Now showing items 21-40 of 3555

    • Forgotten fungi—the gut mycobiome in human health and disease

      Huseyin, Chloe E.; O’Toole, Paul W.; Cotter, Paul D.; Scanlan, Pauline D.; Science Foundation Ireland (SFI); Science Foundation Ireland-Royal Society University Research Fellowship; SFI/12/RC/2273 (Oxford University Press (OUP), 2017-04-18)
      The human body is home to a complex and diverse microbial ecosystem that plays a central role in host health. This includes a diversity of fungal species that is collectively referred to as our ‘mycobiome’. Although research into the mycobiome is still in its infancy, its potential role in human disease is increasingly recognised. Here we review the existing literature available on the human mycobiota with an emphasis on the gut mycobiome, including how fungi interact with the human host and other microbes. In doing so, we provide a comprehensive critique of the methodologies available to research the human mycobiota as well as highlighting the latest research findings from mycological surveys of different groups of interest including infants, obese and inflammatory bowel disease cohorts. This in turn provides new insights and directions for future studies in this burgeoning research area.
    • Farm-level viability, sustainability and resilience: a focus on cooperative action and values-based supply chains

      Hooks, Teresa; Macken-Walsh, Áine; McCarthy, Olive; Power, Carol; Teagasc’s Walsh Fellowship Scheme (NAIK Research Institute of Agricultural Economics, 2017-12-01)
      This paper presents a critical discussion of the concepts of farm-level viability, sustainability and resilience, which are typically discussed separately in the literature. While farm-level viability frequently focuses on measurable economic factors, sustainability is comparatively more elusive because of its added social, cultural and ecological dimensions. Resilience, in turn, is unambiguous in the sense that it requires particular conditions, but is achieved in dynamic ways. A traditional resilience strategy in agriculture globally is co-operative action, involving farmers working together to enhance their viability and sustainability, often achieving resilience. We draw attention to agricultural development models that are distinctive because they leverage co-operative action in and between family farms in agricultural communities while pursuing integrated viability, sustainability and resilience strategies. We focus on the prospect of such rural development models, particularly a values-based supply chain approach, and identify crucial considerations and future research needs.
    • Enhancing the diversity of breeding invertebrates within field margins of intensively managed grassland: Effects of alternative management practices

      Fritch, Rochelle A.; Sheridan, Helen; Finn, John A.; McCormack, Stephen; Ó hUallacháin, Daire; Department of Agriculture, Food and the Marine; RSF 06 382 (Wiley, 2017-10-19)
      Severe declines in biodiversity have been well documented for many taxonomic groups due to intensification of agricultural practices. Establishment and appropriate management of arable field margins can improve the diversity and abundance of invertebrate groups; however, there is much less research on field margins within grassland systems. Three grassland field margin treatments (fencing off the existing vegetation “fenced”; fencing with rotavation and natural regeneration “rotavated” and; fencing with rotavation and seeding “seeded”) were compared to a grazed control in the adjacent intensively managed pasture. Invertebrates were sampled using emergence traps to investigate species breeding and overwintering within the margins. Using a manipulation experiment, we tested whether the removal of grazing pressure and nutrient inputs would increase the abundance and richness of breeding invertebrates within grassland field margins. We also tested whether field margin establishment treatments, with their different vegetation communities, would change the abundance and richness of breeding invertebrates in the field margins. Exclusion of grazing and nutrient inputs led to increased abundance and richness in nearly all invertebrate groups that we sampled. However, there were more complex effects of field margin establishment treatment on the abundance and richness of invertebrate taxa. Each of the three establishment treatments supported a distinct invertebrate community. The removal of grazing from grassland field margins provided a greater range of overwintering/ breeding habitat for invertebrates. We demonstrate the capacity of field margin establishment to increase the abundance and richness in nearly all invertebrate groups in study plots that were located on previously more depauperate areas of intensively managed grassland. These results from grassland field margins provide evidence to support practical actions that can inform Greening (Pillar 1) and agri-environment measures (Pillar 2) of the Common Agricultural Policy (CAP). Before implementing specific management regimes, the conservation aims of agri-environment measures should be clarified by defining the target species or taxonomic groups.
    • Characterisation of the Wetting Behaviour of Poor Wetting Food Powders and the Influence of Temperature and Film Formation

