• 16S rRNA gene sequencing of mock microbial populations- impact of DNA extraction method, primer choice and sequencing platform

      Fouhy, Fiona; Clooney, Adam G; STANTON, CATHERINE; Claesson, Marcus J.; Cotter, Paul D.; European Union; Science Foundation Ireland; 603038; SFI/12/RC/2273; SFI/11/PI/1137 (Biomed Central, 24/06/2016)
      Background Next-generation sequencing platforms have revolutionised our ability to investigate the microbiota composition of complex environments, frequently through 16S rRNA gene sequencing of the bacterial component of the community. Numerous factors, including DNA extraction method, primer sequences and sequencing platform employed, can affect the accuracy of the results achieved. The aim of this study was to determine the impact of these three factors on 16S rRNA gene sequencing results, using mock communities and mock community DNA. Results The use of different primer sequences (V4-V5, V1-V2 and V1-V2 degenerate primers) resulted in differences in the genera and species detected. The V4-V5 primers gave the most comparable results across platforms. The three Ion PGM primer sets detected more of the 20 mock community species than the equivalent MiSeq primer sets. Data generated from DNA extracted using the 2 extraction methods were very similar. Conclusions Microbiota compositional data differed depending on the primers and sequencing platform that were used. The results demonstrate the risks in comparing data generated using different sequencing approaches and highlight the merits of choosing a standardised approach for sequencing in situations where a comparison across multiple sequencing runs is required.
    • 48 Altered gut microbiota in stable patients with cystic fibrosis (CF) compared to controls and its relationship with intravenous (IV) antibiotic usage and lung function

      Burke, D.G.; Fouhy, Fiona; Rea, Mary; Harrison, M.J.; STANTON, CATHERINE; O’Sullivan, Orla; Murphy, D. M.; O'Callaghan, G. P.; Eustace, J. A.; Shanahan, F.; et al. (Elsevier, 2015-06-05)
      Objective CF is associated with altered digestive function and thus nutrient availability for gut microbes in addition to altered gut microbiota, compared with healthy controls. Equally intensive antibiotic and nutritional therapy may further compound this. We present results from the largest CF gut microbiota study to date.
    • Actinomyces Produces Defensin-Like Bacteriocins (Actifensins) with a Highly Degenerate Structure and Broad Antimicrobial Activity

      Sugrue, Ivan; O’Connor, Paula M.; Hill, Colin; Stanton, Catherine; Ross, R. Paul; Teagasc Walsh Fellowship Programme; JPI; Science Foundation Ireland; SFI/12/RC/2273 (American Society for Microbiology, 2020-01-29)
      We identified a strain of Actinomyces ruminicola which produces a potent bacteriocin with activity against a broad range of Gram-positive bacteria, many of which are pathogenic to animals and humans. The bacteriocin was purified and found to have a mass of 4,091 ± 1 Da with a sequence of GFGCNLITSNPYQCSNHCKSVGYRGGYCKLRTVCTCY containing three disulfide bridges. Surprisingly, near relatives of actifensin were found to be a series of related eukaryotic defensins displaying greater than 50% identity to the bacteriocin. A pangenomic screen further revealed that production of actifensin-related bacteriocins is a common trait within the genus, with 47 being encoded in 161 genomes. Furthermore, these bacteriocins displayed a remarkable level of diversity with a mean amino acid identity of only 52% between strains/species. This level of redundancy suggests that this new class of bacteriocins may provide a very broad structural basis on which to deliver and design new broad-spectrum antimicrobials for treatment of animal and human infections. IMPORTANCE Bacteriocins (ribosomally produced antimicrobial peptides) are potential alternatives to current antimicrobials given the global challenge of antimicrobial resistance. We identified a novel bacteriocin from Actinomyces ruminicola with no previously characterized antimicrobial activity. Using publicly available genomic data, we found a highly conserved yet divergent family of previously unidentified homologous peptide sequences within the genus Actinomyces with striking similarity to eukaryotic defensins. These actifensins may provide a potent line of antimicrobial defense/offense, and the machinery to produce them could be used for the design of new antimicrobials given the degeneracy that exists naturally in their structure.
    • Adding value to milk by increasing its protein and CLA contents

