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1.
J Plast Reconstr Aesthet Surg ; 74(10): 2443-2457, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34266806

ABSTRACT

BACKGROUND: The role of perioperative radiotherapy in the management of resectable extremity soft tissue sarcoma (ESTS) is widely recognised for local tumour control, wound complications (WC) and long-term function. However, debate continues regarding its implications on long-term survival. This study aimed to determine whether the timing of perioperative radiotherapy affects long-term survival outcomes in adults with ESTS. METHODS: A systematic literature search of MEDLINE, EMBASE, Web of Science and Cochrane was performed. The primary outcome measure was the pooled hazard ratio (HR) at 95% confidence intervals. Secondary outcomes and subgroup analyses were presented as cumulative odds ratios (OR). A random-effects, generic inverse variance method and sensitivity analysis were performed to minimise heterogeneity. RESULTS: Six studies (n = 4192 patients) were identified. Time-to-event analysis demonstrated a statistically significant advantage in post-operative radiotherapy for overall survival (HR 1.15 and p = 0.05). Combined HRs for disease-free (1.25 and p = 0.22) and disease-specific (1.06 and p = 0.43) survival also favoured post-operative radiotherapy but did not achieve statistical significance. Post-operative radiotherapy was shown to confer an overall (OR 1.19 and p = 0.01), disease-free (OR 1.19 and p = 0.01) and disease-specific (OR 1.19 and p = 0.01) survival advantage on subgroup analysis. This survival benefit was best observed at three years in the disease-free survival comparison (OR 1.55 and p = 0.003). Preoperative radiotherapy was associated with more WC (OR 2.74 and p<0.00001). CONCLUSIONS: Pooled analysis of published literature suggests that post-operative radiotherapy confers a significant long-term survival advantage with fewer WC. Further large multicentre randomised controlled trials with long-term follow-up are required to determine the optimal perioperative radiotherapy regime in adult ESTS.


Subject(s)
Extremities , Long Term Adverse Effects , Perioperative Care , Radiotherapy/methods , Sarcoma/radiotherapy , Soft Tissue Neoplasms/radiotherapy , Adult , Cancer Survivors/statistics & numerical data , Extremities/pathology , Extremities/surgery , Humans , Long Term Adverse Effects/mortality , Long Term Adverse Effects/prevention & control , Perioperative Care/methods , Perioperative Care/standards , Sarcoma/mortality , Sarcoma/pathology , Sarcoma/surgery , Soft Tissue Neoplasms/mortality , Soft Tissue Neoplasms/pathology , Soft Tissue Neoplasms/surgery , Time-to-Treatment/standards
2.
J Plast Surg Hand Surg ; 55(4): 232-241, 2021 Aug.
Article in English | MEDLINE | ID: mdl-33356756

ABSTRACT

Introduction: Bibliometric and altmetric analyses are used to identify landmark publications in their respective research field. We hypothesised that highly cited skin oncology articles correlate positively with the Oxford Evidence Based Medicine scoring level, altmetric score (AS) and rank within the top 100 manuscripts.Methods: Thomson Reuter's Web of Science citation indexing database was searched to identify all English-language skin oncology full-text articles in the last 75 years. The top 100 articles with the highest citation count were analysed by subject matter, publishing journal, author, year, institution, individual and five-year impact factor, AS and Oxford EBM level. Results: 180,132 articles were identified. The most cited article (Hodi et al.) demonstrated improved survival with ipilimumab in patients with metastatic melanoma (7894 citations). The article with the highest AS was Esteva et al. (AS = 576.7, 'dermatologist-level classification of skin cancer with deep neural networks'). No difference was found between evidence level and citation count (r = -0.1239, p = 0.2291), but a significant difference was seen for AS (r = -0.3024, p = 0.0028). AS scores increased over time, whereas bibliometrics did not. Conclusion: This work highlights the most influential work in the skin oncology field in the last 75 years. We have identified a differential relationship between commonly used metrics and evidence level in the field of skin oncology. As the digitalisation of research output and consumption increases, both bibliometric and altmetric analyses need to be considered when an article's impact is being assessed.


