Draft Genome Sequence of the Biofilm-Forming Stenotrophomonas maltophilia Strain 53

A clinical strain of Stenotrophomonas maltophilia (designated strain 53) was obtained, and a whole-genome sequence was generated. The subsequent draft whole-genome sequence demonstrated the presence of a number of genes encoding for proteins involved in resistance to a number of antimicrobial therapie

Draft Genome Sequence of an Alkaliphilic Exiguobacterium sp Strain HUD, Isolated from a Polymicrobial Consortia

An alkaliphilic microorganism from the genus Exiguobacterium, Exiguobacterium sp. strain HUD was isolated from a fermentative, methanogenic polymicrobial microcosm operating at pH 10. The draft genome shows the presence of genes encoding for the metabolism of a range of carbohydrates under both aerobic and anaerobic conditions

Draft Genome Sequences of Pseudomonas aeruginosa Strain PS3 and Citrobacter freundii Strain SA79 Obtained from a Wound DressingAssociated Biofilm

Two isolates, one from the genus Pseudomonas and the second from Citrobacter, were isolated from a wound dressing-associated biofilm. Following whole-genome sequencing, the two isolates presented genes encoding for resistance to antibiotics and those involved in exopolysaccharide productio

The cross-contamination potential of mobile telephones

The use of mobile devices for professional, business, educational, personal and social purposes has accelerated exponentially over the last decade. Staff working in healthcare organisations, and patients and visitors using healthcare settings, understandably want to use mobile technology. Concerns have been raised about safety in terms of interference with equipment, and threats to privacy and dignity, yet less policy attention has been paid to infection risks. Healthcare professional students were supplied with smartphones as part of a larger educational project. Devices collected from a sub-sample of students working in operating theatre contexts were sampled to estimate the cross-contamination potential of the technology. A longitudinal multiple measures design was used. Under laboratory conditions, samples were taken from surfaces using swabbing techniques followed by contact plating. The devices were subsequently cleaned with 70% isopropyl alcohol and returned to the students. All devices demonstrated microbial contamination and over three quarters (86%) polymicrobial contamination. The technique and sites used to sample for microbial contamination influenced the levels of contamination identified. Swabbing alone was less likely to isolate polymicrobial contamination than contact plating, and some microorganisms were isolated only by contact plates and not by swabbing of the same area. The findings from this study demonstrate further research is urgently needed to inform evidence-based infection control policy on the use of personal equipment such as mobile devices in the healthcare settings where contamination may have adverse effects on patients, staff and visitors

An approach to modelling the impact of 14C release from reactor graphite in a geological disposal facility

Carbon-14 (C-14) is a key radionuclide in the assessment of a geological disposal facility (GDF) for radioactive waste. In the UK a significant proportion of the national C-14 inventory is associated with reactor core graphite generated by the decommissioning of the UK’s Magnox and AGR reactors. There are a number of uncertainties associated with the fate and transport of C-14 in a post-closure disposal environment that need to be considered when calculating the radiological impacts of C-14 containing wastes. Some of these uncertainties are associated with the distribution of C-14 containing gaseous species such as 14CH4 and 14CO2 between the groundwater and gaseous release pathways. As part of the C14-BIG programme, a modelling framework has been developed to investigate these uncertainties. This framework consists of a biogeochemical near-field evolution model, incorporating a graphite carbon-14 release model, which interfaces with a geosphere/biosphere model. The model highlights the potential impact of the microbial reduction of 14CO2 to 14CH4, through the oxidation of H2, on C-14 transport. The modelling results could be used to inform the possible segregation of reactor graphite from other gas generating wastes

Draft Whole-Genome Sequence of the Alkaliphilic Alishewanella aestuarii Strain HH-ZS, Isolated from Historical Lime Kiln WasteContaminated Soil

Here, we present the whole-genome sequence of an environmental Gram-negative Alishewanella aestuarii strain (HH-ZS), isolated from the hyperalkaline contaminated soil of a historical lime kiln in Buxton, United Kingdom