      Murphy, J.J.; STANTON, CATHERINE; O'Donovan, Michael; Kavanagh, S.; Maher, J.; Patton, Joe; Mohammed, Riaz (Teagasc, 01/08/2008)
      The mid-summer milk protein study was undertaken on 34 commercial dairy farms in 2005 to evaluate the influence of dietary and management variables on milk protein content in mid-season. Data on grass composition, genetic merit of the herds and milk protein content were collected and analysed by multiple regression. Both calving date and genetic merit for milk protein content were significantly associated with milk protein content and were used as adjustment factors when evaluating the association between measures of grass quality and milk protein content. Milk protein content was associated with grass OMD (P = 0.04) and NDF content (P = 0.02) but not with CP content (P = 0.80). It is concluded that herds calving earlier, with a greater genetic merit for milk protein content and consuming better quality pasture would have greater milk protein contents in mid-season.
    • Administration of a live culture of Lactococcus lactis DPC 3147 into the bovine mammary gland stimulates the local host immune response, particularly IL-1β and IL-8 gene expression

      Beecher, Christine; Daly, Mairead; Berry, Donagh; Klostermann, Katja; Flynn, James; Meaney, William J; Hill, Colin; McCarthy, Tommie V; Ross, R Paul; Giblin, Linda; et al. (Cambridge University Press: Published for the Institute of Food Research and the Hannah Research Institute, 18/05/2009)
      Mastitis is one of the most costly diseases to the dairy farming industry. Conventional antibiotic therapy is often unsatisfactory for successful treatment of mastitis and alternative treatments are continually under investigation. We have previously demonstrated, in two separate field trials, that a probiotic culture, Lactococcus lactis DPC 3147, was comparable to antibiotic therapy to treat bovine mastitis. To understand the mode of action of this therapeutic, we looked at the detailed immune response of the host to delivery of this live strain directly into the mammary gland of six healthy dairy cows. All animals elicited signs of udder inflammation 7 h post infusion. At this time, clots were visible in the milk of all animals in the investigation. The most pronounced increase in immune gene expression was observed in Interleukin (IL)-1b and IL-8, with highest expression corresponding to peaks in somatic cell count. Infusion with a live culture of a Lc. lactis leads to a rapid and considerable innate immune response.
    • Algal Proteins: Extraction, Application, and Challenges Concerning Production

      Bleakley, Stephen; Hayes, Maria; Teagasc Walsh Fellowship Programme (MDPI, 26/04/2017)
      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
    • The altered gut microbiota in adults with cystic fibrosis

      Burke, D.G.; Fouhy, Fiona; Harrison, M. J; Rea, Mary; Cotter, Paul D.; O'Sullivan, Orla; STANTON, CATHERINE; Hill, Cian J; Shanahan, Fergus; Plant, Barry J.; et al. (Biomed Central, 09/03/2017)
      Background Cystic Fibrosis (CF) is an autosomal recessive disease that affects the function of a number of organs, principally the lungs, but also the gastrointestinal tract. The manifestations of cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction in the gastrointestinal tract, as well as frequent antibiotic exposure, undoubtedly disrupts the gut microbiota. To analyse the effects of CF and its management on the microbiome, we compared the gut microbiota of 43 individuals with CF during a period of stability, to that of 69 non-CF controls using 454-pyrosequencing of the 16S rRNA gene. The impact of clinical parameters, including antibiotic therapy, on the results was also assessed. Results The CF-associated microbiome had reduced microbial diversity, an increase in Firmicutes and a reduction in Bacteroidetes compared to the non-CF controls. While the greatest number of differences in taxonomic abundances of the intestinal microbiota was observed between individuals with CF and the healthy controls, gut microbiota differences were also reported between people with CF when grouped by clinical parameters including % predicted FEV1 (measure of lung dysfunction) and the number of intravenous (IV) antibiotic courses in the previous 12 months. Notably, CF individuals presenting with severe lung dysfunction (% predicted FEV1 ≤ 40%) had significantly (p < 0.05) reduced gut microbiota diversity relative to those presenting with mild or moderate dysfunction. A significant negative correlation (−0.383, Simpson’s Diversity Index) was also observed between the number of IV antibiotic courses and gut microbiota diversity. Conclusions This is one of the largest single-centre studies on gut microbiota in stable adults with CF and demonstrates the significantly altered gut microbiota, including reduced microbial diversity seen in CF patients compared to healthy controls. The data show the impact that CF and it's management have on gut microbiota, presenting the opportunity to develop CF specific probiotics to minimise microbiota alterations.
    • The altered gut microbiota in adults with cystic fibrosis

