bluuebunny/crossref_metadata_2025 huggingface dataset:
Long‐term musculoskeletal and cardiac health effects of recreational football and running for premenopausal women
Authors: Krustrup P. , Hansen P. R. , Andersen L. J. , Jakobsen M. D. , Sundstrup E. , Randers M. B. , Christiansen L. , Helge E. W. , Pedersen M. T. , Søgaard P. , Junge A. , Dvorak J. , Aagaard P. , Bangsbo J.
Published: May 2010

We examined long‐term musculoskeletal and cardiac adaptations elicited by recreational football (FG, n=9) and running (RG, n=10) in untrained premenopausal women in comparison with a control group (CG, n=9). Training was performed for 16 months (∼2 weekly 1‐h sessions). For FG, right and left ventricular end‐diastolic diameters were increased by 24% and 5% (P<0.05), respectively, after 16 months. Right ventricular systolic function measured by tricuspid annular plane systolic excursion (TAPSE) increased (P<0.05) in FG after 4 months and further (P<0.05) after 16 months (15% and 32%, respectively). In RG and CG, cardiac structure, E/A and TAPSE remained unchanged. For FG, whole‐body bone mineral density (BMD) was 2.3% and 1.3% higher (P<0.05) after 16 months, than after 4 and 0 months, respectively, with no changes for RG and CG. FG demonstrated substantial improvements (P<0.05) in fast (27% and 16%) and slow (16% and 17%) eccentric muscle strength and rapid force capacity (Imp30ms: 66% and 65%) after 16 months compared with 4 and 0 months, with RG improving Imp30ms by 64% and 46%. In conclusion, long‐term recreational football improved muscle function, postural balance and BMD in adult women with a potential favorable influence on the risk of falls and fractures. Moreover, football training induced consistent cardiac adaptations, which may have implications for long‐term cardiovascular health.
A novel Chlamydiaceae‐like bacterium found in faecal specimens from sea birds from the Bering Sea
Authors: Christerson Linus , Blomqvist Maria , Grannas Karin , Thollesson Mikael , Laroucau Karine , Waldenström Jonas , Eliasson Ingvar , Olsen Björn , Herrmann Björn
Published: May 2010

The family Chlamydiaceae contains several bacterial pathogens of important human and veterinary medical concern, such as Chlamydia trachomatis and Chlamydophila psittaci. Within the order Chlamydiales there are also an increasing number of chlamydia‐like bacteria whose biodiversity, host range and environmental spread seem to have been largely underestimated, and which are currently being investigated for their potential medical relevance. In this study we present 16S rRNA, rnpB and ompA gene sequence data congruently indicating a novel chlamydia‐like bacterium found in faecal specimens from opportunistic fish‐eating sea birds, belonging to the Laridae and Alcidae families, from the Bering Sea. This novel bacterium appears to be closer to the Chlamydiaceae than other chlamydia‐like bacteria and is most likely a novel genus within the Chlamydiaceae family.
Sovereign Wealth Funds: An Assessment
Authors: Bahgat Gawdat
Published: May 2010

High oil prices and impressive economic performance in emerging markets have led to the accumulation of massive financial assets. These nations have created sovereign wealth funds (SWFs) to manage their growing assets. SWFs have provided significant liquidity to American and European financial institutions. The rise of SWFs in number and size has raised concern about their objectives and strategies. This study examines the role these state‐owned funds play in the global markets and the efforts to regulate their activities. I argue that capital exporting and importing nations share common interests and reciprocal responsibility in ensuring global financial prosperity.

Policy Implications

Sovereign wealth funds are currently important players in the international financial system and are projected to become even more influential in the future.

Sovereign wealth funds investments are driven more by commercial interests and less by political objectives.

The interests of capital exporting and capital importing nations are not mutually exclusive. Rather, both seek economic prosperity and political stability.

Too much regulation of sovereign wealth funds’ activities is likely to weaken cross‐border trade and investment.

Sovereign wealth funds should gain the confidence of host countries by accepting a high level of transparency.
Cyclooxygenase-2 Controls Energy Homeostasis in Mice by de Novo Recruitment of Brown Adipocytes
Authors: Vegiopoulos Alexandros , Müller-Decker Karin , Strzoda Daniela , Schmitt Iris , Chichelnitskiy Evgeny , Ostertag Anke , Diaz Mauricio Berriel , Rozman Jan , Hrabe de Angelis Martin , Nüsing Rolf M. , Meyer Carola W. , Wahli Walter , Klingenspor Martin , Herzig Stephan
Published: May 2010

Fat-Burning Fat

In mammals, fat exists in two forms—the well-known white adipose tissue (WAT), which stores energy and is associated with obesity, and the lesser-known brown adipose tissue (BAT), which burns energy to generate heat. BAT's role in human physiology was once thought to be restricted to newborns, but the recent discovery that adults also harbor functional BAT has re-ignited interest in the factors regulating BAT development and their potential as targets for anti-obesity therapies.

Vegiopoulos
et al.

