Pseudomonas chloritidismutans sp. nov., a non-denitrifying chlorate-reducing bacterium

A Gram-negative, facultatively anaerobic, rod-shaped, dissimilatory chlorate-reducing bacterium, strain AW-1(T), was isolated from biomass of an anaerobic chlorate-reducing bioreactor. Phylogenetic analysis of the 16S rDNA sequence showed 100␜equence similarity to Pseudomonas stutzeri DSM 50227 and 98.6␜equence similarity to the type strain of P. stutzeri (DSM 5190(T)). The species P. stutzeri possesses a high degree of genotypic and phenotypic heterogeneity. Therefore, eight genomic groups, termed genomovars, have been proposed based upon DeltaT(m) values, which were used to evaluate the quality of the pairing within heteroduplexes formed by DNA--DNA hybridization. In this study, DNA--DNA hybridization between strain AW-1(T) and P. stutzeri strains DSM 50227 and DSM 5190(T) revealed respectively 80.5 and 56.5␜imilarity. DNA--DNA hybridization between P. stutzeri strains DSM 50227 and DSM 5190(T) revealed 48.4␜imilarity. DNA--DNA hybridization indicated that strain AW-1(T) is not related at the species level to the type strain of P. stutzeri. However, strain AW-1(T) and P. stutzeri DSM 50227 are related at the species level. The physiological and biochemical properties of strain AW-1(T) and the two P. stutzeri strains were compared. A common characteristic of P. stutzeri strains is the ability to denitrify. However, in growth experiments, strain AW-1(T) could use only chlorate or oxygen as an electron acceptor and not nitrate, perchlorate or bromate. Strain AW-1(T) is the first chlorate-reducing bacterium described that does not possess another oxyanion-reduction pathway. Cell extracts of strain AW-1(T) showed chlorate and bromate reductase activities but not nitrate reductase activity. P. stutzeri strains DSM 50227 and DSM 5190(T) could use nitrate or oxygen as an electron acceptor, but not chlorate. Chlorate reductase activity, in addition to nitrate reductase activity, was detected in cell extracts of both P. stutzeri strains. Chlorite dismutase activity was absent in extracts of both P. stutzeri strains but was present in extracts of strain AW-1(T). Based on the hybridization experiments and the physiological and biochemical data, it is proposed that strain AW-1(T) be classified as a novel species of Pseudomonas, Pseudomonas chloritidismutans sp. nov. The type strain is strain AW-1(T) (=DSM 13592(T)=ATCC BAA-443(T))

Extremofiele micro-organismen: some like it hot

Een duik nemen in de Noordzee op nieuwjaarsdag vinden we behoorlijk stoer. De Russen doen er een schepje bovenop door het begin van de winter te vieren met een duik in ijswater van nul graden. Dat valt best wel mee, zeker wanneer je dit afwisselt met een bezoek aan de sauna met een luchttemperatuur van 90 graden. Hiermee hebben we de extremen die we als mens kunnen trotseren echter wel gehad. Wat te denken van een duik in kokend water, zwemmen in een zwembad gevuld met azijn of ammonia, of kokend zwavelzuur? Wat voor ons onmogelijk is, is voor veel micro-organismen de normaalste zaak van de werel

Structural and biochemical characterisation of Archaeoglobus fulgidus esterase reveals a bound CoA molecule in the vicinity of the active site