      Burke, D.G.; Fouhy, Fiona; Harrison, M. J; Rea, Mary; Cotter, Paul D.; O'Sullivan, Orla; STANTON, CATHERINE; Hill, Cian J; Shanahan, Fergus; Plant, Barry J.; et al. (Biomed Central, 09/03/2017)
      Background Cystic Fibrosis (CF) is an autosomal recessive disease that affects the function of a number of organs, principally the lungs, but also the gastrointestinal tract. The manifestations of cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction in the gastrointestinal tract, as well as frequent antibiotic exposure, undoubtedly disrupts the gut microbiota. To analyse the effects of CF and its management on the microbiome, we compared the gut microbiota of 43 individuals with CF during a period of stability, to that of 69 non-CF controls using 454-pyrosequencing of the 16S rRNA gene. The impact of clinical parameters, including antibiotic therapy, on the results was also assessed. Results The CF-associated microbiome had reduced microbial diversity, an increase in Firmicutes and a reduction in Bacteroidetes compared to the non-CF controls. While the greatest number of differences in taxonomic abundances of the intestinal microbiota was observed between individuals with CF and the healthy controls, gut microbiota differences were also reported between people with CF when grouped by clinical parameters including % predicted FEV1 (measure of lung dysfunction) and the number of intravenous (IV) antibiotic courses in the previous 12 months. Notably, CF individuals presenting with severe lung dysfunction (% predicted FEV1 ≤ 40%) had significantly (p < 0.05) reduced gut microbiota diversity relative to those presenting with mild or moderate dysfunction. A significant negative correlation (−0.383, Simpson’s Diversity Index) was also observed between the number of IV antibiotic courses and gut microbiota diversity. Conclusions This is one of the largest single-centre studies on gut microbiota in stable adults with CF and demonstrates the significantly altered gut microbiota, including reduced microbial diversity seen in CF patients compared to healthy controls. The data show the impact that CF and it's management have on gut microbiota, presenting the opportunity to develop CF specific probiotics to minimise microbiota alterations.
    • Analysis of Health Benefits Conferred by Lactobacillus Species from Kefir

      Cotter, Paul D.; Slattery, Conor; O'Toole, Paul W.; Department of Agriculture, Food and Marine; Science Foundation Ireland; APC Microbiome Ireland; Vistamilk; Enterprise Ireland; European Union; 818368 (MDPI, 2019-06-01)
      Lactobacilli are among the most common microorganisms found in kefir; a traditional fermented milk beverage produced locally in many locations around the world. Kefir has been associated with a wide range of purported health benefits; such as antimicrobial activity; cholesterol metabolism; immunomodulation; anti-oxidative effects; anti-diabetic effects; anti-allergenic effects; and tumor suppression. This review critically examines and assesses these claimed benefits and mechanisms with regard to particular Lactobacillus species and/or strains that have been derived from kefir; as well as detailing further potential avenues for experimentation.
    • Antibiotic Resistance in the Gut Microbiota