      Fitzpatrick, John J.; Salmon, Justine; Ji, Junfu; Miao, Song (Hosokawa Powder Technology Foundation, 2017)
      Characterisation of the wettability of five poor wetting food powders was performed using static immersion and contact angle measurements. The effect of temperature (20, 50 and 70 °C) on wettability showed varying effects on the powders. Higher temperatures majorly improved the wettability of chocolate and high fat powders but worsened the wettability of sodium caseinate and milk protein isolate. Rate-limiting regime testing was performed by pouring a fixed mass of powder on to the surface of water in an agitated beaker and visually assessing what was rate-limiting rehydration after 1 minute. The rate limiting regime tended to be floating at lower agitation speeds and dispersed clumps of varying sizes at higher speeds. However, there were major differences observed between the powders. Some of the powders formed strong films at powder/water interfaces, that could act as a barrier to water penetration and wettability. Consequently, force displacement testing was performed on a layer of powder on the water surface to assess the strength of any powder film formed. Some of the powders formed strong films that may in-part explain their poor wetting behaviour and their propensity to form strong clumps that were difficult to disrupt.
    • The creation and evaluation of a model to simulate the probability of conception in seasonal-calving pasture-based dairy heifers

      Fenlon, Caroline; O’Grady, Luke; Butler, Stephen; Doherty, Michael L.; Dunnion, John; Dairy Research Ireland (Springer Science and Business Media LLC, 2017-11-22)
      Background: Herd fertility in pasture-based dairy farms is a key driver of farm economics. Models for predicting nulliparous reproductive outcomes are rare, but age, genetics, weight, and BCS have been identified as factors influencing heifer conception. The aim of this study was to create a simulation model of heifer conception to service with thorough evaluation. Methods: Artificial Insemination service records from two research herds and ten commercial herds were provided to build and evaluate the models. All were managed as spring-calving pasture-based systems. The factors studied were related to age, genetics, and time of service. The data were split into training and testing sets and bootstrapping was used to train the models. Logistic regression (with and without random effects) and generalised additive modelling were selected as the model-building techniques. Two types of evaluation were used to test the predictive ability of the models: discrimination and calibration. Discrimination, which includes sensitivity, specificity, accuracy and ROC analysis, measures a model’s ability to distinguish between positive and negative outcomes. Calibration measures the accuracy of the predicted probabilities with the Hosmer-Lemeshow goodness-of-fit, calibration plot and calibration error. Results: After data cleaning and the removal of services with missing values, 1396 services remained to train the models and 597 were left for testing. Age, breed, genetic predicted transmitting ability for calving interval, month and year were significant in the multivariate models. The regression models also included an interaction between age and month. Year within herd was a random effect in the mixed regression model. Overall prediction accuracy was between 77.1% and 78.9%. All three models had very high sensitivity, but low specificity. The two regression models were very well-calibrated. The mean absolute calibration errors were all below 4%. Conclusion: Because the models were not adept at identifying unsuccessful services, they are not suggested for use in predicting the outcome of individual heifer services. Instead, they are useful for the comparison of services with different covariate values or as sub-models in whole-farm simulations. The mixed regression model was identified as the best model for prediction, as the random effects can be ignored and the other variables can be easily obtained or simulated.
    • Glycomacropeptide Reduces Intestinal Epithelial Cell Barrier Dysfunction and Adhesion of Entero-Hemorrhagic and Entero-Pathogenic Escherichia coli in Vitro