(p.
1158
, published online 6 May; see the Perspective

Ishibashi and Seale

) now show that cyclooxygenase-2 (COX-2), an enzyme critical to prostaglandin synthesis, triggers fat progenitor cells in mice to differentiate into BAT rather than WAT. Mice overexpressing COX-2 displayed increased energy expenditure and were protected from diet-induced obesity.
Disruption of the Putative Cell Surface Polysaccharide Biosynthesis Gene SO3177 in
Shewanella oneidensis
MR-1 Enhances Adhesion to Electrodes and Current Generation in Microbial Fuel Cells
Authors: Kouzuma Atsushi , Meng Xian-Ying , Kimura Nobutada , Hashimoto Kazuhito , Watanabe Kazuya
Published: May 2010

A microbial fuel cell (MFC) was inoculated with a random transposon insertion mutant library of
Shewanella oneidensis
MR-1 and operated with lactate as the sole fuel to select for mutants that preferentially grew in it. Agar plate cultivation of the resultant MFC enrichment culture detected an increased number of colonies exhibiting rough morphology. One such isolate, strain 4A, generated 50% more current in an MFC than wild-type MR-1. Determination of the transposon insertion site in strain 4A followed by deletion and complementation experiments revealed that the SO3177 gene, encoding a putative formyltransferase and situated in a cell surface polysaccharide biosynthesis gene cluster, was responsible for the increased current. Transmission electron microscopy showed that a layered structure at the cell surface, stainable with ruthenium red, was impaired in the SO3177 mutant (ΔSO3177), confirming that SO3177 is involved in the biosynthesis of cell surface polysaccharides. Compared to the wild type, ΔSO3177 cells preferentially attached to graphite felt anodes in MFCs, while physicochemical analyses revealed that the cell surface of ΔSO3177 was more hydrophobic. These results demonstrate that cell surface polysaccharides affect not only the cell adhesion to graphite anodes but also the current generation in MFCs.
Hydrogen Production by the Unicellular, Diazotrophic Cyanobacterium
Cyanothece
sp. Strain ATCC 51142 under Conditions of Continuous Light
Authors: Min Hongtao , Sherman Louis A.
Published: May 2010

We report on the hydrogen production properties of the unicellular, diazotrophic cyanobacterium
Cyanothece
sp. strain ATCC 51142. This organism has a versatile metabolism and can grow in the presence or absence of combined nitrogen and can grow photosynthetically or mixotrophically and heterotrophically in the presence of glycerol. The strain produces a bidirectional hydrogenase (encoded by the
hox
genes), an uptake hydrogenase (
hupLS
), and nitrogenase (
nifHDK
). We demonstrated hydrogen production by both the hydrogenase and the nitrogenase under appropriate metabolic conditions. The highest rates of hydrogen production were produced under nitrogen-fixing conditions when cells were grown and incubated under continuous light conditions, in either the presence or absence of glycerol. Under such nitrogen-fixing conditions, we have achieved rates of 300 μmol H
2
/mg chloramphenicol (Chl)/hr during the first 24 h of incubation. The levels of H
2
measured were dependent upon the incubation conditions, such as sparging with argon, which generated anaerobic conditions. We demonstrated that the same conditions led to high levels of H
2
production and N
2
fixation, indicating that low-oxygen conditions favor nitrogenase activity for both processes. The levels of hydrogen produced by the hydrogenase are much lower, typically 5 to 10 μmol H
2
/mg Chl/hr. Hydrogenase activity was dependent upon electron transport through photosystem II (PS II), whereas nitrogenase activity was more dependent on PS I, as well as on respiration. Although cells do not double under the incubation conditions when sparged with argon to provide a low-oxygen environment, the cells are metabolically active, and hydrogen production can be inhibited by the addition of chloramphenicol to inhibit protein synthesis.
Dual Reporter System for
In Situ
Detection of Plasmid Transfer under Aerobic and Anaerobic Conditions
Authors: Król Jaroslaw E. , Rogers Linda M. , Krone Stephen M. , Top Eva M.
Published: May 2010

We designed a new genetic tool to detect plasmid transfer under anaerobic and aerobic conditions. The system is based on the T7 RNA polymerase gene and a T7 promoter-driven oxygen-independent green fluorescent protein, evoglow, alone or in combination with red fluorescent protein DsRed. Constructs are available as plasmids and mini-
mariner
transposons.
High-Throughput Procedure for Tick Surveys of Tick-Borne Encephalitis Virus and Its Application in a National Surveillance Study in Switzerland
Authors: Gäumann Rahel , Mühlemann Kathrin , Strasser Marc , Beuret Christian M.
Published: May 2010

Tick-borne encephalitis (TBE), a viral infection of the central nervous system, is endemic in many Eurasian countries. In Switzerland, TBE risk areas have been characterized by geographic mapping of clinical cases. Since mass vaccination should significantly decrease the number of TBE cases, alternative methods for exposure risk assessment are required. We established a new PCR-based test for the detection of TBE virus (TBEV) in ticks. The protocol involves an automated, high-throughput nucleic acid extraction method (QIAsymphony SP system) and a one-step duplex real-time reverse transcription-PCR (RT-PCR) assay for the detection of European subtype TBEV, including an internal process control. High usability, reproducibility, and equivalent performance for virus concentrations down to 5 × 10
3
viral genome equivalents/μl favor the automated protocol compared to the modified guanidinium thiocyanate-phenol-chloroform extraction procedure. The real-time RT-PCR allows fast, sensitive (limit of detection, 10 RNA copies/μl), and specific (no false-positive test results for other TBEV subtypes, other flaviviruses, or other tick-transmitted pathogens) detection of European subtype TBEV. The new detection method was applied in a national surveillance study, in which 62,343
Ixodes ricinus
ticks were screened for the presence of TBE virus. A total of 38 foci of endemicity could be identified, with a mean virus prevalence of 0.46%. The foci do not fully agree with those defined by disease mapping. Therefore, the proposed molecular test procedure constitutes a prerequisite for an appropriate TBE surveillance. Our data are a unique complement of human TBE disease case mapping in Switzerland.
Disruption of the Glycine Cleavage System Enables
Sinorhizobium fredii
USDA257 To Form Nitrogen-Fixing Nodules on Agronomically Improved North American Soybean Cultivars
Authors: Lorio Julio C. , Kim Won-Seok , Krishnan Ammulu H. , Krishnan Hari B.
Published: May 2010