A new carboxyl esterase, AF-Est2, from the hyperthermophilic archaeon Archaeoglobus fulgidus has been cloned, over-expressed in Escherichia coli and biochemically and structurally characterized. The enzyme has high activity towards short- to medium-chain pnitrophenyl carboxylic esters with optimal activity towards the valerate ester. The AF-Est2 has good solvent and pH stability and is very thermostable, showing no loss of activity after incubation for 30 min at 80 °C. The 1.4 Å resolution crystal structure of AF-Est2 reveals Coenzyme A (CoA) bound in the vicinity of the active site. Despite the presence of CoA bound to the AF-Est2 this enzyme has no CoA thioesterase activity. The pantetheine group of CoA partially obstructs the active site alcohol pocket suggesting that this ligand has a role in regulation of the enzyme activity. A comparison with closely related α/β hydrolase fold 2 enzyme structures shows that the AF-Est2 has unique structural features that allow CoA binding. A comparison of the structure of AF-Est2 with the human carboxyl esterase 1, which has CoA thioesterase activity, reveals that CoA is bound to different parts of the core domain in these two enzymes and approaches the active site from opposite directions.This work was supported by the Hotzyme project (grant agreement no. 265933) financed by the European Union 7th Framework Programme FP7/2007-2013. WF is funded by a BBSRC PhD studentship. MI would like to thank the BBSRC funded ERA-IB grant BB/L002035/1 and the University of Exeter for support. The authors would like to thank the Diamond Synchrotron Light Source for access to beamline I03 (proposals No. MX8889 and No. MX11945) and the beamline scientists for assistance. The work of ML was funded by the Graduate School VLAG Wageningen, the Netherlan

Forests for the New Millennium - MAKING FORESTS WORK FOR PEOPLE AND NATURE

THE WAYS IN WHICH FORESTS ARE PERCEIVED AND USED HAVE CHANGED DRAMATICALLY OVER RECENT YEARS. FORESTS ARE NO LONGER SEEN SIMPLY AS A SOURCE OF TIMBER, BUT AS COMPLEX ECOSYSTEMS WHICH SUSTAIN LIVELIHOODS AND PROVIDE A RANGE OF PRODUCTS AND ENVIRONMENTAL SERVICES. IT IS NOW WIDELY RECOGNISED THAT FORESTS CAN CONTRIBUTE TO RURAL DEVELOPMENT AND POVERTY ALLEVIATION.Forest, economics, livelihoods

Perceptions about the sexuality of women with fibromyalgia syndrome: a phenomenological study

Aims: The aim of this study was to explore and understand the perceptions and experiences of women with fibromyalgia syndrome regarding their sexuality. Background: Fibromyalgia syndrome is a chronic pathology, which compromises a woman’s physical, mental and emotional health. Although concerns related to sexuality are commonly reported, research has tended to focus on the physical symptoms. Design: An interpretive qualitative research methodology using Gadamer’s philosophical hermeneutics was carried out. Methods: This qualitative study explores the sexuality of women with fibromyalgia syndrome. A focus group and semi-structured interviews were conducted with 13 women with fibromyalgia syndrome. Data were collected between April - June 2014. Participants were recruited until findings reached saturation. Findings: Three themes define the perception of sexuality for these women: (i) Physical impact: don’t touch, don’t look; (ii) Sexuality and identity: fighting against their loss; (iii) Impact on the relationship: sexuality as a way of connecting the couple. Conclusion: Despite limitations, sexuality is important for the identity and quality of life of women with fibromyalgia syndrome. Together with the physical symptomology, guilt, fear and a lack of understanding compromise the coping process. Women need the support of their partner, their socio-family environment and health professionals. Nurses can aid the successful adjustment to sexual problems related to fibromyalgia syndrome

Genome and proteome analysis of Pseudomonas chloritidismutans AW-1T that grows on n-decane with chlorate or oxygen as electron acceptor

