Publications

Dataset for: Quantifying citrate-enhanced phosphate root uptake using microdialysis

Dataset supporting the publication: Quantifying citrate-enhanced phosphate root uptake using microdialysis, McKay Fletcher, D. M. et al (2019) in the Journal Plant and soil

Competition for amino acids between wheat roots and rhizosphere microorganisms and the role of amino acids in plant N acquisition

The direct uptake of organic nitrogen compounds from the soil solution by plant roots has been hypothesised to constitute a significant source of N to the plant particularly in N limiting ecosystems. The experiments undertaken here were designed to test whether wheat roots could out-compete the rhizosphere microflora for a pulse addition of organic N in the form of three contrasting amino acids, namely lysine, glycine and glutamate. Amino acids were added at a concentration reflecting reported soil solution concentrations (100μM) and the uptake into either plant biomass or respiration or microbial biomass and respiration determined over a 24h chase period. The results showed that the plant roots could only capture on average 6% of the added amino acid with the remainder captured by the microbial biomass. We therefore present direct in vivo evidence to support earlier work which has hypothesised that organic N may be of only limited consequence in high input agricultural systems. We suggest that this is a result of the higher concentrations of NO3 − in agricultural soil solutions, the slow movement of amino acids in soil relative to NO3 −, the rapid turnover of amino acids by soil microorganisms, and the poor competitive ability of plant roots to capture amino acids from the soil solution.

International Committee on Systematic Bacteriology Subcommittee on the Taxonomy of Listeria, Brochothrix, and Erysipelothrix: Minutes of the Meetings, 4 and 7 July 1994, Prague, Czech Republic

Microbiology Society journals contain high-quality research papers and topical review articles. We are a not-for-profit publisher and we support and invest in the microbiology community, to the benefit of everyone. This supports our principal goal to develop, expand and strengthen the networks available to our members so that they can generate new knowledge about microbes and ensure that it is shared with other communities.

A Stable Bioluminescent Construct of <i>Escherichia coli</i> O157:H7 for Hazard Assessments of Long-Term Survival in the Environment

A chromosomally lux- marked (Tn 5 luxCDABE ) strain of nontoxigenic Escherichia coli O157:H7 was constructed by transposon mutagenesis and shown to have retained the O157, H7, and intimin phenotypes . The survival characteristics of this strain in the experiments performed (soil at −5, −100, and −1,500 kPa matric potential and artificial groundwater) were indistinguishable from the wild-type strain. Evaluation of potential luminescence was found to be a rapid, cheap, and quantitative measure of viable E. coli O157:H7 Tn 5 luxCDABE populations in environmental samples. In the survival studies, bioluminescence of the starved populations of E. coli O157:H7 Tn 5 luxCDABE could be reactivated to the original levels of light emission, suggesting that these populations remain viable and potentially infective to humans. The attributes of the construct offer a cheap and low-risk substitute to the use of verocytotoxin-producing E. coli O157:H7 in long-term survival studies.

Impact of Sediment Concentration on the Survival of Wastewater-Derived blaCTX-M-15-Producing E. coli, and the Implications for Dispersal into Estuarine Waters

The environmental cycling of antibiotic-resistant blaCTX-M-15-producing E. coli following release from wastewater treatment plants is a major public health concern. This study aimed to (i) assess the impact of sediment concentrations on the rate of their inactivation following release from human wastewater into freshwater, and (ii) simulate their subsequent dispersal to the nearby coastline during a "worst-case" event where heavy rainfall coincided with high spring tide in the Conwy Estuary, North Wales. Freshwater microcosms of low, medium and high turbidity were inoculated with blaCTX-M-15 -producing E. coli, then exposed to ultraviolet (UV) radiation. Typical regional wintertime exposure to UV was found to be insufficient to eradicate E. coli, and in highly turbid water, many bacteria survived simulated typical regional summertime UV exposure. Modelling results revealed that blaCTX-M-15-producing E. coli concentrations reduced downstream from the discharge source, with ~ 30% of the source concentration capable of dispersing through the estuary to the coast, taking ~36 h. Offshore, the concentration simulated at key shellfisheries and bathing water sites ranged from 1.4% to 10% of the upstream input, depending on the distance offshore and tidal regime, persisting in the water column for over a week. Our work indicates that the survival of such organisms post-release into freshwater is extended under typical wintertime conditions, which could ultimately have implications for human health.