Biodegradation of Anaerobic, Alkaline Cellulose Degradation Products

The proposed strategy for the disposal of the United Kingdom’s nuclear waste inventory is placement within a deep geological disposal facility (GDF). The prevailing conditions of a GDF are expected to be anaerobic, with alkaline conditions (10.513) over a long timescale. In these anaerobic, alkaline conditions the cellulosic components of intermediate level wastes are expected to degrade, with the major products being the α- and β-forms of isosaccharinic acid (ISA). ISAs have received particular attention because of their ability to form complexes with radionuclides, potentially influencing their migration through the GDF. The potential for microbial colonisation of a GDF means that ISAs present a source of organic carbon for utilisation. The ability of micro-organisms to utilise cellulose degradation products including ISA is poorly understood. The work presented in this thesis has shown that near surface microbial consortia are capable of the degradation of ISA under iron reducing, sulphate reducing and methanogenic conditions at circumneutral pH values expected within geochemical niches of the near field and far field of a facility, with PCR analysis suggesting groups responsible for these metabolic processes were present in each instance. The same near surface consortium studied was capable of ISA degradation up to a pH of 10 within 8 weeks. Degradation rates were retarded by the increase in pH, in particular that of the β- stereoisomer. Clostridia were the likely bacterial Class responsible for fermentation of ISA to acetic acid, carbon dioxide and hydrogen. These secondary metabolites were then used in the generation of methane by methanogenic Archaea, however the acetoclastic methanogen component of the consortium was absent at elevated pH; evidenced by the persistence of acetic acid within the microcosm chemistry. The mesophilic consortium used in these initial investigations was not capable of ISA degradation above pH 10 within the short timescales imposed within the project. As a result, a soil consortium was obtained from a hyper alkaline contaminated site, where waste products from lime burning had occurred between 1883 and 1944. Initial surveying of the site showed that ISA was present and generated through interactions between the hyperalkaline leachate and organic soil matter. Following sub-culture of the soil consortia at pH 11, complete ISA degradation was observed within 14 days where again, fermentation processes followed by methanogenesis occurred. Clone libraries showed that again Clostridia was the dominant phylogenetic Class, represented by species from the genus Alkaliphilus. As observed with the mesophilic microcosms at pH 10, hydrogenotrophic methanogens dominated the Archaeal components of the consortia. The results presented in the following body of work suggest that the microbial colonisation of a GDF is likely within the construction and operational phases of the facility. Carbon dioxide is likely to be the predominant terminal electron acceptor within the facility and here methanogenesis has been observed up to a pH of 11.0. In each case, fermentation is likely to be as a result of alkaliphilic Clostridia, where methanogenesis appears to be limited to the hydrogenotrophic pathway at elevated pH. These findings are likely to inform safety assessments through both the application of rate data and gas generation predictions

Whole genome sequence of the anaerobic isosaccharinic acid degrading isolate, Macellibacteroides fermentans strain HH-ZS

The ability of micro-organisms to degrade isosaccharinic acids (ISAs) whilst tolerating hyperalkaline conditions is pivotal to our understanding of the biogeochemistry associated within these environs, but also in scenarios pertaining to the cementitious disposal of radioactive wastes. An alkalitolerant, ISA degrading micro-organism was isolated from the hyperalkaline soils resulting from lime depositions. Here we report the first whole genome sequence, ISA degradation profile and carbohydrate preoteome of a Macellibacteroides fermentans strain HH-ZS, 4.08Mb in size, coding 3,241 proteins, 64 tRNA and one rRNA

Hydrogenotrophic Methanogenesis Under Alkaline Conditions

A cement-based geological disposal facility (GDF) is one potential option for the disposal of intermediate level radioactive wastes. The presence of both organic and metallic materials within a GDF provides the opportunity for both acetoclastic and hydrogenotrophic methanogenesis. However, for these processes to proceed, they need to adapt to the alkaline environment generated by the cementitious materials employed in backfilling and construction. Within the present study, a range of alkaline and neutral pH sediments were investigated to determine the upper pH limit and the preferred route of methane generation. In all cases, the acetoclastic route did not proceed above pH 9.0, and the hydrogenotrophic route dominated methane generation under alkaline conditions. In some alkaline sediments, acetate metabolism was coupled to hydrogenotrophic methanogenesis via syntrophic acetate oxidation, which was confirmed through inhibition studies employing fluoromethane. The absence of acetoclastic methanogenesis at alkaline pH values (>pH 9.0) is attributed to the dominance of the acetate anion over the uncharged, undissociated acid. Under these conditions, acetoclastic methanogens require an active transport system to access their substrate. The data indicate that hydrogenotrophic methanogenesis is the dominant methanogenic pathway under alkaline conditions (>pH 9.0)