The symbiosis between
Sinorhizobium fredii
USDA257 and soybean [
Glycine max
(L.) Merr.] exhibits a high degree of cultivar specificity. USDA257 nodulates primitive soybean cultivars but fails to nodulate agronomically improved cultivars such as McCall. In this study we provide evidence for the involvement of a new genetic locus that controls soybean cultivar specificity. This locus was identified in USDA257 by Tn
5
transposon mutagenesis followed by nodulation screening on McCall soybean. We have cloned the region corresponding to the site of Tn
5
insertion and found that it lies within a 1.5-kb EcoRI fragment. DNA sequence analysis of this fragment and an adjacent 4.4-kb region identified an operon made up of three open reading frames encoding proteins of deduced molecular masses of 41, 13, and 104 kDa, respectively. These proteins revealed significant amino acid homology to glycine cleavage (
gcv
) system T, H, and P proteins of
Escherichia coli
and other organisms. Southern blot analysis revealed the presence of similar sequences in diverse rhizobia. Measurement of β-galactosidase activity of a USDA257 strain containing a transcriptional fusion of gcv
T
promoter sequences to the
lacZ
gene revealed that the USDA257
gcvTHP
operon was inducible by glycine. Inactivation of either
gcvT
or
gcvP
of USDA257 enabled the mutant to nodulate several agronomically improved North American soybean cultivars. These nodules revealed anatomical features typical of determinate nodules, with numerous bacteroids within the infected cells. Unlike for the previously characterized soybean cultivar specificity locus
nolBTUVW
, inactivation of the
gcv
locus had no discernible effect on the secretion of nodulation outer proteins of USDA257.
Shotgun Proteomics of
Aspergillus niger
Microsomes upon
d
-Xylose Induction
Authors: de Oliveira José Miguel P. Ferreira , van Passel Mark W. J. , Schaap Peter J. , de Graaff Leo H.
Published: May 2010

Protein secretion plays an eminent role in cell maintenance and adaptation to the extracellular environment of microorganisms. Although protein secretion is an extremely efficient process in filamentous fungi, the mechanisms underlying protein secretion have remained largely uncharacterized in these organisms. In this study, we analyzed the effects of the
d
-xylose induction of cellulase and hemicellulase enzyme secretion on the protein composition of secretory organelles in
Aspergillus niger
. We aimed to systematically identify the components involved in the secretion of these enzymes via mass spectrometry of enriched subcellular microsomal fractions. Under each condition, fractions enriched for secretory organelles were processed for tandem mass spectrometry, resulting in the identification of peptides that originate from 1,081 proteins, 254 of which—many of them hypothetical proteins—were predicted to play direct roles in the secretory pathway.
d
-Xylose induction led to an increase in specific small GTPases known to be associated with polarized growth, exocytosis, and endocytosis. Moreover, the endoplasmic-reticulum-associated degradation (ERAD) components Cdc48 and all 14 of the 20S proteasomal subunits were recruited to the secretory organelles. In conclusion, induction of extracellular enzymes results in specific changes in the secretory subproteome of
A. niger
, and the most prominent change found in this study was the recruitment of the 20S proteasomal subunits to the secretory organelles.
Ecological Factors Characterizing the Prevalence of Bacterial Tick-Borne Pathogens in
Ixodes ricinus
Ticks in Pastures and Woodlands
Authors: Halos Lénaïg , Bord Séverine , Cotté Violaine , Gasqui Patrick , Abrial David , Barnouin Jacques , Boulouis Henri-Jean , Vayssier-Taussat Muriel , Vourc'h Gwenaël
Published: May 2010

Ecological changes are recognized as an important driver behind the emergence of infectious diseases. The prevalence of infection in ticks depends upon ecological factors that are rarely taken into account simultaneously. Our objective was to investigate the influences of forest fragmentation, vegetation, adult tick hosts, and habitat on the infection prevalence of three tick-borne bacteria,
Borrelia burgdorferi
sensu lato,
Anaplasma phagocytophilum
, and
Rickettsia
sp. of the spotted fever group, in questing
Ixodes ricinus
ticks, taking into account tick characteristics. Samples of questing nymphs and adults were taken from 61 pastures and neighboring woodlands in central France. The ticks were tested by PCR of pools of nymphs and individual adults. The individual infection prevalence was modeled using multivariate regression. The highest infection prevalences were found in adult females collected in woodland sites for
B. burgdorferi
sensu lato and
A. phagocytophilum
(16.1% and 10.7%, respectively) and in pasture sites for
Rickettsia
sp. (8.7%). The infection prevalence in nymphs was lower than 6%.
B. burgdorferi
sensu lato was more prevalent in woodlands than in pastures. Forest fragmentation favored
B. burgdorferi
sensu lato and
A. phagocytophilum
prevalence in woodlands, and in pastures, the
B. burgdorferi
sensu lato prevalence was favored by shrubby vegetation. Both results are probably because large amounts of edges or shrubs increase the abundance of small vertebrates as reservoir hosts. The
Rickettsia
sp. prevalence was maximal on pasture with medium forest fragmentation. Female ticks were more infected by
B. burgdorferi
sensu lato than males and nymphs in woodland sites, which suggests an interaction between the ticks and the bacteria. This study confirms the complexity of the tick-borne pathogen ecology. The findings support the importance of small vertebrates as reservoir hosts and make a case for further studies in Europe on the link between the composition of the reservoir host community and the infection prevalence in ticks.
Phylogenetic Position and Peculiar Genetic Traits of a Midgut Bacterial Symbiont of the Stinkbug
Parastrachia japonensis
Authors: Hosokawa Takahiro , Kikuchi Yoshitomo , Nikoh Naruo , Meng Xian-Ying , Hironaka Mantaro , Fukatsu Takema
Published: May 2010