Microbiological quality of chicken wings damaged on the farm or in the processing plant

Selling of damaged chicken wings (those with bone protrusion) for human consumption is prohibited in the European Union on the grounds of possible risks to human health arising from microbial contamination. Standard food industry tests were used to assess different categories of chicken wings (undamaged, farm damaged and factory damaged; n = 264) for, coliforms, Enterobacteriaceae, total viable counts, Pseudomonas spp., Staphylococcus aureus and Salmonella spp. No significant differences in bacterial numbers existed among wings belonging to the three categories. Only low numbers of bacteria were found throughout, and 97% of all results would pass the standards of a leading UK retailer. These results were strengthened by a longitudinal survey of wing breakage, which showed almost all wing puncturing occurred during the de-feathering process, limiting the likelihood of microbial contamination. Combined, these results indicate there is no increased health risk from consumption of damaged, compared to undamaged, chicken wings. The existing imposed regulations may therefore be an unnecessary burden on the poultry industry.

High optical gain in iron doped lithium niobate by contradirectional two beam coupling

Two beam coupling is the process whereby two beams of light at similar frequencies are coupled together resulting in energy transfer from one beam to the other. The mechanism responsible for the coupling is a diffraction grating written within a photorefractive crystal.

Ocean warming increases the nitrogen demand and the uptake of organic nitrogen of the globally distributed seagrass <i>Zostera marina</i>

The impact of global warming on the metabolic state of a species may be examined by either measuring physiological rates across a latitudinal gradient or by assessing short‐term responses under experimentally controlled temperature regimes. The combination of the two approaches is seldom used but it provides valuable information on an organism's responses to temperature at broader temporal and spatial scales while allowing the isolation of temperature effects from other environmental variables. Here we used both approaches to assess the warming effects on the total acquisition of dissolved inorganic nitrogen (DIN; nitrate, ammonium) and organic N (DON; amino acids, peptides) by the globally widespread seagrass Zostera marina . DIN and DON uptake rates were measured in plants from three sites covering the species latitudinal distribution in Europe (Iceland, UK and Portugal). The responses of DIN and DON uptake rates of plants from the middle latitude (UK) to a latitudinal range of temperatures (8, 12 and 17°C) were also measured. We further examined the microbial uptake of DON along the latitudinal distribution and whether temperature is the main driver of that uptake. Our results showed that warming greatly increased the total N uptake by Z. marina and also the relative contribution of DON to total N acquisition. The microbial uptake of DON increased towards warmer latitudes, and temperature was the main driver of these observations. Ocean warming will increase the nitrogen demand of Z. marina and this demand may be met by an increasing uptake of organic nitrogen forms. This indicates that Z. marina , and probably other seagrass species, can be winners under global change as nitrogen uptake capacity will not limit growth driven by increased photosynthetic assimilation of CO 2 . A free Plain Language Summary can be found within the Supporting Information of this article.

Automated Airborne Ordinance Detection Using Data Fusion of Magnetometer and Ground Penetrating Radar

Landmines pose a critical threat to human and animal lives in post-conflict regions and continue to hinder economic recovery by affecting agriculture and infrastructure development. The process of discovering and clearing ordnance involving landmines using human or animal forces presents extreme risks and demands a considerable labour force and time. Landmines are made from a variety of materials, including wood, glass, metal, and plastic, and they vary in size. To improve detection accuracy, multiple sensors with different capabilities can be used simultaneously, allowing for data fusion and more informed decision-making. The use of uninhabited aerial vehicles (UAVs) equipped with diverse remote sensing technologies offers a safe and efficient means of accelerating humanitarian demining operations. In this study, two integrated remote sensing modalities - Ground-Penetrating Radar (GPR) and magnetometers - are mounted on an advanced autonomous UAV to enhance detection probability and reduce false alarm rates. A custom Android-based tablet application is used to analyse the fused data in real time. The performance of the individual sensing modalities was evaluated through field tests conducted in Latvia, Croatia, and Cambodia. The complete integrated system, incorporating sensor data fusion, was tested in a landmine field in the UK. Results from these outdoor trials confirm the effectiveness of the proposed fusion techniques in detecting legacy landmines, Unexploded Ordnance (UXO) and Improvised Explosive Devices (IEDs) with high accuracy.

