples containing the highest proportion of caseins were the most heat-stable, and close to 100% (w/w) of the aggregates were recovered post-heat treatment in the supernatant of such samples (centrifugation for 30 min at 10,000 × g). κ-Casein appeared to act as a chaperone controlling the aggregation of whey proteins, and this effect was stronger in the presence of αS- and β-casein.
    • A Simple Method for the Purification of Nisin

      Gough, Ronan; Gomez-Sala, Beatriz; O'Connor, Paula M.; Rea, Mary C.; Miao, Song; Hill, Colin; Brodkorb, Andre (Springer, 2017-05-29)
      Nisin, an antimicrobial peptide showing activity against a broad range of Gram-positive bacteria, is widely used as a food preservative and has potential as a therapeutic for a range of infectious diseases. Here, we present a simple purification method, based on a salting-out approach, which can produce a powder containing ∼33% nisin, from a nisin-producing culture in a whey permeate-based medium. This process removes over 99% of the lactic acid, NaCl, lactose and non-nisin proteins from the cell-free culture supernatant. The approach can also enrich a commonly used commercial nisin preparation over 30-fold to a purity of ∼58%. These are higher purities than comparable published methods. The simplicity of this approach facilitates its use in research and also its scale-up.
    • Bacteriocin-Antimicrobial Synergy: A Medical and Food Perspective

      Mathur, Harsh; Field, Des; Rea, Mary C.; Cotter, Paul D.; Hill, Colin; Ross, R.Paul (Frontiers, 2017-06-29)
      The continuing emergence of multi-drug resistant pathogens has sparked an interest in seeking alternative therapeutic options. Antimicrobial combinatorial therapy is one such avenue. A number of studies have been conducted, involving combinations of bacteriocins with other antimicrobials, to circumvent the development of antimicrobial resistance and/or increase antimicrobial potency. Such bacteriocin-antimicrobial combinations could have tremendous value, in terms of reducing the likelihood of resistance development due to the involvement of two distinct mechanisms of antimicrobial action. Furthermore, antimicrobial synergistic interactions may also have potential financial implications in terms of decreasing the costs of treatment by reducing the concentration of an expensive antimicrobial and utilizing it in combination with an inexpensive one. In addition, combinatorial therapies with bacteriocins can broaden antimicrobial spectra and/or result in a reduction in the concentration of an antibiotic required for effective treatments to the extent that potentially toxic or adverse side effects can be reduced or eliminated. Here, we review studies in which bacteriocins were found to be effective in combination with other antimicrobials, with a view to targeting clinical and/or food-borne pathogens. Furthermore, we discuss some of the bottlenecks which are currently hindering the development of bacteriocins as viable therapeutic options, as well as addressing the need to exercise caution when attempting to predict clinical outcomes of bacteriocin-antimicrobial combinations.
    • Whole-Genome Shotgun Sequence of Salmonella bongori, First Isolated in Northwestern Italy

      Romano, Angelo; Bellio, Alberto; Macori, Guerrino; Cotter, Paul D; Manila Bianchi, Daniela; Gallina, Silvia; Decastelli, Lucia (American Society for Microbiology, 2017-07-06)
      This study describes the whole-genome shotgun sequence of Salmonella bongori 48:z35:–, originally isolated from a 1-year-old symptomatic patient in northwest Italy, a typically nonendemic area. The draft genome sequence contained 4.56 Mbp and the G+C content was 51.27%.
    • Draft Genome Sequences of Three Lactobacillus paracasei Strains, Members of the Nonstarter Microbiota of Mature Cheddar Cheese

      Stefanovic, Ewelina; Fitzgerald, Gerald; McAuliffe, Olivia (American Society for Microbiology, 2017-07-20)
      Lactobacillus paracasei strains are common members of the nonstarter microbiota present in various types of cheeses. The draft genome sequences of three strains isolated from mature cheddar cheeses are reported here.
    • Future Protein Supply and Demand: Strategies and Factors Influencing a Sustainable Equilibrium