The stinkbug
Parastrachia japonensis
(Hemiptera: Parastrachiidae) is known for its prolonged prereproductive nonfeeding period, maternal care of eggs in an underground nest, and maternal collection and provisioning of food (fruits) for nymphs. A previous study suggested that a bacterial symbiont is involved in uric acid recycling in this insect during the nonfeeding period, but the identity of this symbiont has not been determined. Here we characterized a novel bacterial symbiont obtained from
P. japonensis
. Molecular phylogenetic analyses based on 16S rRNA,
gyrB
, and
groEL
gene sequences consistently indicated that this symbiont constituted a distinct lineage in the
Gammaproteobacteria
that has no close relatives but is allied with gut symbionts of acanthosomatid and plataspid stinkbugs, as well as with endocellular symbionts of sharpshooters, tsetse flies, and aphids. The symbiont genes had a remarkably AT-biased nucleotide composition and exhibited significantly accelerated molecular evolution. The symbiont genome was extremely reduced; its size was estimated to be 0.85 Mb. These results suggest that there has been an intimate host-symbiont association over evolutionary time. The symbiont was localized in swollen crypts in a posterior part of the midgut, which was a specialized symbiotic organ. The possibility that the symbiont is involved in uric acid recycling is discussed. The designation “
Candidatus
Benitsuchiphilus tojoi” is proposed for the symbiont.
Increase in Acid Tolerance of
Campylobacter jejuni
through Coincubation with Amoebae
Authors: Axelsson-Olsson Diana , Svensson Lovisa , Olofsson Jenny , Salomon Paulo , Waldenström Jonas , Ellström Patrik , Olsen Björn
Published: May 2010

Campylobacter jejuni
is a recognized and common gastrointestinal pathogen in most parts of the world. Human infections are often food borne, and the bacterium is frequent among poultry and other food animals. However, much less is known about the epidemiology of
C. jejuni
in the environment and what mechanisms the bacterium depends on to tolerate low pH. The sensitive nature of
C. jejuni
stands in contrast to the fact that it is difficult to eradicate from poultry production, and even more contradictory is the fact that the bacterium is able to survive the acidic passage through the human stomach. Here we expand the knowledge on
C. jejuni
acid tolerance by looking at protozoa as a potential epidemiological pathway of infection. Our results showed that when
C. jejuni
cells were coincubated with
Acanthamoeba polyphaga
in acidified phosphate-buffered saline (PBS) or tap water, the bacteria could tolerate pHs far below those in their normal range, even surviving at pH 4 for 20 h and at pH 2 for 5 h. Interestingly, moderately acidic conditions (pH 4 and 5) were shown to trigger
C. jejuni
motility as well as to increase adhesion/internalization of bacteria into
A. polyphaga
. Taken together, the results suggest that protozoa may act as protective hosts against harsh conditions and might be a potential risk factor for
C. jejuni
infections. These findings may be important for our understanding of
C. jejuni
passage through the gastrointestinal tract and for hygiene practices used in poultry settings.
Assessing the Potential of an Induced-Mutation Strategy for Avermectin Overproducers
Authors: Gao Hong , Liu Mei , Zhuo Ying , Zhou Xianlong , Liu Jintao , Chen Difei , Zhang Wenquan , Gou Zhongxuan , Shang Peng , Zhang Lixin
Published: May 2010

Mutant libraries of avermectin-producing
Streptomyces avermitilis
strains were constructed by different mutagenesis strategies. A metric was applied to assess the mutation spectrum by calculating the distribution of average phenotypic distance of each population. The results showed for the first time that a microgravity environment could introduce larger phenotype distribution and diversity than UV and
N
-methyl-
N
-nitro-
N
-nitrosoguanidine (NTG) could.
Metagenomic Analysis of Apple Orchard Soil Reveals Antibiotic Resistance Genes Encoding Predicted Bifunctional Proteins
Authors: Donato Justin J. , Moe Luke A. , Converse Brandon J. , Smart Keith D. , Berklein Flora C. , McManus Patricia S. , Handelsman Jo
Published: May 2010

To gain insight into the diversity and origins of antibiotic resistance genes, we identified resistance genes in the soil in an apple orchard using functional metagenomics, which involves inserting large fragments of foreign DNA into
Escherichia coli
and assaying the resulting clones for expressed functions. Among 13 antibiotic-resistant clones, we found two genes that encode bifunctional proteins. One predicted bifunctional protein confers resistance to ceftazidime and contains a natural fusion between a predicted transcriptional regulator and a β-lactamase. Sequence analysis of the entire metagenomic clone encoding the predicted bifunctional β-lactamase revealed a gene potentially involved in chloramphenicol resistance as well as a predicted transposase. A second clone that encodes a predicted bifunctional protein confers resistance to kanamycin and contains an aminoglycoside acetyltransferase domain fused to a second acetyltransferase domain that, based on nucleotide sequence, was predicted not to be involved in antibiotic resistance. This is the first report of a transcriptional regulator fused to a β-lactamase and of an aminoglycoside acetyltransferase fused to an acetyltransferase not involved in antibiotic resistance.
Comparison of Different DNA-Based Methods for Molecular Typing of
Histoplasma capsulatum
Authors: Muniz Mauro de Medeiros , Morais e Silva Tavares Patrícia , Meyer Wieland , Nosanchuk Joshua Daniel , Zancope-Oliveira Rosely Maria
Published: May 2010