Subject(s)
Bibliometrics , Publishing , Databases, Factual , Humans
3.
BMJ Open Respir Res ; 6(1): e000426, 2019.
Article in English | MEDLINE | ID: mdl-31321058

ABSTRACT

Background: Predicting patient outcomes following critical illness is challenging. Recent evidence has suggested that patients with blood group AB are more likely to survive following major cardiac surgery, and this is associated with a reduced number of blood transfusions. However, there are no current data to indicate whether a patient's blood group affects general intensive care outcomes. Objective: The objective of this study was to determine if ABO blood group affects survival in intensive care. The primary outcome measure was 90-day mortality with a secondary outcome measure of the percentage of patients receiving a blood transfusion. Design: Retrospective analysis of electronically collected intensive care data, blood group and transfusion data. Setting: General intensive care unit (ICU) of a major tertiary hospital with both medical and surgical patients. Patients: All patients admitted to ICU between 2006 and 2016 who had blood group data available. Intervention: None. Measurements and main results: 7340 patients were included in the study, blood group AB accounted for 3% (221), A 41% (3008), B 10.6% (775) and O 45.4% (3336). These values are similar to UK averages. Baseline characteristics between the groups were similar. Blood group AB had the greatest survival benefit (blood group AB 90-day survival estimate 76.75, 95% CI 72.89 to 80.61 with the overall estimate 72.07, 95% CI 71.31 to 72.82) (log-rank χ2 16.128, p=0.001). Transfusion requirements were similar in all groups with no significant difference between the percentages of patients transfused (AB 23.1%, A 21.5%, B 18.7%, O 19.9%, Pearson χ2 5.060 p=0.167). Conclusion: Although this is primarily a hypothesis generating study, intensive care patients with blood group AB appeared to have a higher 90-day survival compared with other blood groups. There was no correlation between blood group and percentage of patients receiving transfusion.


Subject(s)
ABO Blood-Group System , Critical Illness/mortality , Intensive Care Units/statistics & numerical data , Adult , Aged , Blood Transfusion/statistics & numerical data , Critical Care/statistics & numerical data , Critical Illness/therapy , Female , Hospital Mortality , Humans , Kaplan-Meier Estimate , Length of Stay/statistics & numerical data , Male , Middle Aged , Prognosis , Retrospective Studies , Tertiary Care Centers/statistics & numerical data
4.
iScience ; 12: 260-269, 2019 Feb 22.
Article in English | MEDLINE | ID: mdl-30711749

ABSTRACT

Elucidating the effect of harsh environments on the activities of microorganisms is important in revealing how microbes withstand unfavorable conditions or evolve mechanisms to counteract those effects, many of which involve electron transfer phenomena. Here we show that the non-acidophilic and non-thermophilic Bacillus subtilis is able to maintain activity after being subjected to extreme temperatures (100°C for up to 8 h) and acidic environments (pH = 1.50 for over 2 years). In the process, our results suggest that B. subtilis utilizes an extracellular electron transfer as an electron communication pathway between B. subtilis and the environment that involves the cofactor nicotinamide adenine dinucleotide as an essential participant to maintain viability. Elucidation of the capability of the non-acidophilic and non-thermophilic strain to maintain viability under these extreme conditions could aid in understanding the cell responses to different environments from the perspective of energy conservation pathways.

5.
Mar Pollut Bull ; 133: 506-516, 2018 Aug.
Article in English | MEDLINE | ID: mdl-30041344

ABSTRACT

The behavioural responses of migrating humpback whales to an air gun, a small clustered seismic array and a commercial array were used to develop a dose-response model, accounting for the presence of the vessel, array towpath relative to the migration and social and environmental parameters. Whale groups were more likely to show an avoidance response (increasing their distance from the source) when the received sound exposure level was over 130 dB re 1 µPa2·s and they were within 4 km of the source. The 50% probability of response occurred where received levels were 150-155 dB re 1 µPa2·s and they were within 2.5 km of the source. A small number of whales moving rapidly close to the source vessel did not exhibit an avoidance response at the highest received levels (160-170 dB re 1 µPa2·s) meaning it was not possible to estimate the maximum response threshold.


Subject(s)
Humpback Whale/physiology , Models, Biological , Noise/adverse effects , Animal Migration , Animals , Avoidance Learning , Female , Male
6.
Front Surg ; 4: 68, 2017.
Article in English | MEDLINE | ID: mdl-29238710