      Fouhy, Fiona; Teagasc Walsh Fellowship Programme; Irish Research Council (2014)
      Antibiotic resistance is an increasing threat to our ability to treat infectious diseases. Thus, understanding the effects of antibiotics on the gut microbiota, as well as the potential for such populations to act as a reservoir for resistance genes, is imperative. This thesis set out to investigate the gut microbiota of antibiotic treated infants compared to untreated controls using high-throughput DNA sequencing. The results demonstrated the significant effects of antibiotic treatment, resulting in increased proportions of Proteobacteria and decreased proportions of Bifidobacterium. The species diversity of bifidobacteria was also reduced. This thesis also highlights the ability of the human gut microbiota to act as an antibiotic resistance reservoir. Using metagenomic DNA extracted from faecal samples from adult males, PCR was employed to demonstrate the prevalence and diversity of aminoglycoside and β-lactam resistance genes in the adult gut microbiota and highlighted the merits of the approach adopted. Using infant faecal samples, we constructed and screened a second fosmid metagenomic bank for the same families of resistance genes and demonstrated that the infant gut microbiota is also a reservoir for resistance genes. Using in silico analysis we highlighted the existence of putative aminoglycoside and β-lactam resistance determinants within the genomes of Bifidobacterium species. In the case of the β- lactamases, these appear to be mis-annotated. However, through homologous recombination-mediated insertional inactivation, we have demonstrated that the putative aminoglycoside resistance proteins do contribute to resistance. In additional studies, we investigated the effects of short bowel syndrome on infant gut microbiota, the immune system and bile acid metabolism. We also sequenced the microbiota of the human vermiform appendix, highlighting its complexity. Finally, this thesis demonstrated the strain specific nature of 2 different probiotic CLA-producing Bifidobacterium breve on the murine gut microbiota.
    • Antifungal Peptides as Therapeutic Agents

      Fernández de Ullivarri, Miguel; Arbulu, Sara; Garcia-Gutierrez, Enriqueta; Cotter, Paul D.; Science Foundation Ireland; European Union; Teagasc Walsh Fellowship Programme; SFI/12/RC/2273; 754535; 2015066 (Frontiers Media SA, 2020-03-17)
      Fungi have been used since ancient times in food and beverage-making processes and, more recently, have been harnessed for the production of antibiotics and in processes of relevance to the bioeconomy. Moreover, they are starting to gain attention as a key component of the human microbiome. However, fungi are also responsible for human infections. The incidence of community-acquired and nosocomial fungal infections has increased considerably in recent decades. Antibiotic resistance development, the increasing number of immunodeficiency- and/or immunosuppression-related diseases and limited therapeutic options available are triggering the search for novel alternatives. These new antifungals should be less toxic for the host, with targeted or broader antimicrobial spectra (for diseases of known and unknown etiology, respectively) and modes of actions that limit the potential for the emergence of resistance among pathogenic fungi. Given these criteria, antimicrobial peptides with antifungal properties, i.e., antifungal peptides (AFPs), have emerged as powerful candidates due to their efficacy and high selectivity. In this review, we provide an overview of the bioactivity and classification of AFPs (natural and synthetic) as well as their mode of action and advantages over current antifungal drugs. Additionally, natural, heterologous and synthetic production of AFPs with a view to greater levels of exploitation is discussed. Finally, we evaluate the current and potential applications of these peptides, along with the future challenges relating to antifungal treatments.
    • Antimicrobial antagonists against food pathogens; a bacteriocin perspective

      O'Connor, Paula M.; Ross, R Paul; Hill, Colin; Cotter, Paul D.; Science Foundation Ireland; 12/RC/2273 (Elsevier, 03/02/2015)
      Efforts are continuing to find novel bacteriocins with enhanced specificity and potency. Traditional plating techniques are still being used for bacteriocin screening studies, however, the availability of ever more bacterial genome sequences and the use of in silico gene mining tools have revealed novel bacteriocin gene clusters that would otherwise have been overlooked. Furthermore, synthetic biology and bioengineering-based approaches are allowing scientists to harness existing and novel bacteriocin gene clusters through expression in different hosts and by enhancing functionalities. The same principles apply to bacteriocin producing probiotic cultures and their application to control pathogens in the gut. We can expect that the recent developments on bacteriocins from Lactic Acid Bacteria (LAB) described here will contribute greatly to increased commercialisation of bacteriocins in food systems.
    • Antimicrobials for food and feed; a bacteriocin perspective

