Insights into the mechanisms of desiccation resistance of the Patagonian PAH-degrading strain Sphingobium sp. 22B

Aim: To analyze the physiological response of Sphingobium sp. 22B to water stress. Methods and results:The strain was grown under excess of carbon source and then submitted to low (60RH) and high (18RH) water stress conditions for 96 h. Quantification of trehalose, glycogen, polyhydroxybutyrate (PHB), and transmission electron microscopy (TEM) was studied. Genes linked with desiccation were searched in Sphingobium sp. 22B and Sphingomonas "sensu latu" genomes and their transcripts were quantified by Real-Time PCR. Results showed that, in absence of water stress, strain 22B accumulated 4.76± 1.41% of glycogen, 0.84± 1.62% of trehalose and 44.9± 6.4% of PHB per cellular dry weight. Glycogen and trehalose were mobilized in water stresses conditions, this mobilization was significantly higher in 60RH in comparison to 18RH. Gene treY was upregulated 6-fold change in 60RH relative to 18RH. TEM and quantification of PHB revealed that PHB was mobilized under 60RH condition accompanied by the downregulation of the phbB gene. TEM images showed an extracellular amorphous matrix in 18RH and 60RH. Major differences were found in the presence of aqpZ and trehalose genes between strain 22B and Sphingomonas genomes. Conclusion: Strain 22B showed a carbon conservative metabolism capable of accumulation of three types of endogenous carbon sources. The strain responds to water stress by changing the expression pattern of genes related with desiccation, formation of an extracellular amorphous matrix and mobilization of the carbon sources according to the degree of water stress. Trehalose, glycogen and PHB may have multiple functions in different degrees of desiccation. The robust endowment of molecular responses to desiccation shown in Sphingobium sp. 22B could explain its survival in semiarid soil.Significance and Impact of the studyUnderstanding the physiology implicated in the toleration of the PAH-degrading strain Sphingobium sp 22B to environmental desiccation may improve the bioaugmentation technologies in semiarid hydrocarbons contaminated soils.Centro de Investigación y Desarrollo en Fermentaciones Industriale

Insights into the mechanisms of desiccation resistance of the Patagonian PAH-degrading strain Sphingobium sp. 22B

AimTo analyze the physiological response of Sphingobium sp. 22B to water stress.Methods and resultsThe strain was grown under excess of carbon source and then submitted to low (60RH) and high (18RH) water stress conditions for 96 h. Quantification of trehalose, glycogen, polyhydroxybutyrate (PHB), and transmission electron microscopy (TEM) was studied. Genes linked with desiccation were searched in Sphingobium sp. 22B and Sphingomonas ?sensu latu? genomes and their transcripts were quantified by Real-Time PCR. Results showed that, in absence of water stress, strain 22B accumulated 4.76± 1.41% of glycogen, 0.84± 1.62% of trehalose and 44.9± 6.4% of PHB per cellular dry weight. Glycogen and trehalose were mobilized in water stresses conditions, this mobilization was significantly higher in 60RH in comparison to 18RH. Gene treY was upregulated 6-fold change in 60RH relative to 18RH. TEM and quantification of PHB revealed that PHB was mobilized under 60RH condition accompanied by the downregulation of the phbB gene. TEM images showed an extracellular amorphous matrix in 18RH and 60RH. Major differences were found in the presence of aqpZ and trehalose genes between strain 22B and Sphingomonas genomes.ConclusionStrain 22B showed a carbon conservative metabolism capable of accumulation of three types of endogenous carbon sources. The strain responds to water stress by changing the expression pattern of genes related with desiccation, formation of an extracellular amorphous matrix and mobilization of the carbon sources according to the degree of water stress. Trehalose, glycogen and PHB may have multiple functions in different degrees of desiccation. The robust endowment of molecular responses to desiccation shown in Sphingobium sp. 22B could explain its survival in semiarid soil.Significance and Impact of the studyUnderstanding the physiology implicated in the toleration of the PAH-degrading strain Sphingobium sp 22B to environmental desiccation may improve the bioaugmentation technologies in semiarid hydrocarbons contaminated soils.Fil: Madueño, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Coppotelli, Bibiana Marina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Festa, Sabrina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Alvarez, H. M.. Universidad Nacional de la Patagonia "San Juan Bosco". Instituto de Biociencias de la Patagonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biociencias de la Patagonia; ArgentinaFil: Morelli, Irma Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; Argentin