ABSTRACT

The Keystone perforator island flap (Keystone flap), is a Type A fasciocutaneous advancement flap, consisting of two V to Y advancement flaps. Skin cancer excision around joints presents a number of reconstructive challenges. Owing to the mobile nature of joints, the optimal periarticular reconstructive option should possess the ability to provide adequate tissue coverage and withstand regional changes in tensile pressures. We report a single-surgeon series of five cases of periarticular keystone flap between 2014 and 2017. Data were collected from operation notes, clinical photography, histopathology, and outpatient clinic records. The indication for keystone flap was skin cancer in all cases (n = 5). The largest defect size post-excision in was 75 mm × 40 mm × 15 mm. All keystone flaps demonstrate a color and cosmetic appearance comparable to adjacent tissue. There were no major postoperative complications including flap failure or impaired range of joint movement in the follow up period. Superficial wound infection occurred postoperatively in one case. This is the first case series to discuss the use of keystone flaps in periarticular wound closure. Locoregional fasciocutaneous wound coverage offered by keystone flaps may alleviate the risks of graft failure, contour defects, and donor site morbidity associated with alternative reconstructive options, with good functional and cosmetic outcomes. We advocate their use as a robust reconstructive option in periarticular areas.

7.
Proc Biol Sci ; 284(1869)2017 Dec 20.
Article in English | MEDLINE | ID: mdl-29237853

ABSTRACT

Despite concerns on the effects of noise from seismic survey airguns on marine organisms, there remains uncertainty as to the biological significance of any response. This study quantifies and interprets the response of migrating humpback whales (Megaptera novaeangliae) to a 3130 in3 (51.3l) commercial airgun array. We compare the behavioural responses to active trials (array operational; n = 34 whale groups), with responses to control trials (source vessel towing the array while silent; n = 33) and baseline studies of normal behaviour in the absence of the vessel (n = 85). No abnormal behaviours were recorded during the trials. However, in response to the active seismic array and the controls, the whales displayed changes in behaviour. Changes in respiration rate were of a similar magnitude to changes in baseline groups being joined by other animals suggesting any change group energetics was within their behavioural repertoire. However, the reduced progression southwards in response to the active treatments, for some cohorts, was below typical migratory speeds. This response was more likely to occur within 4 km from the array at received levels over 135 dB re 1 µPa2s.


Subject(s)
Animal Migration , Humpback Whale/physiology , Noise/adverse effects , Animals , Australia , Female , Male
8.
J Exp Biol ; 220(Pt 16): 2878-2886, 2017 08 15.
Article in English | MEDLINE | ID: mdl-28814610

ABSTRACT

The effect of various anthropogenic sources of noise (e.g. sonar, seismic surveys) on the behaviour of marine mammals is sometimes quantified as a dose-response relationship, where the probability of an animal behaviourally 'responding' (e.g. avoiding the source) increases with 'dose' (or received level of noise). To do this, however, requires a definition of a 'significant' response (avoidance), which can be difficult to quantify. There is also the potential that the animal 'avoids' not only the source of noise but also the vessel operating the source, complicating the relationship. The proximity of the source is an important variable to consider in the response, yet difficult to account for given that received level and proximity are highly correlated. This study used the behavioural response of humpback whales to noise from two different air gun arrays (20 and 140 cubic inch air gun array) to determine whether a dose-response relationship existed. To do this, a measure of avoidance of the source was developed, and the magnitude (rather than probability) of this response was tested against dose. The proximity to the source, and the vessel itself, was included within the one-analysis model. Humpback whales were more likely to avoid the air gun arrays (but not the controls) within 3 km of the source at levels over 140 re. 1 µPa2 s-1, meaning that both the proximity and the received level were important factors and the relationship between dose (received level) and response is not a simple one.


Subject(s)
Behavior, Animal , Humpback Whale/physiology , Noise/adverse effects , Animals , Female , Firearms , Queensland
9.
Front Chem ; 4: 36, 2016.
Article in English | MEDLINE | ID: mdl-27597939

ABSTRACT

Here, we demonstrate that Cobalt/cobalt oxide core-shell nanoparticles integrated on nitrogen-doped (N-doped) three-dimensional reduced graphene oxide aerogel-based architecture (Co/CoO-NGA) were synthesized through a facile hydrothermal method followed by annealing treatment. The unique endurable porous structure could provide sufficient mass transfer channels and ample active sites on Co/CoO-NGA to facilitate the catalytic reaction. The synthesized Co/CoO-NGA was explored as an electrocatalyst for the oxygen reduction reaction, showing comparable oxygen reduction performance with excellent methanol resistance and better durability compared with Pt/C.