      Feeney, Shane; Ryan, Joseph; Kilcoyne, Michelle; Joshi, Lokesh; Hickey, Rita; Teagasc Walsh Fellowship; Department of Agriculture and Food, Ireland; 10/RD/NUIG/707 (Multidisciplinary Digital Publishing Institute, 2017-10-27)
      In recent years, the potential of glycosylated food components to positively influence health has received considerable attention. Milk is a rich source of biologically active glycoconjugates which are associated with antimicrobial, immunomodulatory, anti-adhesion, anti-inflammatory and prebiotic properties. Glycomacropeptide (GMP) is the C-terminal portion of kappa-casein that is released from whey during cheese-making by the action of chymosin. Many of the biological properties associated with GMP, such as anti-adhesion, have been linked with the carbohydrate portion of the protein. In this study, we investigated the ability of GMP to inhibit the adhesion of a variety of pathogenic Escherichia coli strains to HT-29 and Caco-2 intestinal cell lines, given the importance of E. coli in causing bacterial gastroenteritis. GMP significantly reduced pathogen adhesion, albeit with a high degree of species specificity toward enteropathogenic E. coli (EPEC) strains O125:H32 and O111:H2 and enterohemorrhagic E. coli (EHEC) strain 12900 O157:H7. The anti-adhesive effect resulted from the interaction of GMP with the E. coli cells and was also dependent on GMP concentration. Pre-incubation of intestinal Caco-2 cells with GMP reduced pathogen translocation as represented by a decrease in transepithelial electrical resistance (TEER). Thus, GMP is an effective in-vitro inhibitor of adhesion and epithelial injury caused by E. coli and may have potential as a biofunctional ingredient in foods to improve gastrointestinal health.
    • Boarfish (Capros aper): review of a new capture fishery and its valorization potential

      Egerton, Sian; Culloty, Sarah; Whooley, Jason; STANTON, CATHERINE; Ross, R. Paul; Irish Research Council (IRC); Biomarine Ingredients Ireland Ltd. via the IRC Enterprise Partnership Scheme (Oxford University Press (OUP), 2017-04-18)
      The world’s fish stocks, although renewable, are a finite resource. European capture fisheries have remained stagnant in terms of volume for many years. To remain profitable, fishers are looking for new opportunities to diversify, reduce costs, and maximize profits. The targeted fishing of boarfish (Capros aper) in Europe is an excellent example of such adaptation. Using this fishery as a case study, we highlight how established fisheries are adapting to changes faced by the industry. We begin by compiling the knowledge to date on the taxonomy, biology, and ecology of the understudied boarfish and go on to provide a comprehensive overview of its expansion as a targeted fishery in Europe, examining the range of valorization options currently being investigated.
    • Metagenome-based surveillance and diagnostic approaches to studying the microbial ecology of food production and processing environments

      Doyle, Conor J.; O'Toole, Paul W.; Cotter, Paul D.; Teagasc Walsh Fellowship; internal Teagasc funding; 2013030; RMIS6364 (Wiley, 2017-09-14)
      Metagenomic-based analyses have the potential to revolutionize our understanding of the microbiology of food production and processing environments. By adopting such approaches, it will be possible to more accurately determine sources of microbial contamination, identify critical control points for such contaminants, and select practices that optimize quality and safety. This mini-review will discuss the merits of adopting metagenostic-based approaches, highlight novel insights that they have provided to date and consider how they could be further implemented.
    • Impacts of Seasonal Housing and Teat Preparation on Raw Milk Microbiota: a High-Throughput Sequencing Study

      Doyle, Conor J.; Gleeson, David; O'Toole, Paul W.; Cotter, Paul D.; Teagasc Walsh Fellowship; internal Teagasc funding; 2013030; RMIS6364 (American Society for Microbiology, 2017-01-15)
      In pasture-based systems, changes in dairy herd habitat due to seasonality results in the exposure of animals to different environmental niches. These niches contain distinct microbial communities that may be transferred to raw milk, with potentially important food quality and safety implications for milk producers. It is postulated that the extent to which these microorganisms are transferred could be limited by the inclusion of a teat preparation step prior to milking. High-throughput sequencing on a variety of microbial niches on farms was used to study the patterns of microbial movement through the dairy production chain and, in the process, to investigate the impact of seasonal housing and the inclusion/exclusion of a teat preparation regime on the raw milk microbiota from the same herd over two sampling periods, i.e., indoor and outdoor. Beta diversity and network analyses showed that environmental and milk microbiotas separated depending on whether they were sourced from an indoor or outdoor environment. Within these respective habitats, similarities between the milk microbiota and that of teat swab samples and, to a lesser extent, fecal samples were apparent. Indeed, SourceTracker identified the teat surface as the most significant source of contamination, with herd feces being the next most prevalent source of contamination. In milk from cows grazing outdoors, teat prep significantly increased the numbers of total bacteria present. In summary, sequence-based microbiota analysis identified possible sources of raw milk contamination and highlighted the influence of environment and farm management practices on the raw milk microbiota.
    • A review of water quality policies in relation to public good benefits and community engagement in rural Ireland