Histoplasma capsulatum
is very prevalent in the environment and is one of the most common causes of mycoses in humans and diverse animals in Brazil. Multiple typing methods have been developed to study
H. capsulatum
epidemiology; however, there is limited information concerning comparisons of results obtained with different methods using the same set of isolates. To explore the diversity of
H. capsulatum
in Brazil and to determine correlations between the results of three different molecular typing techniques, we examined 51 environmental, animal, and human isolates by M13 PCR fingerprinting, PCR-restriction fragment length polymorphism (RFLP) analysis of the internal transcribed region 1 (ITS1)-5.8S-ITS2 region of the rDNA locus, and DNA sequencing and phylogenetic analysis of parts of four protein-encoding genes, the
Arf
(ADP ribosylation factor), H-anti (H antigen precursor),
Ole
(delta-9 fatty acid desaturase), and
Tub1
(alpha-tubulin) genes. Each method identified three major genetic clusters, and there was a high level of concordance between the results of the typing techniques. The M13 PCR fingerprinting and PCR-RFLP analyses produced very similar results and separated the
H. capsulatum
isolates included in this study into three major groups. An additional approach used was comparison of our Brazilian ITS1-5.8S-ITS2 sequences with the sequences deposited previously in NCBI data banks. Our analyses suggest that
H. capsulatum
can be divided into different molecular types that are dispersed around the world. Our results indicate that the three methods used in this study are reliable and reproducible and that they have similar sensitivities. However, M13 PCR fingerprinting has some advantages over the other two methods as it is faster, cheaper, and more user friendly, which especially increases its utility for molecular typing of
Histoplasma
in situations where laboratory facilities are relatively limited.
Improvement of Multiple-Stress Tolerance and Lactic Acid Production inLactococcus lactisNZ9000 under Conditions of Thermal Stress by Heterologous Expression ofEscherichia coli dnaK
Authors: Abdullah-Al-Mahin  , Sugimoto Shinya , Higashi Chihana , Matsumoto Shunsuke , Sonomoto Kenji
Published: May 2010

The effects of nisin-induceddnaKexpression inLactococcus lactiswere examined, and this expression was shown to improve stress tolerance and lactic acid fermentation efficiency. Using a nisin-inducible expression system, DnaK proteins fromL. lactis(DnaKLla) andEscherichia coli(DnaKEco) were produced inL. lactisNZ9000. In comparison to a strain harboring the empty vector pNZ8048 (designated NZ-Vector) and one expressingdnaKLla(designated NZ-LDnaK), thednaKEco-expressing strain, named NZ-EDnaK, exhibited more tolerance to heat stress at 40°C in GM17 liquid medium. The cell viability of NZ-Vector was reduced 4.6-fold after 6 h of heat treatment. However, NZ-EDnaK showed 13.5-fold increased viability under these conditions, with a very low concentration of DnaKEcoproduction. Although the heterologous expression ofdnaKEcodid not effect DnaKLlaproduction, heat treatment increased the DnaKLlalevel 3.5- and 3.6-fold in NZ-Vector and NZ-EDnaK, respectively. Moreover, NZ-EDnaK showed tolerance to multiple stresses, including 3% NaCl, 5% ethanol, and 0.5% lactic acid (pH 5.47). In CMG medium, the lactate yield and the maximum lactate productivity of NZ-EDnaK were higher than the corresponding values for NZ-Vector at 30°C. Interestingly, at 40°C, these values of NZ-EDnaK were not significantly different from the corresponding values for the control strain at 30°C. Lactate dehydrogenase (LDH) activity was also found to be stable at 40°C in the presence of DnaKEco. These findings suggest that the heterologous expression ofdnaKEcoenhances the quality control of proteins and enzymes, resulting in improved growth and lactic acid fermentation at high temperature.
Evaluation of a Stochastic Inactivation Model for Heat-Activated Spores of
Bacillus
spp
Authors: Corradini Maria G. , Normand Mark D. , Eisenberg Murray , Peleg Micha
Published: May 2010

Heat activates the dormant spores of certain
Bacillus
spp., which is reflected in the “activation shoulder” in their survival curves. At the same time, heat also inactivates the already active and just activated spores, as well as those still dormant. A stochastic model based on progressively changing probabilities of activation and inactivation can describe this phenomenon. The model is presented in a fully probabilistic discrete form for individual and small groups of spores and as a semicontinuous deterministic model for large spore populations. The same underlying algorithm applies to both isothermal and dynamic heat treatments. Its construction does not require the assumption of the activation and inactivation kinetics or knowledge of their biophysical and biochemical mechanisms. A simplified version of the semicontinuous model was used to simulate survival curves with the activation shoulder that are reminiscent of experimental curves reported in the literature. The model is not intended to replace current models to predict dynamic inactivation but only to offer a conceptual alternative to their interpretation. Nevertheless, by linking the survival curve's shape to probabilities of events at the individual spore level, the model explains, and can be used to simulate, the irregular activation and survival patterns of individual and small groups of spores, which might be involved in food poisoning and spoilage.
Microbial Community Structure and Denitrification in a Wetland Mitigation Bank
Authors: Peralta Ariane L. , Matthews Jeffrey W. , Kent Angela D.
Published: May 2010