10.
Mar Pollut Bull ; 103(1-2): 72-83, 2016 Feb 15.
Article in English | MEDLINE | ID: mdl-26781958

ABSTRACT

'Ramp-up', or 'soft start', is a mitigation measure used in seismic surveys and involves increasing the radiated sound level over 20-40 min. This study compared the behavioural response in migrating humpback whales to the first stages of ramp-up with the response to a 'constant' source, 'controls' (in which the array was towed but not operated) with groups in the absence of the source vessel used as the 'baseline'. Although the behavioural response, in most groups, resulted in an increase in distance from the source (potential avoidance), there was no evidence that either 'ramp-up' or the constant source at a higher level was superior for triggering whales to move away from the source vessel. 'Control' groups also responded suggesting the presence of the source vessel had some effect. However, the majority of groups appeared to avoid the source vessel at distances greater than the radius of most mitigation zones.


Subject(s)
Behavior, Animal , Humpback Whale/physiology , Noise , Animals , Australia , Environmental Exposure , Female , Male
11.
Mol Cell Neurosci ; 69: 12-21, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26370173

ABSTRACT

Understanding the intra- and extracellular proteins involved in the development of the corticospinal tract (CST) may offer insights into how the pathway could be regenerated following traumatic spinal cord injury. Currently, however, little is known about the proteome of the developing corticospinal system. The present study, therefore, has used quantitative proteomics and bioinformatics to detail the protein profile of the rat CST during its formation in the spinal cord. This analysis identified increased expression of 65 proteins during the early ingrowth of corticospinal axons into the spinal cord, and 36 proteins at the period of heightened CST growth. A majority of these proteins were involved in cellular assembly and organization, with annotations being most highly associated with cytoskeletal organization, microtubule dynamics, neurite outgrowth, and the formation, polymerization and quantity of microtubules. In addition, 22 proteins were more highly expressed within the developing CST in comparison to other developing white matter tracts of the spinal cord of age-matched animals. Of these differentially expressed proteins, only one, stathmin 1 (a protein known to be involved in microtubule dynamics), was both highly enriched in the developing CST and relatively sparse in other developing descending and ascending spinal tracts. Immunohistochemical analyses of the developing rat spinal cord and fetal human brain stem confirmed the enriched pattern of stathmin expression along the developing CST, and in vitro growth assays of rat corticospinal neurons showed a reduced length of neurite processes in response to pharmacological perturbation of stathmin activity. Combined, these findings suggest that stathmin activity may modulate axonal growth during development of the corticospinal projection, and reinforces the notion that microtubule dynamics could play an important role in the generation and regeneration of the CST.


Subject(s)
Axons/metabolism , Nerve Regeneration/physiology , Neurites/metabolism , Neurons/cytology , Pyramidal Tracts/metabolism , Stathmin/metabolism , Animals , Rats, Sprague-Dawley , Spinal Cord Injuries/metabolism
12.
ACS Appl Mater Interfaces ; 7(13): 7066-72, 2015 Apr 08.
Article in English | MEDLINE | ID: mdl-25804889

ABSTRACT

Nitrogen-doped crumpled graphene (NCG) is successfully synthesized via vapor phase deposition of polypyrrole onto graphene aerogel followed by thermal treatment. The NCG was explored as an electrocatalyst for the oxygen reduction reaction, showing comparable electrocatalytic performance with the commercial Pt/C in alkaline membrane exchange fuel cells because of the well-regulated nitrogen doping and the robust micro-3D crumpled porous nanostructure.

13.
Bioresour Technol ; 156: 84-91, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24491292

ABSTRACT

The relationship between the diversity of mixed-species microbial consortia and their electrogenic potential in the anodes of microbial fuel cells was examined using different diversity measures as predictors. Identical microbial fuel cells were sampled at multiple time-points. Biofilm and suspension communities were analysed by denaturing gradient gel electrophoresis to calculate the number and relative abundance of species. Shannon and Simpson indices and richness were examined for association with power using bivariate and multiple linear regression, with biofilm DNA as an additional variable. In simple bivariate regressions, the correlation of Shannon diversity of the biofilm and power is stronger (r=0.65, p=0.001) than between power and richness (r=0.39, p=0.076), or between power and the Simpson index (r=0.5, p=0.018). Using Shannon diversity and biofilm DNA as predictors of power, a regression model can be constructed (r=0.73, p<0.001). Ecological parameters such as the Shannon index are predictive of the electrogenic potential of microbial communities.