      Daly, Karen; Breuil, Marion; Buckley, Cathal; O’ Donoghue, Cathal; Ryan, Mary; Seale, Catherine (Sciendo, 2017-04-06)
      This paper examines current recreational water use in the rural landscape in Ireland and reviews current EU policies and national regulations aimed at protecting water quality and the wider environment under agri-environmental schemes. Specifically, we review policy instruments that protect water for recreational use, their impacts and the challenges they pose for rural development against current requirements to increase public awareness and participation. In Ireland, there is limited experience in public participation in water quality protection and restoration and we highlight how this can be addressed by focussing on the specific contribution of water quality in rural areas in relation to the provision of recreational ecosystem services. These services provide the infrastructure for much of Ireland’s rural tourism sector. In this context, emerging participatory approaches to policy implementation are also assessed as national and local government prioritise community engagement for the second cycle under the EU Water Framework Directive (WFD).
    • Economic Assessment of Waterborne Outbreak of Cryptosporidiosis

      Chyzheuskaya, Aksana; Cormican, Martin; Srivinas, Raghavendra; O’Donovan, Diarmuid; Prendergast, Martina; O’Donoghue, Cathal; Morris, Dearbháile (Centers for Disease Control and Prevention (CDC), 2017-10)
      In 2007, a waterborne outbreak of Cryptosporidium hominis infection occurred in western Ireland, resulting in 242 laboratory-confirmed cases and an uncertain number of unconfirmed cases. A boil water notice was in place for 158 days that affected 120,432 persons residing in the area, businesses, visitors, and commuters. This outbreak represented the largest outbreak of cryptosporidiosis in Ireland. The purpose of this study was to evaluate the cost of this outbreak. We adopted a societal perspective in estimating costs associated with the outbreak. Economic cost estimated was based on totaling direct and indirect costs incurred by public and private agencies. The cost of the outbreak was estimated based on 2007 figures. We estimate that the cost of the outbreak was >€19 million (≈€120,000/day of the outbreak). The US dollar equivalent based on today’s exchange rates would be $22.44 million (≈$142,000/day of the outbreak). This study highlights the economic need for a safe drinking water supply.
    • Preparation and Characterization of Nanoparticles Made from Co-Incubation of SOD and Glucose

      Cai, Liping; Lin, Chuntong; Yang, Nannan; Huang, Zhijie; Miao, Song; Chen, Xiaochao; Pan, Jianru; Rao, Pingfan; Liu, Shutao; National key research and development projects; et al. (Multidisciplinary Digital Publishing Institute, 2017-12-19)
      The attractive potential of natural superoxide dismutase (SOD) in the fields of medicine and functional food is limited by its short half-life in circulation and poor permeability across the cell membrane. The nanoparticle form of SOD might overcome these limitations. However, most preparative methods have disadvantages, such as complicated operation, a variety of reagents-some of them even highly toxic-and low encapsulation efficiency or low release rate. The aim of this study is to present a simple and green approach for the preparation of SOD nanoparticles (NPs) by means of co-incubation of Cu/Zn SOD with glucose. This method was designed to prepare nanoscale aggregates based on the possible inhibitory effect of Maillard reaction on heating-induced aggregation during the co-incubation. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) results indicated that the Maillard reaction occurred during the co-incubation process. It was found that enzymatically active NPs of Cu/Zn SOD were simultaneously generated during the reaction, with an average particle size of 175.86 ± 0.71 nm, and a Zeta potential of -17.27 ± 0.59 mV, as established by the measurement of enzymatic activity, observations using field emission scanning electron microscope, and analysis of dynamic light scattering, respectively. The preparative conditions for the SOD NPs were optimized by response surface design to increase SOD activity 20.43 fold. These SOD NPs showed storage stability for 25 days and better cell uptake efficacy than natural SOD. Therefore, these NPs of SOD are expected to be a potential drug candidate or functional food factor. To our knowledge, this is the first report on the preparation of nanoparticles possessing the bioactivity of the graft component protein, using the simple and green approach of co-incubation with glucose, which occurs frequently in the food industry during thermal processing.
    • Bacteriophages and Bacterial Plant Diseases