      O'Connor, Paula M.; Kuniyoshi, Tais M.; Oliveira, Ricardo PS; Hill, Colin; Ross, R Paul; Cotter, Paul D.; Science Foundation Ireland; São Paulo Research Foundation; 12/RC/2273; 2015/24777-0; et al. (Elsevier, 2020-01-20)
      Bacteriocins are natural antimicrobials that have been consumed via fermented foods for millennia and have been the focus of renewed efforts to identify novel bacteriocins, and their producing microorganisms, for use as food biopreservatives and other applications. Bioengineering bacteriocins or combining bacteriocins with multiple modes of action (hurdle approach) can enhance their preservative effect and reduces the incidence of antimicrobial resistance. In addition to their role as food biopreservatives, bacteriocins are gaining credibility as health modulators, due to their ability to regulate the gut microbiota, which is strongly associated with human wellbeing. Indeed the strengthening link between the gut microbiota and obesity make bacteriocins ideal alternatives to Animal Growth Promoters (AGP) in animal feed also. Here we review recent advances in bacteriocin research that will contribute to the development of functional foods and feeds as a consequence of roles in food biopreservation and human/animal health.
    • Antioxidant Activity and Phytochemical Characterization of Senecio clivicolus Wedd.

      Faraone, Immacolata; Rai, Dilip K.; Chiummiento, Lucia; Fernandez, Eloy; Choudhary, Alka; Prinzo, Flavio; Milella, Luigi; University of Basilicata; D.G.R. 1490 (MDPI, 2018-09-29)
      Antioxidant phytochemicals play a key role in oxidative stress control and in the prevention of related disorders, such as premature aging, degenerative diseases, diabetes, and cancer. The aim of this study was to investigate the potential antioxidant activity and the phytochemical profile of Senecio clivicolus Wedd., a perennial shrub, belonging to the Asteraceae family. Despite the wide interest of this family, this specie has not been investigated yet. S. clivicolus aerial parts were extracted with 96% ethanol. Then, the ethanol extract was fractionated by liquid/liquid extraction using an increasing solvents polarity. Total polyphenol and terpenoid contents were measured. Moreover, the antioxidant activity was evaluated by six different complementary in vitro assays. The Relative Antioxidant Capacity Index (RACI) was used to compare data obtained by different tests. The sample showing the highest RACI was subjected to characterization and quantitation of its phenolic composition using LC-MS/MS analysis. The ethyl acetate fraction, investigated by LC-MS/MS analysis, showed 30 compounds, most of them are chlorogenic acid and flavonoid derivatives. To the best of our knowledge, this is the first report about the evaluation of antioxidant activity and phytochemical profile of S. clivicolus, underlying the importance of this species as a source of health-promoting phytochemicals.
    • Antioxidant Activity and Phytochemical Characterization of Senecio clivicolus Wedd.

      Faraone, Immacolata; Rai, Dilip K.; Chiummiento, Lucia; Fernandez, Eloy; Choudhary, Alka; Prinzo, Flavio; Milella, Luigi; University of Basilicata; D.G.R. 1490 (MDPI, 2018-09-29)
      Antioxidant phytochemicals play a key role in oxidative stress control and in the prevention of related disorders, such as premature aging, degenerative diseases, diabetes, and cancer. The aim of this study was to investigate the potential antioxidant activity and the phytochemical profile of Senecio clivicolus Wedd., a perennial shrub, belonging to the Asteraceae family. Despite the wide interest of this family, this specie has not been investigated yet. S. clivicolus aerial parts were extracted with 96% ethanol. Then, the ethanol extract was fractionated by liquid/liquid extraction using an increasing solvents polarity. Total polyphenol and terpenoid contents were measured. Moreover, the antioxidant activity was evaluated by six different complementary in vitro assays. The Relative Antioxidant Capacity Index (RACI) was used to compare data obtained by different tests. The sample showing the highest RACI was subjected to characterization and quantitation of its phenolic composition using LC-MS/MS analysis. The ethyl acetate fraction, investigated by LC-MS/MS analysis, showed 30 compounds, most of them are chlorogenic acid and flavonoid derivatives. To the best of our knowledge, this is the first report about the evaluation of antioxidant activity and phytochemical profile of S. clivicolus, underlying the importance of this species as a source of health-promoting phytochemicals
    • Antioxidant, Antidiabetic, and Anticholinesterase Activities and Phytochemical Profile of Wedd.