A New Australian Corybas (Orchidaceae) Previously Misinterpreted as C. diemenicus (Lindley) H. G. Reichb.

Responsible agriculture must adapt to the wetland character of mid‐latitude peatlands

Drained, lowland agricultural peatlands are greenhouse gas (GHG) emission hotspots and a large but vulnerable store of irrecoverable carbon. They exhibit soil loss rates of ~2.0 cm yr-1 and are estimated to account for 32% of global cropland emissions while producing only 1.1% of crop kilocalories. Carbon dioxide emissions account for >80% of their terrestrial GHG emissions and are largely controlled by water table depth. Reducing drainage depths is, therefore, essential for responsible peatland management. Peatland restoration can substantially reduce emissions. However, this may conflict with societal needs to maintain productive use, to protect food security and livelihoods. Wetland agriculture strategies will, therefore, be required to adapt agriculture to the wetland character of peatlands, and balance GHG mitigation against productivity, where halting emissions is not immediately possible. Paludiculture may substantially reduce GHG emissions but will not always be viable in the current economic landscape. Reduced drainage intensity systems may deliver partial reductions in the rate of emissions, with smaller modifications to existing systems. These compromise systems may face fewer hurdles to adoption and minimize environmental harm until societal conditions favour strategies that can halt emissions. Wetland agriculture will face agronomic, socio-economic and water management challenges, and careful implementation will be required. Diversity of values and priorities among stakeholders creates the potential for conflict. Successful implementation will require participatory research approaches and co-creation of workable solutions. Policymakers, private sector funders and researchers have key roles to play but adoption risks would fall predominantly on land managers. Development of a robust wetland agriculture paradigm is essential to deliver resilient production systems and wider environmental benefits. The challenge of responsible use presents an opportunity to rethink peatland management and create thriving, innovative and green wetland landscapes for everyone's future benefit, while making a vital contribution to global climate change mitigation.

The long-term uncertainty of biodegradable mulch film residues and associated microplastics pollution on plant-soil health

Biodegradable mulch film potentially offers an encouraging alternative to conventional (petroleum-based) plastic films. Since biodegradable films are more susceptible to rapid degradation, more microplastics (MPs) are likely to be generated than conventional films within the same time frame, probably leading to more severe MPs pollution and associated effects. However, the effect of biodegradable mulch film residues and associated MPs pollution on plant-soil health remains uncertainty. Here, we evaluated the potential effect of bio-MPs pollution on soil carbon (C) and nutrient (i.e., N and P) cycling, soil biology (microorganisms and mesofauna), and plant health, as these are crucial to agroecosystem functioning and the delivery of key ecosystem services. Unlike the inert (and therefore recalcitrant) C contained within petroleum-based MPs, at least 80% of the C from bio-MPs is converted to CO2, with up to 20% immobilized in living microbial biomass (i.e., < 0.05 t C ha−1). Although biodegradable films are unlikely to be important in promoting soil C storage, they may accelerate microbial biomass turnover in the short term, as well as CO2 production. Compared to conventional MPs, bio-MPs degradation is more pronounced, thereby inducing greater alterations in microbial diversity and community composition. This may further alter N2O and CH4 emissions, and ultimately resulting in unpredictable consequences for global climate warming. The extent to which this may occur, however, has yet to be shown in either laboratory or field studies. In addition, bio-MPs have a large chance of forming nanoplastics, potentially causing a stronger toxic effect on plants relative to conventional MPs. Consequently, this would influence plant health, crop productivity, and food safety, leading to potential health risks. It is unclear, however, if these are direct effects on key plant processes (e.g. signaling, cell expansion) or indirect effects (e.g. nutrient deficiency or acidification). Overall, the question as to whether biodegradable mulch films offer a promising alternative to solve the conventional plastic legacy in soil over the long term remains unclear.