      Buttimer, Colin; McAuliffe, Olivia; Ross, R. P.; Hill, Colin; O’Mahony, Jim; Coffey, Aidan; CIT Rísam Ph.D. Scholarship (Frontiers Media SA, 2017-01-20)
      Losses in crop yields due to disease need to be reduced in order to meet increasing global food demands associated with growth in the human population. There is a well-recognized need to develop new environmentally friendly control strategies to combat bacterial crop disease. Current control measures involving the use of traditional chemicals or antibiotics are losing their efficacy due to the natural development of bacterial resistance to these agents. In addition, there is an increasing awareness that their use is environmentally unfriendly. Bacteriophages, the viruses of bacteria, have received increased research interest in recent years as a realistic environmentally friendly means of controlling bacterial diseases. Their use presents a viable control measure for a number of destructive bacterial crop diseases, with some phage-based products already becoming available on the market. Phage biocontrol possesses advantages over chemical controls in that tailor-made phage cocktails can be adapted to target specific disease-causing bacteria. Unlike chemical control measures, phage mixtures can be easily adapted for bacterial resistance which may develop over time. In this review, we will examine the progress and challenges for phage-based disease biocontrol in food crops.
    • Things Are Getting Hairy: Enterobacteria Bacteriophage vB_PcaM_CBB

      Buttimer, Colin; Hendrix, Hanne; Oliveira, Hugo; Casey, Aidan; Neve, Horst; McAuliffe, Olivia; Ross, R. Paul; Hill, Colin; Noben, Jean-Paul; O'Mahony, Jim; et al. (Frontiers Media SA, 2017-01-24)
      Enterobacteria phage vB_PcaM_CBB is a “jumbo” phage belonging to the family Myoviridae. It possesses highly atypical whisker-like structures along the length of its contractile tail. It has a broad host range with the capability of infecting species of the genera Erwinia, Pectobacterium, and Cronobacter. With a genome of 355,922 bp, excluding a predicted terminal repeat of 22,456 bp, phage CBB is the third largest phage sequenced to date. Its genome was predicted to encode 554 ORFs with 33 tRNAs. Based on prediction and proteome analysis of the virions, 29% of its predicted ORFs could be functionally assigned. Protein comparison shows that CBB shares between 33–38% of its proteins with Cronobacter phage GAP32, coliphages PBECO4 and 121Q as well as Klebsiella phage vB_KleM_Rak2. This work presents a detailed and comparative analysis of vB_PcaM_CBB of a highly atypical jumbo myoviridae phage, contributing to a better understanding of phage diversity and biology.
    • Predicted Release and Analysis of Novel ACE-I, Renin, and DPP-IV Inhibitory Peptides from Common Oat (Avena sativa) Protein Hydrolysates Using in Silico Analysis

      Bleakley, Stephen; Hayes, Maria; O’ Shea, Nora; Gallagher, Eimear; Lafarga, Tomas; Teagasc Walsh Fellowship; Irish Department of Agriculture, Food and Marine (DAFM); Spanish Ministry of Economy, Industry, and Competitiveness; 2016073; FIRM 11/SF/317; et al. (Multidisciplinary Digital Publishing Institute, 2017-12-04)
      The renin-angiotensin-aldosterone system (RAAS) plays an important role in regulating hypertension by controlling vasoconstriction and intravascular fluid volume. RAAS itself is largely regulated by the actions of renin (EC 3.4.23.15) and the angiotensin-I-converting enzyme (ACE-I; EC 3.4.15.1). The enzyme dipeptidyl peptidase-IV (DPP-IV; EC 3.4.14.5) also plays a role in the development of type-2 diabetes. The inhibition of the renin, ACE-I, and DPP-IV enzymes has therefore become a key therapeutic target for the treatment of hypertension and diabetes. The aim of this study was to assess the bioactivity of different oat (Avena sativa) protein isolates and their ability to inhibit the renin, ACE-I, and DPP-IV enzymes. In silico analysis was carried out to predictthe likelihood of bioactive inhibitory peptides occurring from oat protein hydrolysates following in silico hydrolysis with the proteases papain and ficin. Nine peptides, including FFG, IFFFL, PFL, WWK, WCY, FPIL, CPA, FLLA, and FEPL were subsequently chemically synthesised, and their bioactivities were confirmed using in vitro bioassays. The isolated oat proteins derived from seven different oat varieties were found to inhibit the ACE-I enzyme by between 86.5 ± 10.7% and 96.5 ± 25.8%, renin by between 40.5 ± 21.5% and 70.9 ± 7.6%, and DPP-IV by between 3.7 ± 3.9% and 46.2 ± 28.8%. The activity of the synthesised peptides was also determined.
    • Rapid Communication: Large exploitable genetic variability exists to shorten age at slaughter in cattle