Wetland mitigation is implemented to replace ecosystem functions provided by wetlands; however, restoration efforts frequently fail to establish equivalent levels of ecosystem services. Delivery of microbially mediated ecosystem functions, such as denitrification, is influenced by both the structure and activity of the microbial community. The objective of this study was to compare the relationship between soil and vegetation factors and microbial community structure and function in restored and reference wetlands within a mitigation bank. Microbial community composition was assessed using terminal restriction fragment length polymorphism targeting the 16S rRNA gene (total bacteria) and the
nosZ
gene (denitrifiers). Comparisons of microbial function were based on potential denitrification rates. Bacterial community structures differed significantly between restored and reference wetlands; denitrifier community assemblages were similar among reference sites but highly variable among restored sites throughout the mitigation bank. Potential denitrification was highest in the reference wetland sites. These data demonstrate that wetland restoration efforts in this mitigation bank have not successfully restored denitrification and that differences in potential denitrification rates may be due to distinct microbial assemblages observed in restored and reference (natural) wetlands. Further, we have identified gradients in soil moisture and soil fertility that were associated with differences in microbial community structure. Microbial function was influenced by bacterial community composition and soil fertility. Identifying soil factors that are primary ecological drivers of soil bacterial communities, especially denitrifying populations, can potentially aid the development of predictive models for restoration of biogeochemical transformations and enhance the success of wetland restoration efforts.
Population Structure and Abundance of Arsenite-Oxidizing Bacteria along an Arsenic Pollution Gradient in Waters of the Upper Isle River Basin, France
Authors: Quéméneur Marianne , Cébron Aurélie , Billard Patrick , Battaglia-Brunet Fabienne , Garrido Francis , Leyval Corinne , Joulian Catherine
Published: May 2010

Denaturing gradient gel electrophoresis (DGGE) and quantitative real-time PCR (qPCR) were successfully developed to monitor functional
aoxB
genes as markers of aerobic arsenite oxidizers. DGGE profiles showed a shift in the structure of the
aoxB
-carrying bacterial population, composed of members of the
Alpha
-,
Beta
- and
Gammaproteobacteria
, depending on arsenic (As) and E
h
levels in Upper Isle River Basin waters. The highest
aoxB
gene densities were found in the most As-polluted oxic surface waters but without any significant correlation with environmental factors. Arsenite oxidizers seem to play a key role in As mobility in As-impacted waters.
Regrowth of Potential Opportunistic Pathogens and Algae in Reclaimed-Water Distribution Systems
Authors: Jjemba Patrick K. , Weinrich Lauren A. , Cheng Wei , Giraldo Eugenio , LeChevallier Mark W.
Published: May 2010

A study of the quality of reclaimed water in treated effluent, after storage, and at three points in the distribution system of four plants in California, Florida, Massachusetts, and New York was conducted for 1 year. The plants had different treatment processes (conventional versus membrane bioreactor), production capacities, and methods for storage of the water, and the intended end uses of the water were different. The analysis focused on the occurrence of indicator bacteria (heterotrophic bacteria, coliforms,
Escherichia coli
, and enterococci) and opportunistic pathogens (
Aeromonas
spp., enteropathogenic
E. coli
O157:H7,
Legionella
spp.,
Mycobacterium
spp., and
Pseudomonas
spp.), as well as algae. Using immunological methods,
E. coli
O157:H7 was detected in the effluent of only one system, but it was not detected at the sampling points, suggesting that its survival in the system was poor. Although all of the treatment systems effectively reduced the levels of bacteria in the effluent, bacteria regrew in the reservoir and distribution systems because of the loss of residual disinfectant and high assimilable organic carbon levels. In the systems with open reservoirs, algal growth reduced the water quality by increasing the turbidity and accumulating at the end of the distribution system. Opportunistic pathogens, notably
Aeromonas
,
Legionella
,
Mycobacterium
, and
Pseudomonas
, occurred more frequently than indicator bacteria (enterococci, coliforms, and
E. coli
). The
Mycobacterium
spp. were very diverse and occurred most frequently in membrane bioreactor systems, and
Mycobacterium cookii
was identified more often than the other species. The public health risk associated with these opportunistic pathogens in reclaimed water is unknown. Collectively, our results show the need to develop best management practices for reclaimed water to control bacterial regrowth and degradation of water before it is utilized at the point of use.
Aspergillus fumigatus Catalytic Glucokinase and Hexokinase: Expression Analysis and Importance for Germination, Growth, and Conidiation
Authors: Fleck Christian B. , Brock Matthias
Published: May 2010

Fungi contain several hexokinases, which are involved either in sugar phosphorylation or in carbon source sensing. Glucose and fructose phosphorylations appear to rely exclusively on glucokinase and hexokinase. Here, we characterized the catalytic glucokinase and hexokinase from the opportunistic human pathogen
Aspergillus fumigatus
and showed that both enzymes display different biochemical properties and play different roles during growth and development. Glucokinase efficiently activates glucose and mannose but activates fructose only to a minor extent. Hexokinase showed a high efficiency for fructose activation but also activated glucose and mannose. Transcript and activity determinations revealed high levels of glucokinase in resting conidia, whereas hexokinase was associated mainly with the mycelium. Consequentially, a glucokinase mutant showed delayed germination at low glucose concentrations, whereas colony growth was not overly affected. The deletion of hexokinase had only a minor impact on germination but reduced colony growth, especially on sugar-containing media. Transcript determinations from infected mouse lungs revealed the expression of both genes, indicating a contribution to virulence. Interestingly, a double-deletion mutant showed impaired growth not only on sugars but also on nonfermentable nutrients, and growth on gluconeogenic carbon sources was strongly suppressed in the presence of glucose. Furthermore, the
glkA hxkA
deletion affected cell wall integrity, implying that both enzymes contribute to the cell wall composition. Additionally, the absence of either enzyme deregulated carbon catabolite repression since mutants displayed an induction of isocitrate lyase activity during growth on glucose-ethanol medium. Therefore, both enzymes seem to be required for balancing carbon flux in
A. fumigatus
and are indispensable for growth under all nutritional conditions.
A
-Mating-Type Gene Expression Can Drive Clamp Formation in the Bipolar Mushroom Pholiota microspora (Pholiota nameko)
Authors: Yi Ruirong , Mukaiyama Hiroyuki , Tachikawa Takashi , Shimomura Norihiro , Aimi Tadanori
Published: May 2010