Thioredoxin 80-Activated-Monocytes (TAMs) Inhibit the Replication of Intracellular Pathogens

BACKGROUND: Thioredoxin 80 (Trx80) is an 80 amino acid natural cleavage product of Trx, produced primarily by monocytes. Trx80 induces differentiation of human monocytes into a novel cell type, named Trx80-activated-monocytes (TAMs). PRINCIPAL FINDINGS: In this investigation we present evidence for a role of TAMs in the control of intracellular bacterial infections. As model pathogens we have chosen Listeria monocytogenes and Brucella abortus which replicate in the cytosol and the endoplasmic reticulum respectively. Our data indicate that TAMs efficiently inhibit intracellular growth of both L. monocytogenes and B. abortus. Further analysis shows that Trx80 activation prevents the escape of GFP-tagged L. monocytogenes into the cytosol, and induces accumulation of the bacteria within the lysosomes. Inhibition of the lysosomal activity by chloroquine treatment resulted in higher replication of bacteria in TAMs compared to that observed in control cells 24 h post-infection, indicating that TAMs kill bacteria by preventing their escape from the endosomal compartments, which progress into a highly degradative phagolysosome. SIGNIFICANCE: Our results show that Trx80 potentiates the bactericidal activities of professional phagocytes, and contributes to the first line of defense against intracellular bacteria

Some results of GARTEUR Action Group HC-AG 19 on methods for improvement of structural dynamic finite element models

The issue of vibration in helicopters is of major concern to operators. This requires close attention to the vehicle dynamics. The ability to faithfully simulate and optimise vehicle response, structural modifications, vehicle updates, the addition of stores and equipment is the key to producing a low vibration helicopter. GARTEUR Action Group, HC-AG 14, concluded that helicopter dynamic models are still deficient in their capability to predict airframe vibration. The AG looked at the methods for improving the model correlation with modal test data along with the suitability of existing shake test methods. The helicopter structure tested in AG14 was suspended in the laboratory. However, this is not the operational environment where there are very significant mass, inertia and gyroscopic effects from the rotor systems. Nowadays, modal analysis consists of two principal approaches: experimental modal analysis (EMA) and operational modal analysis (OMA). The EMA evaluates the modal parameters by considering that the excitation and the response of the system are both measurable. The OMA evaluates the modal parameters using only the measured response. The lack of knowledge of the input is replaced by the assumption that the input is a distributed stochastic load, constant in a broad frequency band, e.g. white noise, and uncorrected in space. This hypothesis, nevertheless, is restrictive in rotorcraft applications, because in these cases the load is characterized by harmonic components, i.e. deterministic signals, originating from the rotating parts. A new action group HC-AG19 was formed to study the benefit of using in-flight dynamic data for improving finite element models. Methodologies were assessed to evaluate vibration measurements from flight tests. The objective is to extract modal parameters and demonstrate that the dynamic model can be updated using this data. This paper presents one of the approaches developed by the University of Rome "La Sapienza"

Integrated sensor system for structural integrity and load monitoring of wind turbines

Development of an integrated Fiber Bragg Grating (FBG) structural health monitoring (SHM) system for a composite horizontal axis wind turbine blade is reported in this article. The SHM systems are expected to make significant reduction in the operational cost of wind turbines by optimizing the maintenance, yielding maximum service life of the wind turbine at minimum maintenance cost. Recently, the SHM systems are receiving even more attention due to the current trend in designing larger wind turbines in order to increase the efficiency. Increasing their size subjects them to larger operational loads and thus demands precise and real-time information about how the system is performing. The FBG sensor as SHM sensor has many advantages over other conventional sensors. Providing real-time information about structural integrity and operational load can be used in conjunction with other methods to decrease the overall energy cost. This paper discusses laboratory scale experimental setup for validation of FBG as a strain sensor to be used in SHM. Validation methods include a comparison of static strain measured with a resistive strain gauge to the FBG, and a modal analysis done with the FBGs compared to accelerometers