      Henchion, Maeve; Hayes, Maria; Mullen, Anne Maria; Fenelon, Mark; Tiwari, Brijesh; Department of Agriculture, Food and the Marine; 11/F/043 (MDPI, 2017-07-20)
      A growing global population, combined with factors such as changing socio-demographics, will place increased pressure on the world’s resources to provide not only more but also different types of food. Increased demand for animal-based protein in particular is expected to have a negative environmental impact, generating greenhouse gas emissions, requiring more water and more land. Addressing this “perfect storm” will necessitate more sustainable production of existing sources of protein as well as alternative sources for direct human consumption. This paper outlines some potential demand scenarios and provides an overview of selected existing and novel protein sources in terms of their potential to sustainably deliver protein for the future, considering drivers and challenges relating to nutritional, environmental, and technological and market/consumer domains. It concludes that different factors influence the potential of existing and novel sources. Existing protein sources are primarily hindered by their negative environmental impacts with some concerns around health. However, they offer social and economic benefits, and have a high level of consumer acceptance. Furthermore, recent research emphasizes the role of livestock as part of the solution to greenhouse gas emissions, and indicates that animal-based protein has an important role as part of a sustainable diet and as a contributor to food security. Novel proteins require the development of new value chains, and attention to issues such as production costs, food safety, scalability and consumer acceptance. Furthermore, positive environmental impacts cannot be assumed with novel protein sources and care must be taken to ensure that comparisons between novel and existing protein sources are valid. Greater alignment of political forces, and the involvement of wider stakeholders in a governance role, as well as development/commercialization role, is required to address both sources of protein and ensure food security.
    • The Fungal Frontier: A Comparative Analysis of Methods Used in the Study of the Human Gut Mycobiome

      Huseyin, Chloe E.; Cabrera Rubio, Raul; O'Sullivan, Orla; Cotter, Paul D; Scanlan, Pauline D. (Frontiers, 2017-07-31)
      The human gut is host to a diverse range of fungal species, collectively referred to as the gut “mycobiome”. The gut mycobiome is emerging as an area of considerable research interest due to the potential roles of these fungi in human health and disease. However, there is no consensus as to what the best or most suitable methodologies available are with respect to characterizing the human gut mycobiome. The aim of this study is to provide a comparative analysis of several previously published mycobiome-specific culture-dependent and -independent methodologies, including choice of culture media, incubation conditions (aerobic versus anaerobic), DNA extraction method, primer set and freezing of fecal samples to assess their relative merits and suitability for gut mycobiome analysis. There was no significant effect of media type or aeration on culture-dependent results. However, freezing was found to have a significant effect on fungal viability, with significantly lower fungal numbers recovered from frozen samples. DNA extraction method had a significant effect on DNA yield and quality. However, freezing and extraction method did not have any impact on either α or β diversity. There was also considerable variation in the ability of different fungal-specific primer sets to generate PCR products for subsequent sequence analysis. Through this investigation two DNA extraction methods and one primer set was identified which facilitated the analysis of the mycobiome for all samples in this study. Ultimately, a diverse range of fungal species were recovered using both approaches, with Candida and Saccharomyces identified as the most common fungal species recovered using culture-dependent and culture-independent methods, respectively. As has been apparent from ecological surveys of the bacterial fraction of the gut microbiota, the use of different methodologies can also impact on our understanding of gut mycobiome composition and therefore requires careful consideration. Future research into the gut mycobiome needs to adopt a common strategy to minimize potentially confounding effects of methodological choice and to facilitate comparative analysis of datasets.
    • Synergistic Nisin-Polymyxin Combinations for the Control of Pseudomonas Biofilm Formation

      Field, Des; Seisling, Nynke; Cotter, Paul D.; Ross, R. Paul; Hill, Colin (Frontiers, 2016-10-26)
      The emergence and dissemination of multi-drug resistant pathogens is a global concern. Moreover, even greater levels of resistance are conferred on bacteria when in the form of biofilms (i.e., complex, sessile communities of bacteria embedded in an organic polymer matrix). For decades, antimicrobial peptides have been hailed as a potential solution to the paucity of novel antibiotics, either as natural inhibitors that can be used alone or in formulations with synergistically acting antibiotics. Here, we evaluate the potential of the antimicrobial peptide nisin to increase the efficacy of the antibiotics polymyxin and colistin, with a particular focus on their application to prevent biofilm formation of Pseudomonas aeruginosa. The results reveal that the concentrations of polymyxins that are required to effectively inhibit biofilm formation can be dramatically reduced when combined with nisin, thereby enhancing efficacy, and ultimately, restoring sensitivity. Such combination therapy may yield added benefits by virtue of reducing polymyxin toxicity through the administration of significantly lower levels of polymyxin antibiotics.
    • Variation in the quality of meat from Irish steers at the time of slaughter.