Subject(s)
Bacteria/growth & development , Biodiversity , Bioelectric Energy Sources , Electricity , Biofilms , DNA, Bacterial/metabolism , Electrodes , Linear Models , Multivariate Analysis
14.
Chem Commun (Camb) ; 50(1): 94-6, 2014 Jan 04.
Article in English | MEDLINE | ID: mdl-24185735

ABSTRACT

Mediator-less, direct electro-catalytic reduction of oxygen to water by bilirubin oxidase (Myrothecium sp.) was obtained on anthracene-modified, multi-walled carbon nanotubes. H2O2 was found to significantly and irreversibly affect the electro-catalytic activity of bilirubin oxidase, whereas similar electrodes comprised of laccase (Trametes versicolor) were reversibly inhibited.


Subject(s)
Biocatalysis , Electrochemistry/methods , Hydrogen Peroxide/pharmacology , Oxidoreductases Acting on CH-CH Group Donors/metabolism , Electrochemistry/instrumentation , Electrodes , Fungi, Unclassified/enzymology
15.
ACS Appl Mater Interfaces ; 5(23): 12708-15, 2013 Dec 11.
Article in English | MEDLINE | ID: mdl-24199836

ABSTRACT

Palladium-nickel (PdNi) hollow nanoparticles were synthesized via a modified galvanic replacement method using Ni nanoparticles as sacrificial templates in an aqueous medium. X-ray diffraction and transmission electron microscopy show that the as-synthesized nanoparticles are alloyed nanostructures and have hollow interiors with an average particle size of 30 nm and shell thickness of 5 nm. Compared with the commercially available Pt/C or Pd/C catalysts, the synthesized PdNi/C has superior electrocatalytic performance towards the oxygen reduction reaction, which makes it a promising electrocatalyst for alkaline anion exchange membrane fuel cells and alkali-based air-batteries. The electrocatalyst is finally examined in a H2/O2 alkaline anion exchange membrane fuel cell; the results show that such electrocatalysts could work in a real fuel cell application as a more efficient catalyst than state-of-the-art commercially available Pt/C.

16.
Phys Chem Chem Phys ; 15(44): 19371-9, 2013 Nov 28.
Article in English | MEDLINE | ID: mdl-24121716

ABSTRACT

Hydrogen peroxide production by glucose oxidase (GOx) and its negative effect on laccase performance have been studied. Simultaneously, FAD-dependent glucose dehydrogenase (FAD-GDH), an O2-insensitive enzyme, has been evaluated as a substitute. Experiments focused on determining the effect of the side reaction of GOx between its natural electron acceptor O2 (consumed) and hydrogen peroxide (produced) in the electrolyte. Firstly, oxygen consumption was investigated by both GOx and FAD-GDH in the presence of substrate. Relatively high electrocatalytic currents were obtained with both enzymes. O2 consumption was observed with immobilized GOx only, whilst O2 concentration remained stable for the FAD-GDH. Dissolved oxygen depletion effects on laccase electrode performances were investigated with both an oxidizing and a reducing electrode immersed in a single compartment. In the presence of glucose, dramatic decreases in cathodic currents were recorded when laccase electrodes were combined with a GOx-based electrode only. Furthermore, it appeared that the major loss of performance of the cathode was due to the increase of H2O2 concentration in the bulk solution induced laccase inhibition. 24 h stability experiments suggest that the use of O2-insensitive FAD-GDH as to obviate in situ peroxide production by GOx is effective. Open-circuit potentials of 0.66 ± 0.03 V and power densities of 122.2 ± 5.8 µW cm(-2) were observed for FAD-GDH/laccase biofuel cells.


Subject(s)
Bioelectric Energy Sources , Glucose 1-Dehydrogenase/metabolism , Glucose Oxidase/metabolism , Hydrogen Peroxide/metabolism , Laccase/metabolism , Biocatalysis , Electrochemical Techniques , Electrodes , Flavin-Adenine Dinucleotide/chemistry , Flavin-Adenine Dinucleotide/metabolism , Glucose/metabolism , Hydrogen Peroxide/chemistry , Oxidation-Reduction , Oxygen/chemistry , Oxygen/metabolism
17.
Phys Chem Chem Phys ; 15(10): 3518-26, 2013 Mar 14.
Article in English | MEDLINE | ID: mdl-23377101

ABSTRACT

Birnessite nanotubes and activated carbon electrodes have been used in supercapacitor cells to assess the performance of new aqueous based electrolyte systems at temperatures as low as -30 °C. The addition of ethylene glycol to aqueous sodium, lithium, potassium and ammonium sulfates has resulted in electrolytes that are still in liquid phase at such low temperatures. Extensive electrochemical testing showed that in such systems, operation of these aqueous based supercapacitors is possible at -30 °C with a specific capacitance of over 30 F g(-1) and good cycleability.