      Berry, D. P.; Cromie, A. R.; Judge, M. M. (Oxford University Press (OUP), 2017-10-01)
      Apprehension among consumers is mounting on the efficiency by which cattle convert feedstuffs into human edible protein and energy as well as the consequential effects on the environment. Most (genetic) studies that attempt to address these issues have generally focused on efficiency metrics defined over a certain time period of an animal’s life cycle, predominantly the period representing the linear phase of growth. The age at which an animal reaches the carcass specifications for slaughter, however, is also known to vary between breeds; less is known on the extent of the within-breed variability in age at slaughter. Therefore, the objective of the present study was to quantify the phenotypic and genetic variability in the age at which cattle reach a predefined carcass weight and subcutaneous fat cover. A novel trait, labeled here as the deviation in age at slaughter (DAGE), was represented by the unexplained variability from a statistical model, with age at slaughter as the dependent variable and with the fixed effects, among others, of carcass weight and fat score (scale 1 to 15 scored by video image analysis of the carcass at slaughter). Variance components for DAGE were estimated using either a 2-step approach (i.e., the DAGE phenotype derived first and then variance components estimated) or a 1-step approach (i.e., variance components for age at slaughter estimated directly in a mixed model that included the fixed effects of, among others, carcass weight and carcass fat score as well as a random direct additive genetic effect). The raw phenotypic SD in DAGE was 44.2 d. The genetic SD and heritability for DAGE estimated using the 1-step or 2-step models varied from 14.2 to 15.1 d and from 0.23 to 0.26 (SE 0.02), respectively. Assuming the (genetic) variability in the number of days from birth to reaching a desired carcass specifications can be exploited without any associated unfavorable repercussions, considerable potential exists to improve not only the (feed) efficiency of the animal and farm system but also the environmental footprint of the system. The beauty of the approach proposed, relative to strategies that select directly for the feed intake complex and enteric methane emissions, is that data on age at slaughter are generally readily available. Of course, faster gains may potentially be achieved if a dual objective of improving animal efficiency per day coupled with reduced days to slaughter was embarked on.
    • Mitigating Nutrition and Health Deficiencies in Older Adults: A Role for Food Innovation?

      Baugreet, Sephora; Hamill, Ruth M.; Kerry, Joseph P.; McCarthy, Sinéad N.; Teagasc; Department of Agriculture, Food and the Marine; 11F045 (Wiley, 2017-03-07)
      The aim of this review is to describe the factors contributing to diminished food intake, resulting in nutritional deficiencies and associated health conditions in older adults and proposes food innovation strategies to mitigate these. Research has provided convincing evidence of a link between healthy eating patterns and healthy aging. There is a need to target new food product development (NPD) with functional health benefits specifically designed to address the particular food-related needs of older consumers. When developing foods for older adults, consideration should be given to the increased requirements for specific macro- and micronutrients, especially protein, calcium, vitamin D, and vitamin B. Changes in chemosensory acuity, chewing difficulties, and reduced or poor swallowing ability should also be considered. To compensate for the diminished appetite and reduced intake, foods should be energy dense, nutritionally adequate, and, most importantly, palatable, when targeting this cohort. This paper describes the potential of new food product development to facilitate dietary modification and address health deficiencies in older adults.
    • Molecular characterization of Ralstonia solanacearum strains from Ethiopia and tracing potential source of bacterial wilt disease outbreak in seed potatoes