In the bipolar basidiomycete
Pholiota microspora
, a pair of homeodomain protein genes located at the
A
-mating-type locus regulates mating compatibility. In the present study, we used a DNA-mediated transformation system in
P. microspora
to investigate the homeodomain proteins that control the clamp formation. When a single homeodomain protein gene (
A3-hox1
or
A3-hox2
) from the
A3
monokaryon strain was transformed into the
A4
monokaryon strain, the transformants produced many pseudoclamps but very few clamps. When two homeodomain protein genes (
A3-hox1
and
A3-hox2
) were transformed either separately or together into the
A4
monokaryon, the ratio of clamps to the clamplike cells in the transformants was significantly increased to ca. 50%. We therefore concluded that the gene dosage of homeodomain protein genes is important for clamp formation. When the
sip
promoter was connected to the coding region of
A3-hox1
and
A3-hox2
and the fused fragments were introduced into NGW19-6 (
A4
), the transformants achieved more than 85% clamp formation and exhibited two nuclei per cell, similar to the dikaryon (NGW12-163 × NGW19-6). The results of real-time reverse transcription-PCR confirmed that
sip
promoter activity is greater than that of the native promoter of homeodomain protein genes in
P. microspora.
Thus, we concluded that nearly 100% clamp formation requires high expression levels of homeodomain protein genes and that altered expression of the
A
-mating-type genes alone is sufficient to drive true clamp formation.
Genome Analysis of
Moraxella catarrhalis
Strain RH4, a Human Respiratory Tract Pathogen
Authors: de Vries Stefan P. W. , van Hijum Sacha A. F. T. , Schueler Wolfgang , Riesbeck Kristian , Hays John P. , Hermans Peter W. M. , Bootsma Hester J.
Published: May 2010

Moraxella catarrhalis
is an emerging human-restricted respiratory tract pathogen that is a common cause of childhood otitis media and exacerbations of chronic obstructive pulmonary disease in adults. Here, we report the first completely assembled and annotated genome sequence of an isolate of
M. catarrhalis
, strain RH4, which originally was isolated from blood of an infected patient. The RH4 genome consists of 1,863,286 nucleotides that form 1,886 protein-encoding genes. Comparison of the RH4 genome to the ATCC 43617 contigs demonstrated that the gene content of both strains is highly conserved.
In silico
phylogenetic analyses based on both 16S rRNA and multilocus sequence typing revealed that RH4 belongs to the seroresistant lineage. We were able to identify almost the entire repertoire of known
M. catarrhalis
virulence factors and mapped the members of the biosynthetic pathways for lipooligosaccharide, peptidoglycan, and type IV pili. Reconstruction of the central metabolic pathways suggested that RH4 relies on fatty acid and acetate metabolism, as the genes encoding the enzymes required for the glyoxylate pathway, the tricarboxylic acid cycle, the gluconeogenic pathway, the nonoxidative branch of the pentose phosphate pathway, the beta-oxidation pathway of fatty acids, and acetate metabolism were present. Moreover, pathways important for survival under challenging
in vivo
conditions, such as the iron-acquisition pathways, nitrogen metabolism, and oxidative stress responses, were identified. Finally, we showed by microarray expression profiling that ∼88% of the predicted coding sequences are transcribed under
in vitro
conditions. Overall, these results provide a foundation for future research into the mechanisms of
M. catarrhalis
pathogenesis and vaccine development.
ExsA Recruits RNA Polymerase to an Extended −10 Promoter by Contacting Region 4.2 of Sigma-70
Authors: Vakulskas Christopher A. , Brutinel Evan D. , Yahr Timothy L.
Published: May 2010

ExsA is a member of the AraC family of transcriptional activators and is required for expression of the
Pseudomonas aeruginosa
type III secretion system (T3SS). ExsA-dependent promoters consist of two binding sites for monomeric ExsA located approximately 50 bp upstream of the transcription start sites. Binding to both sites is required for recruitment of σ
70
-RNA polymerase (RNAP) to the promoter. ExsA-dependent promoters also contain putative −35 hexamers that closely match the σ
70
consensus but are atypically spaced 21 or 22 bp from the −10 hexamer. Because several nucleotides located within the putative −35 region are required for ExsA binding, it is unclear whether the putative −35 region makes an additional contribution to transcription initiation. In the present study we demonstrate that the putative −35 hexamer is dispensable for ExsA-independent transcription from the P

exsC

promoter and that deletion of σ
70
region 4.2, which contacts the −35 hexamer, has no effect on ExsA-independent transcription from P

exsC

. Region 4.2 of σ
70
, however, is required for ExsA-dependent activation of the P

exsC

and P

exsD

promoters. Genetic data suggest that ExsA directly contacts region 4.2 of σ
70
, and several amino acids were found to contribute to the interaction.
In vitro
transcription assays demonstrate that an extended −10 element located in the P

exsC

promoter is important for overall promoter activity. Our collective data suggest a model in which ExsA compensates for the lack of a −35 hexamer by interacting with region 4.2 of σ
70
to recruit RNAP to the promoter.
The Cyclic Dipeptide Cyclo(Phe-Pro) Inhibits Cholera Toxin and Toxin-Coregulated Pilus Production in O1 El Tor
Vibrio cholerae
Authors: Bina Xiaowen R. , Bina James E.
Published: May 2010