      Faraone, Immacolata; Rai, Dilip K.; Russo, Daniela; Chiummiento, Lucia; Fernandez, Eloy; Choudhary, Alka; Milella, Luigi; Regione Basilicata; Fondazione Enrico Mattei DGR; Regional Project ALIMINTEGRA, GO NUTRIBAS; et al. (MDPI, 2019-08-03)
      Oxidative stress is involved in different diseases, such as diabetes and neurodegenerative diseases. The genus Azorella includes about 70 species of flowering plant species; most of them are commonly used as food and in particular as a tea infusion in the Andean region of South America in folk medicine to treat various chronic diseases. Azorella glabra Wedd. aerial parts were firstly analyzed for their in vitro antioxidant activity using different complementary assays. In particular, radical scavenging activity was tested against biological neutral radical DPPH; ferric reducing power and lipid peroxidation inhibitory capacity (FRAP and Beta-Carotene Bleaching tests) were also determined. The Relative Antioxidant Capacity Index (RACI) was used to compare data obtained by different assays. Then, the inhibitory ability of samples was investigated against α-amylase and α-glucosidase enzymes involved in diabetes and against acetylcholinesterase and butyrylcholinesterase enzymes considered as strategy for the treatment of Parkinson's or Alzheimer's diseases. Moreover, the phytochemical profile of the sample showing the highest RACI (1.35) and interesting enzymatic activities (IC50 of 163.54 ± 9.72 and 215.29 ± 17.10 μg/mL in α-glucosidase and acetylcholinesterase inhibition, respectively) was subjected to characterization and quantification of its phenolic composition using LC-MS/MS analysis. In fact, the ethyl acetate fraction derived from ethanol extract by liquid/liquid extraction showed 29 compounds, most of them are cinnamic acid derivatives, flavonoid derivatives, and a terpene. To the best of our knowledge, this is the first report about the evaluation of significant biological activities and phytochemical profile of A. glabra, an important source of health-promoting phytochemicals.
    • Antioxidant, Antidiabetic, and Anticholinesterase Activities and Phytochemical Profile of Azorella glabra Wedd

      Faraone, Immacolata; Rai, Dilip K.; Russo, Daniela; Chiummiento, Lucia; Fernandez, Eloy; Choudhary, Alka; Milella, Luigi; Regione Basilicata; Fondazione Enrico Mattei DGR; ALIMINTEGRA, GO NUTRIBAS; et al. (MDPI, 2019-08-03)
      Oxidative stress is involved in different diseases, such as diabetes and neurodegenerative diseases. The genus Azorella includes about 70 species of flowering plant species; most of them are commonly used as food and in particular as a tea infusion in the Andean region of South America in folk medicine to treat various chronic diseases. Azorella glabra Wedd. aerial parts were firstly analyzed for their in vitro antioxidant activity using different complementary assays. In particular, radical scavenging activity was tested against biological neutral radical DPPH; ferric reducing power and lipid peroxidation inhibitory capacity (FRAP and Beta-Carotene Bleaching tests) were also determined. The Relative Antioxidant Capacity Index (RACI) was used to compare data obtained by different assays. Then, the inhibitory ability of samples was investigated against α-amylase and α-glucosidase enzymes involved in diabetes and against acetylcholinesterase and butyrylcholinesterase enzymes considered as strategy for the treatment of Parkinson’s or Alzheimer’s diseases. Moreover, the phytochemical profile of the sample showing the highest RACI (1.35) and interesting enzymatic activities (IC50 of 163.54 ± 9.72 and 215.29 ± 17.10 μg/mL in α-glucosidase and acetylcholinesterase inhibition, respectively) was subjected to characterization and quantification of its phenolic composition using LC-MS/MS analysis. In fact, the ethyl acetate fraction derived from ethanol extract by liquid/liquid extraction showed 29 compounds, most of them are cinnamic acid derivatives, flavonoid derivatives, and a terpene. To the best of our knowledge, this is the first report about the evaluation of significant biological activities and phytochemical profile of A. glabra, an important source of health-promoting phytochemicals.
    • Aquaculture Production of the Brown Seaweeds Laminaria digitata and Macrocystis pyrifera: Applications in Food and Pharmaceuticals