18.
Phys Chem Chem Phys ; 14(27): 9582-5, 2012 Jul 21.
Article in English | MEDLINE | ID: mdl-22678544

ABSTRACT

A glucose oxidase (GOd) bioelectrode exhibiting high performance, direct electron transfer (DET) has been prepared. Unprecedented redox peak current densities of 1 mA cm(-2) were observed alongside a clear electrochemical response to glucose. This system shows potential as a low cost, high performance enzymatic bioelectrode.


Subject(s)
Glucose Oxidase/metabolism , Cellulose/chemistry , Electrochemical Techniques , Electrodes , Electron Transport , Enzymes, Immobilized/chemistry , Enzymes, Immobilized/metabolism , Glucose/analysis , Glucose Oxidase/chemistry , Nanotubes, Carbon
19.
Appl Microbiol Biotechnol ; 93(1): 423-37, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21984392

ABSTRACT

The performance and dynamics of the bacterial communities in the biofilm and suspended culture in the anode chamber of sucrose-fed microbial fuel cells (MFCs) were studied by using denaturing gradient gel electrophoresis (DGGE) of PCR-amplified partial 16S rRNA genes followed by species identification by sequencing. The power density of MFCs was correlated to the relative proportions of species obtained from DGGE analysis in order to detect bacterial species or taxonomic classes with important functional role in electricity production. Although replicate MFCs showed similarity in performance, cluster analysis of DGGE profiles revealed differences in the evolution of bacterial communities between replicate MFCs. No correlation was found between the proportion trends of specific species and the enhancement of power output. However, in all MFCs, putative exoelectrogenic denitrifiers and sulphate-reducers accounted for approximately 24% of the bacterial biofilm community at the end of the study. Pareto-Lorenz evenness distribution curves extracted from the DGGE patterns obtained from time course samples indicated community structures where shifts between functionally similar species occur, as observed within the predominant fermentative bacteria. These results suggest the presence of functional redundancy within the anodic communities, a probable indication that stable MFC performance can be maintained in changing environmental conditions. The capability of bacteria to adapt to electricity generation might be present among a wide range of bacteria.


Subject(s)
Bacteria/classification , Bacteria/metabolism , Bioelectric Energy Sources/microbiology , Biota , Sucrose/metabolism , Bacteria/growth & development , Biofilms/growth & development , Cluster Analysis , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Denaturing Gradient Gel Electrophoresis , Electricity , Electrodes/microbiology , Molecular Sequence Data , Phylogeny , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
20.
Appl Microbiol Biotechnol ; 90(3): 1179-91, 2011 May.
Article in English | MEDLINE | ID: mdl-21400098

ABSTRACT

The spatiotemporal development of a bacterial community in an exoelectrogenic biofilm was investigated in sucrose-fed longitudinal tubular microbial fuel cell reactors, consisting of two serially connected modules. The proportional changes in the microbial community composition were assessed by polymerase chain reaction-denaturing gradient gel electrophoresis (DGGE) and DNA sequencing in order to relate them to the performance and stability of the bioelectrochemical system. The reproducibility of duplicated reactors, evaluated by cluster analysis and Jaccard's coefficient, shows 80-90% similarity in species composition. Biofilm development through fed-batch start-up and subsequent stable continuous operation results in a population shift from γ-Proteobacteria- and Bacteroidetes- to Firmicutes-dominated communities, with other diverse species present at much lower relative proportions. DGGE patterns were analysed by range-weighted richness (Rr) and Pareto-Lorenz evenness distribution curves to investigate the evolution of the bacterial community. The first modules shifted from dominance by species closely related to Bacteroides graminisolvens, Raoultella ornithinolytica and Klebsiella sp. BM21 at the start of continuous-mode operation to a community dominated by Paludibacter propionicigenes-, Lactococcus sp.-, Pantoea agglomerans- and Klebsiella oxytoca-related species with stable power generation (6.0 W/m(3)) at day 97. Operational strategies that consider the dynamics of the population will provide useful parameters for evaluating system performance in the practical application of microbial fuel cells.


Subject(s)
Bacteria/isolation & purification , Bioelectric Energy Sources/microbiology , Bacteria/classification , Bacteria/genetics , Bacteria/metabolism , Biofilms , DNA, Bacterial/genetics , Molecular Sequence Data , Phylogeny , RNA, Ribosomal, 16S/genetics , Sucrose/metabolism
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