Agronomic amendments drive a diversity of real and apparent priming responses within a grassland soil

Soil carbon (C) sequestration is often viewed as a nature-based solution to help mitigate climate change. Key to realising this potential is a better understanding of which C inputs promote greater long-term C storage. The priming effect (PE) is the change in rates of microbial soil organic matter (SOM) decomposition caused by the addition of organic or mineral amendments to soil. The apparent PE (changes in CO2 from microbial biomass turnover) of substrates is often studied as a confounding factor, however, the real PE (decomposition of native SOM) is rarely measured due to uncertainties in C pool differentiation. Here, we used a 50-day mesocosm study to compare the effect of various common soil amendments (wood biochar and ash, protein, amino acids, glucose, cellulose, cattle farmyard manure (FYM), cattle slurry, inorganic N fertiliser, and different ratios of wheat straw:shoot mixes) on the real and apparent PEs of soil, using 5-year old quasi-stable 14C-labelled SOM and 14C-labelled active microbial biomass, respectively. Our results show that there are often significant differences in the real and apparent PE, for the same amendment, with variance in magnitude and, in some case, direction. We identified few consistent drivers of PE across the two assays, however, there was a negative relationship between the initial C:N ratio of the treatment and PEs, suggesting that while the nutrient stoichiometry of the C amendment is important, the usability and quality of the substrate for the microbial community are key to determining its priming response. Equally, context is important for interpretation, as treatments that illicit positive priming may still be replenishing or increasing soil C stocks.

Five-year carry-over effects in dune slack vegetation response to hydrology

Dune slacks are biodiverse seasonal wetlands within sand dune systems, strongly influenced by the dynamics of the local groundwater regime. Future climate predictions indicate strong adverse impact on the hydrology and therefore ecology of these wetland ecosystems. In this study we aimed to find the most appropriate hydrological and ecological indicators to summarise dune slack plant community responses to hydrology over multiple years. We evaluated 80 hydrological metrics (weighted and un-weighted median, mean, minimum, maximum, mean spring level, averaged over 1–8 year duration, and 5 additional 1-year metrics) against plant community responses (variants of Ellenberg EbF moisture indicator). The data were drawn from 453 relevées in 17 dune slacks, using permanent quadrats and co-located piezometers, set up in 2010 with vegetation monitoring repeated six times until 2019. Within our study we found a strong relationship between multiple hydrology metrics and the plant community response, but this displayed inter-annual variation with different patterns and correlations between years. The best performing hydrology metric was the unweighted 5-year average mean spring water level (MSL), linked to unweighted mean EbF using vascular plant species only. Maximum water level (MAX) also performed well, but MSL was preferred as MAX can be enhanced or truncated by topography leading to anomalies for individual slacks. MSL is also flexible to implement within manual monitoring programmes, which could be targeted to 3-months per year over the spring as a minimum requirement. These findings provide simpler metrics for site managers to monitor potential hydrology and vegetation responses to climate change.

Soil microbial adaptation to carbon deprivation: shifts in lignocellulolytic gene profiles following long-term plant exclusion

Together our data show that extracellular lignin degrading enzymes increase under long-term plant exclusion. There is now a need for increased focus on the microbial metabolic mechanisms which regulate the processing and persistence of enzymatically released compounds, particularly in energy limited soils.

Evaluating the Potential Risks of Inorganic and Organic Additive Release from Agricultural Plastic Mulch Film

No abstract is provided for this article.