Growth of Pseudomonas chloritidismutans AW-1T on C7 to C12 n-alkanes with oxygen or chlorate as electron acceptor was studied by genome and proteome analysis. Whole genome shotgun sequencing resulted in a 5 Mbp assembled sequence with a G+C content of 62.5% The automatic annotation identified 4767 protein-encoding genes and a putative function could be assigned to almost 80% of the predicted proteins. The distinct phylogenetic position of P. chloritidismutans AW-1T within the Pseudomonas stutzeri cluster became clear by comparison of average nucleotide identity values of sequenced genomes. Analysis of the proteome of P. chloritidismutans AW-1T showed the versatility of this bacterium to adapt to aerobic and anaerobic growth conditions with acetate or n-decane as substrates. All enzymes involved in the alkane oxidation pathway were identified. An alkane monooxygenase was detected in n-decane-grown cells, but not in acetate-grown cells. The enzyme was found when grown in the presence of oxygen or chlorate, indicating that under both conditions an oxygenase-mediated pathway is employed for alkane degradation. Proteomic and biochemical data also showed that both chlorate reductase and chlorite dismutase are constitutively present, but most abundant under chlorate-reducing conditions.Technology Foundation STW, Applied Science Division of the Netherlands Science Foundation NWO, Chemical Sciences (CW) of NWO, the technology program Economy Ecology Technology and the Higher Education Commission of Pakistan (HEC) and the Teaching Grant of Wageningen UniversityERC grants (project 323009 and 250172) and the Gravitation grant (project 024.002.002) of the Netherlands Ministry of Education, Culture and Science and the Netherlands Science Foundation (NWO

Education Research: Virtual Patient Management Conference for Epilepsy Surgery in the Post-COVID-19 Era: An Educational Perspective

BACKGROUND AND OBJECTIVES: The primary objective of this study was to assess the potential educational value of a virtual patient management conference (PMC) with the introduction of inclusive anonymous polling at a comprehensive epilepsy center. The secondary objective was to evaluate differences between faculty and trainee polling results. METHODS: Two online surveys were sent 1 year apart seeking opinions about a transition to virtual PMC and completed by virtual PMC faculty participants (including representatives from neurology, neurosurgery, and neuropsychology). One online survey was sent to trainees (medical students, residents, and fellows) to assess the educational value of the conference. Anonymous electronic polls surveying treatment options were completed by both faculty and trainees after each virtual PMC presentation but before discussing the case. The results were collected and analyzed over 16 months, including over the course of 1 academic year. The degree of consensus was determined by the maximum percentage of votes that a single choice received. RESULTS: Eleven faculty and 22 trainees responded to their respective surveys. The initial faculty survey revealed that 60.0% of faculty had an excellent or very good experience with virtual PMC; 1 year later, this proportion increased to 100.0% while trainees reported 90.9%. Each virtual PMC component, including perceived standard of care, was found to be excellent or very good by most faculty and trainees, and most (91% faculty, 63.7% trainees) were equally comfortable or more comfortable expressing opinions during the virtual discussion. During virtual PMC polls, faculty members were significantly more likely to vote for vagus nerve stimulation as a treatment option, while trainees were more likely to opt for responsive neurostimulation. Linear regression over the course of the academic year showed stable consensus over time for both faculty and trainees; however, the match between faculty and trainee consensus significantly increased over the academic year. DISCUSSION: Our results demonstrate that the virtual PMC constitutes an effective educational experience as an alternative to in-person conferences for the management of patients with drug-resistant epilepsy

Optical angle and visuospatial ability affect basic laparoscopic simulator task performance

Surgical trainees show decreased performance during laparoscopic surgery when the laparoscope (camera) is not aligned with their line of sight towards the operating area. In this study we investigate the influence of visuospatial ability on laparoscopic simulator performance under such non-zero optical angles. Novices were invited to participate in a laparoscopic training session. After completing a visuospatial ability assessment, they performed a simplified laparoscopic task on an in-house developed laparoscopic simulator under eight different optical angles ranging between 0° and 315° in steps of 45°. Data-analysis showed decreased performance under all non-zero optical angles for task duration (mean difference between 1506 and 5049 ms, standard error between 499 and 507, p &lt; .05) and for accuracy under optical angles greater than ±45° (mean difference between 1.48 and 2.11, standard error 0.32, p &lt; .01). Performance-zones were identified for various optical angle ranges and differed for task duration and accuracy. Participants of high visuospatial ability performed significantly better under non-zero angles for accuracy compared to participants of low visuospatial ability (mean difference 0.95, standard error 0.34, p &lt; .01), except for the 180° optical angle (no difference).</p