Cyclo(Phe-Pro) is a cyclic dipeptide produced by multiple
Vibrio
species. In this work, we present evidence that cyclo(Phe-Pro) inhibits the production of the virulence factors cholera toxin (CT) and toxin-coregulated pilus (TCP) in O1 El Tor
Vibrio cholerae
strain N16961 during growth under virulence gene-inducing conditions. The cyclo(Phe-Pro) inhibition of CT and TCP production correlated with reduced transcription of the virulence regulator
tcpPH
and was alleviated by overexpression of
tcpPH
.
Mutations in the
Bacillus subtilis
β Clamp That Separate Its Roles in DNA Replication from Mismatch Repair
Authors: Dupes Nicole M. , Walsh Brian W. , Klocko Andrew D. , Lenhart Justin S. , Peterson Heather L. , Gessert David A. , Pavlick Cassie E. , Simmons Lyle A.
Published: May 2010

The β clamp is an essential replication sliding clamp required for processive DNA synthesis. The β clamp is also critical for several additional aspects of DNA metabolism, including DNA mismatch repair (MMR). The
dnaN5
allele of
Bacillus subtilis
encodes a mutant form of β clamp containing the G73R substitution. Cells with the
dnaN5
allele are temperature sensitive for growth due to a defect in DNA replication at 49°C, and they show an increase in mutation frequency caused by a partial defect in MMR at permissive temperatures. We selected for intragenic suppressors of
dnaN5
that rescued viability at 49°C to determine if the DNA replication defect could be separated from the MMR defect. We isolated three intragenic suppressors of
dnaN5
that restored growth at the nonpermissive temperature while maintaining an increase in mutation frequency. All three
dnaN
alleles encoded the G73R substitution along with one of three novel missense mutations. The missense mutations isolated were S22P, S181G, and E346K. Of these, S181G and E346K are located near the hydrophobic cleft of the β clamp, a common site occupied by proteins that bind the β clamp. Using several methods, we show that the increase in mutation frequency resulting from each
dnaN
allele is linked to a defect in MMR. Moreover, we found that S181G and E346K allowed growth at elevated temperatures and did not have an appreciable effect on mutation frequency when separated from G73R. Thus, we found that specific residue changes in the
B. subtilis
β clamp separate the role of the β clamp in DNA replication from its role in MMR.
Identification of Multiple Substrates of the StkP Ser/Thr Protein Kinase in
Streptococcus pneumoniae
Authors: Nováková Linda , Bezoušková Silvia , Pompach Petr , Špidlová Petra , Sasková Lenka , Weiser Jaroslav , Branny Pavel
Published: May 2010

Monitoring the external environment and responding to its changes are essential for the survival of all living organisms. The transmission of extracellular signals in prokaryotes is mediated mainly by two-component systems. In addition, genomic analyses have revealed that many bacteria contain eukaryotic-type Ser/Thr protein kinases. The human pathogen
Streptococcus pneumoniae
encodes 13 two-component systems and has a single copy of a eukaryotic-like Ser/Thr protein kinase gene designated
stkP
. Previous studies demonstrated the pleiotropic role of the transmembrane protein kinase StkP in pneumococcal physiology. StkP regulates virulence, competence, and stress resistance and plays a role in the regulation of gene expression. To determine the intracellular signaling pathways controlled by StkP, we used a proteomic approach for identification of its substrates. We detected six proteins phosphorylated on threonine by StkP continuously during growth. We identified three new substrates of StkP: the Mn-dependent inorganic pyrophosphatase PpaC, the hypothetical protein spr0334, and the cell division protein DivIVA. Contrary to the results of a previous study, we did not confirm that the α-subunit of RNA polymerase is a target of StkP. We showed that StkP activation and substrate recognition depend on the presence of a peptidoglycan-binding domain comprising four extracellular penicillin-binding protein- and Ser/Thr kinase-associated domain (PASTA domain) repeats. We found that StkP is regulated in a growth-dependent manner and likely senses intracellular peptidoglycan subunits present in the cell division septa. In addition,
stkP
inactivation results in cell division defects. Thus, the data presented here suggest that StkP plays an important role in the regulation of cell division in pneumococcus.
Comparison of genetic diversity between Canadian adapted genotypes and exotic germplasm of soybean
Authors: Iquira Elmer , Gagnon Éric , Belzile François
Published: May 2010

Soybean ( Glycine max (L.) Merr.) was domesticated in China and the greatest genetic diversity for this species is found in Asia. In contrast, in North America, soybean cultivars trace back to a small number of plant introductions from Asia and genetic diversity is typically quite limited. The purpose of this work was to measure and compare the genetic diversity in two sets of soybean lines. The first set (termed “local”) was composed of 100 lines used in a private breeding program in Quebec. The second set (termed “exotic”) was composed of 200 lines from elsewhere in the world (but mostly from Asia) and included a few lines of Glycine soja , the wild progenitor of cultivated soybean. Almost all the genotypes belonged to maturity groups between 000 and II. A total of 39 microsatellites (SSRs) were used to genotype the two collections. The number of alleles per locus was almost twice as great in the exotic set compared with the local set. Also, the number of “unique” alleles, i.e., those uniquely present in one set and absent in the other, was almost fivefold greater (191 vs. 37) in a subset of 108 exotic lines with good adaptation than among the local set. A genetic distance matrix, a UPGMA cluster analysis, and a principal coordinate analysis were conducted based on the SSR data. These analyses all indicated that the exotic set was much more diverse and formed a clearly distinct group from the local set. Interestingly, some of the lines showing the best adaptation to local conditions were quite distinctive in terms of their genotype and could potentially contribute useful novel genetic variation within the breeding program.