Epizoic Barnacles Act as Pathogen Reservoirs on Shellfish Beds

Bivalve shellfish are well-known vectors for human pathogens. Recent research on commercial shellfish beds has shown that the bacterial reservoir contained within the shellfish flesh in situ is often not representative of the microbial quality of the shellfish at the point of sale. This study investigates whether barnacles living on the surface of mussels represent a potential bacterial reservoir within shellfish beds and assesses their potential as a vector for human pathogen transfer. Barnacle and mussel samples were collected from 3 independent intertidal mussel (Mytilus edulis Linnaeus, 1758) beds and subjected to standard microbiological testing and ecological evaluation. Our results show that coliform concentrations were significantly higher in barnacles than in the corresponding mussels, per unit area, across all surveyed sites. The dominant observed barnacle species was the invasive barnacle Austrominius (Elminius) modestus (Darwin, 1854) which has outcompeted native species in the region and contains increased coliform bacterial concentrations relative to other observed barnacle species. This study concludes that, where present, epizoic barnacles represent a significant reservoir for bacteria within shellfish beds and, therefore, have the capacity to act as vectors for human pathogens. Further work is needed to quantify the subsequent viability/pathogenicity of the epizoic bacterial reservoir after shellfish harvesting and food processing.

Rezensionen

Das Thema des Literaturhistorikers und Kritikers Rutherford ist das Heldentum und seine Wiedergabe und Interpretation bei den Autoren Kipling, T. E. Lawrence (of Arabia), Waugh und Le Carre.In einem weiteren Kapitel befaßt er sich mit Werken, die den Krieg in Frankreich 1914-1918 behandeln (»The Common Man as Hero«).Aldous Huxley hatte bereits in »Brave New World« seinen Mustapha Mond erklären lassen, daß die neuzeitliche Zivilisation weder Adel noch Helden benötige, denn beides bringe nur Instabilität mit sich.Diese -den dreißiger Jahren entstammende Erkenntnisist in jüngster Zeit wieder zunehmend in Frage gestellt worden, obwohl die moderne Literatur die Problematik bzw.die dahintersteckende (Sehn-)Sucht zu negieren scheint.Allerdings befindet sie sich in offensichtlichem Einklang mit der Teilnahmslosigkeit der westlichen, zumal der bundesrepublikanischen Wohlstandsgesellschaft, auf die John Baynes' Verdikt -von Rutherford eingangs zitiert -zutrifft: »A society that loses courage can only fade and crumble away.«Im Mittelpunkt des Essays über Kipling und den »Frontier War« steht der einzelne, einfache Mann, der Subalterne, dessen Situation »in the quarrels of civilised nations« Winston Churchill einmal folgendermaßen umrissen hat: »In all this tumult, this wholesale slaughter, the individual and his feelings are utterly lost, only the army has a tale to tell'.«(S. 11) Smollet und Dibdin haben einer lesenden Öffentlichkeit das Leben in der englischen Marine nahegebracht.Der Alltag des gemeinen Mannes in der Army dagegen blieb lange unbekannt, zumal sie im 18. und 19.Jahrhundert sozusagen neben dem »normalen« nationalen Leben existierte.Kipling mit seinen Geschichten und Gedichten von der Grenze, der Front, der Offiziersmesse und den Kasernen füllte diese Lücke.Dabei hatte er das literarisch-methodische Dilemma zu bewältigen, seinen Stoff angemessen darzustellen.Zwischen heroisierender Romantik und nacktem Realismus steuerte er einen Mittelweg und schuf die »Realitätsromanze« (S. 16).Der Burenkrieg erhöhte die Bedeutung des Militärs im Denken Kiplings und vieler Zeitgenossen; Verteidigungsprobleme beschäftigten ihn nun verstärkt.In bitteren Versen (etwa: The Islanders; The Dykes; The Army of a Dream) warnte er davor, unvorbereitet in das Armageddon einzutreten.Der Kampf zwischen Zivilisation und Anarchie beherrschte sein Denken; law and order waren für ihn unantastbare Werte (der Zivilisation).Kiplings Sohn, ein kaum achtzehnjähriger Leutnant, fiel im Ersten Weltkrieg.Ihm und der Vorkriegswelt des britischen Empire widmete er »The Irish Guards in the Great War«, das er als Denkmal des Mutes verstand und in dem er sich lediglich eine Anspielung erlaubte auf die »many, almost children, of whom no record remains« (S. 37).Während Kipling infolge einer dauernden Augenschwäche nie Soldat sein konnte und daher nur ein intellektueller Typ