      Moloney, Aidan P; Mullen, Anne Maria; Maher, S.C.; Buckley, D.J.; Kerry, J.P. (Teagasc, 2004-01-01)
      There is no information on the variation in quality, in particular tenderness, that exists in Irish Beef nor is there information on the variation that would remain if optimum practices were imposed at all stages of the beef production chain. Evaluation of the success of measures to improve beef consistency requires information on existing variation and the minimum variation achievable.The objectives of this project were (i) to establish the variation that exists in the quality of meat from Irish cattle, (ii) to quantify the minimum variation in meat quality that can be achieved in a practical beef production system, (iii) to determine the effects and mechanisms of additional sources of variation. The conclusions from this project are: • The M. longissimus dorsi (loin) was found to be more variable than the M. semimembranosus (topside) for most quality attributes examined (tenderness, sarcomere length and pH). The scale of variation within the loin was similar to that reported by the other research groups within the EU and US. Heifers were more variable than steers for most attributes, while there was no consistent classification effect on the variability of meat quality attributes. • Tenderness was equally variable in meat from genetically similar steers, managed similarly, compared to commercial steers randomly selected from a factory lairage but matched for weight and grade.This was likely a result of both groups being crossbred beef cattle of similar age, fat score, carcass weight and managed identically post-mortem. However, variation in tenderness of both groups was less than that observed in a survey of commercial throughput (experiment 1). This decrease is attributed to better pre-and-post-slaughter handling practices. • The data suggest that selection of sires (within a breed) with better than average conformation has no deleterious effect on the eating quality of beef of their progeny.A more comprehensive comparison of sires within a breed and between breeds is required to confirm the generality of this conclusion. • In a comparison of genotypes, gender and slaughter weights, there was no evidence that variation around the mean value for tenderness differed between breeds or liveweights after 14 days ageing. Bulls were more variable than steers for some quality traits but the variation in tenderness was similar for bulls and steers after 14 days ageing. • While optimising the management of animals during the pre and post-slaughter period reduced variation in tenderness, some residual variation remained. A large percentage of the residual variation in tenderness (Warner Bratzler shear force) after 2 and 7 days post-mortem was explained by proteolysis (breakdown of myofibrillar proteins).Variation in tenderness (Warner Bratzler shear force) after 2 days post-mortem was largely explained by phosphates (energy) and proteolysis, while sensory tenderness was largely explained by phosphates and glycolytic potential. • Further work is required to reduce residual variation in Irish beef and to determine the causes of this variation.
    • Future Protein Supply and Demand: Strategies and Factors Influencing a Sustainable Equilibrium

      Henchion, Maeve; Hayes, Maria; Mullen, Anne Maria; Fenelon, Mark A.; Tiwari, Brijesh (MDPI, 2017-07-20)
      A growing global population, combined with factors such as changing socio-demographics, will place increased pressure on the world’s resources to provide not only more but also different types of food. Increased demand for animal-based protein in particular is expected to have a negative environmental impact, generating greenhouse gas emissions, requiring more water and more land. Addressing this “perfect storm” will necessitate more sustainable production of existing sources of protein as well as alternative sources for direct human consumption. This paper outlines some potential demand scenarios and provides an overview of selected existing and novel protein sources in terms of their potential to sustainably deliver protein for the future, considering drivers and challenges relating to nutritional, environmental, and technological and market/consumer domains. It concludes that different factors influence the potential of existing and novel sources. Existing protein sources are primarily hindered by their negative environmental impacts with some concerns around health. However, they offer social and economic benefits, and have a high level of consumer acceptance. Furthermore, recent research emphasizes the role of livestock as part of the solution to greenhouse gas emissions, and indicates that animal-based protein has an important role as part of a sustainable diet and as a contributor to food security. Novel proteins require the development of new value chains, and attention to issues such as production costs, food safety, scalability and consumer acceptance. Furthermore, positive environmental impacts cannot be assumed with novel protein sources and care must be taken to ensure that comparisons between novel and existing protein sources are valid. Greater alignment of political forces, and the involvement of wider stakeholders in a governance role, as well as development/commercialization role, is required to address both sources of protein and ensure food security