      Abdurahman, A.; Griffin, D.; Elphinstone, J.; Struik, P. C.; Schulz, S.; Schulte‐Geldermann, E.; Sharma, K.; Walsh Fellowship of Teagasc -Ireland; US Agency for International Development (USAID); Centre for Crop Systems Analysis of Wageningen University; et al. (Wiley, 2017-02-06)
      Bacterial wilt, caused by Ralstonia solanacearum, is emerging as a major threat to potato production in Ethiopia, reaching epidemic proportions in the Chencha district recently, with a prevalence of 97% of potato fields in 2015. The recent disease outbreak in the district coincided with a significant introduction of seed potatoes. This research was therefore initiated to genetically characterize the pathogen so as to trace its source, identify its relationship with outbreaks in the rest of the country, and make intervention recommendations. Ralstonia solanacearum isolates were sampled both from seed and ware potato fields in Chencha and from seed potato fields in production regions suspected of being potential sources of the pathogen. Multiplex PCR and phylogenetic analysis of partial endoglucanase gene sequences identified all of the isolates as phylotype IIB sequevar 1. VNTR sequence analysis distinguished 11 different haplotypes, nine of which were unique to the Chencha district. However, one of the haplotypes was common to all seed potato producer regions of Ethiopia except for the Shashemene area. The unique and diverse VNTR haplotypes of the pathogen in Chencha indicates that it is well established in the district. When a geographical map of the VNTR haplotypes was superimposed with the main cross-regional seed potato distribution pattern of the country, it became evident that the pathogen was being disseminated via latently infected seed from the Holeta-Jeldu area in the Central Highlands of Ethiopia. Identification of largely uninfected highland districts and multiplication of high-grade seed potato exclusively in those districts should be given priority.
    • Preliminary characterization of a novel β-agarase from Thalassospira profundimonas

      Zeng, Cheng; Zhang, Longtao; Miao, Song; Zhang, Yi; Zeng, Shaoxiao; Zheng, Baodong; Regional Demonstration of Marine Economy Innovative Development Project; the Science and Technology Plan of Fujian Province; China Scholarship for Visiting Scholar; 12PYY001SF08; et al. (Springer Science and Business Media LLC, 2016-07-15)
      Background The objective of this study was to characterize the agarase from a newly isolated agarolytic bacterium Thalassospira profundimaris fst-13007. Results Agarase-fst was purified to homogeneity which apparent molecular weight was 66.2 kDa. Its activity was optimal at 45 °C and pH 8 and was stable at pH 5–9 or 30–50 °C. Agarase-fst required Mn2+ for agarase activity and inhibition by Cu2+, Fe3+ and EDTA. Tests of hydrolysis pattern and substrate specificity, TLC analysis and mass spectrometry of the hydrolysis products revealed that it is an endo-type β-agarase hydrolyzing agarose into neoagarobiose, neoagarotetraose and neoagarohexaose. Results of MALDI-TOF-TOF/MS indicate that it lack of homology to previously identified proteins and present conserved domain of β-agarase. Conclusion Agarase-fst from T. profundimaris fst-13007 was confirmed to be a novel endo-type β-agarase.
    • Limitation of Grassland Productivity by Low Temperature and Seasonality of Growth

      Wingler, Astrid; Hennessy, Deirdre (Frontiers Media SA, 2016-07-27)
      The productivity of temperate grassland is limited by the response of plants to low temperature, affecting winter persistence and seasonal growth rates. During the winter, the growth of perennial grasses is restricted by a combination of low temperature and the lack of available light, but during early spring low ground temperature is the main limiting factor. Once temperature increases, growth is stimulated, resulting in a peak in growth in spring before growth rates decline later in the season. Growth is not primarily limited by the ability to photosynthesize, but controlled by active regulatory processes that, e.g., enable plants to restrict growth and conserve resources for cold acclimation and winter survival. An insufficient ability to cold acclimate can affect winter persistence, thereby also reducing grassland productivity. While some mechanistic knowledge is available that explains how low temperature limits plant growth, the seasonal mechanisms that promote growth in response to increasing spring temperatures but restrict growth later in the season are only partially understood. Here, we assess the available knowledge of the physiological and signaling processes that determine growth, including hormonal effects, on cellular growth and on carbohydrate metabolism. Using data for grass growth in Ireland, we identify environmental factors that limit growth at different times of the year. Ideas are proposed how developmental factors, e.g., epigenetic changes, can lead to seasonality of the growth response to temperature. We also discuss perspectives for modeling grass growth and breeding to improve grassland productivity in a changing climate.