      Purcell-Meyerink, Diane; Packer, Michael A.; Wheeler, Thomas T.; Hayes, Maria; Teagasc; European Union; 754380 (Multidisciplinary Digital Publishing Institute, 2021-02-28)
      Seaweeds have a long history of use as food, as flavouring agents, and find use in traditional folk medicine. Seaweed products range from food, feed, and dietary supplements to pharmaceuticals, and from bioenergy intermediates to materials. At present, 98% of the seaweed required by the seaweed industry is provided by five genera and only ten species. The two brown kelp seaweeds Laminaria digitata, a native Irish species, and Macrocystis pyrifera, a native New Zealand species, are not included in these eleven species, although they have been used as dietary supplements and as animal and fish feed. The properties associated with the polysaccharides and proteins from these two species have resulted in increased interest in them, enabling their use as functional foods. Improvements and optimisations in aquaculture methods and bioproduct extractions are essential to realise the commercial potential of these seaweeds. Recent advances in optimising these processes are outlined in this review, as well as potential future applications of L. digitata and, to a greater extent, M. pyrifera which, to date, has been predominately only wild-harvested. These include bio-refinery processing to produce ingredients for nutricosmetics, functional foods, cosmeceuticals, and bioplastics. Areas that currently limit the commercial potential of these two species are highlighted
    • Aroma compound diacetyl suppresses glucagon-like peptide-1 production and secretion in STC-1 cells

      McCarthy, Triona; Bruen, Christine; O'Halloran, Fiona; Schellekens, Harriet; Kilcawley, Kieran; Cryan, John F.; Giblin, Linda; Teagasc Walsh Fellowship Programme; Enterprise Ireland; CC20080001 (Elsevier, 21/01/2017)
      Diacetyl is a volatile flavour compound that has a characteristic buttery aroma and is widely used in the flavour industry. The aroma of a food plays an important role in food palatability and thus intake. This study investigates the effect of diacetyl on the satiety hormone, glucagon-like peptide (GLP-1), using the enteroendocrine cell line, STC-1. Diacetyl decreased proglucagon mRNA and total GLP-1 from glucose stimulated STC-1 cells. This dampening effect on GLP-1 appears to be mediated by increasing intracellular cAMP levels, increasing synthesis of the G protein coupled receptor, GPR120, and its recruitment to the cell surface. Voltage gated Ca2+ channels, K+ATP channels and the α-gustducin taste pathway do not appear to be involved. These findings demonstrate that components contributing to food palatability suppress GLP-1. This ability of diacetyl to reduce satiety signals may contribute to overconsumption of some palatable foods.
    • Assessing the ability of Nisin A and derivatives thereof to inhibit Gram-negative bacteria from the genus Thermus

      Jonnala, Bhagya R. Yeluri; Feehily, Conor; O'Connor, Paula M.; Field, Des; Hill, Colin; Ross, R. Paul; McSweeney, P. L. H.; Sheehan, Diarmuid (JJ); Cotter, Paul D. (2020-12-09)