Heavy metal tolerant Pseudomonas protegens isolates from agricultural well water in northeastern Algeria with plant growth promoting, insecticidal and antifungal activities

The application of plant growth promoting bacteria (PGPB) with biocontrol activities as inoculants of crop plants against phytopathogenic fungi and insect pests provide a biological alternative to the use of agrochemicals. Two Pseudomonas protegens strains were isolated from agricultural well water in a heavy metal contaminated area near Bejaia, northeastern Algeria. The isolates S4LiBe and S5LiBe had 16S rRNA gene sequence similarities of 99.4%–99.7% with P. protegens CHA0T and other P. protegens strains. The phenotypic profiles tested with BIOLOG-GN2-microplates showed differences in 12 of 95 carbon sources tested, as compared to the type strain P. protegens CHA0T. The isolates S4LiBe and S5LiBe showed plant growth promoting potential which is commonly associated with the production of the phytohormone indole acetic acid and siderophores and the solubilization of insoluble phosphate. In addition, they produce chitinase and other polymer degrading enzymes. As the strains S4LiBe and S5LiBe were isolated from heavy metal polluted well water, they are resistant against several heavy metals (2.0 mM K2Cr2O7 and 3.0 mM CoSO4, HgSO4, CdSO4 8H2O and PbCl2), while the reference strain P. protegens CHA0T was very sensitive to Hg2+ and Cd2+ and had lower tolerance towards Co2+ and Pb2+. The isolates S4LiBe and S5LiBe were active in mycelial growth inhibition assays against Botrytis cinerea, Verticillium dahliae, Fusarium graminearum, Aspergillus niger and Aspergillus flavus (growth inhibition between 88% and 48%). Furthermore, S4LiBe and S5LiBe showed effective insecticidal activities, when tested in the Galleria injection assay and they were tested positive for the insect toxin gene fitD alike the reference strain CHA0T. Finally, inoculation of barley seeds with S5LiBe in non-polluted agricultural soil significantly stimulated the germination rate and growth of seedlings, with increased shoot length (11.96 cm ± 0.59), shoot and root fresh weight (0.10 g ± 0.009, 0.04 g ± 0.006), shoot and root dry weight (0.075 g ± 0.003, 0.03 g ± 0.007) as compared to non-inoculated plants (10.23 cm ± 0.84, 0.06 g ± 0.007, 0.025 g ± 0.006, 0.047 g ± 0.006, and 0.016 g ± 0.004, respectively). In heavy metal contaminated soil, inoculation with strain S5LiBe resulted in similar increase of germination rate and growth parameters of barley like in the non-polluted soil, while P. protegens CHA0T inoculated plants were not stimulated. Thus, the heavy metal tolerant isolates S4LiBe and S5LiBe have a potential as beneficial bacteria for agricultural application even in heavy metal polluted soils, e.g. for the stimulation of biomass crops. The demonstration of successful isolation from agricultural well water may open more ready access for a wide variety of this kind of beneficial bacteria for agricultural application

Fabrication flaws and reliability in MEMS thin film polycrystalline flow sensor

International audienceA micro hot wire anemometer sensor has been constructed. The process consists in depositing a thin doped polycrystalline silicon layer on silicon substrate, using a micro-machined technique. This paper discusses the reliability and the fabrication flaws of this sensor. The different steps of fabrication are oxidation, deposit, photolithography, chemical attack, ionic implantation and annealing. An additional step, allowing the release of the suspended structures, is added. With each technological process step, a certain number of problems can be met. Each of these problems can potentially give rise to a defect of the final structure. Various tests are carried out on the final structure to make a first approach of the micro flow sensor flaws

Innovative cell therapy in the treatment of serious adverse events related to both chemo-radiotherapy protocol and acute myeloid leukemia syndrome: The infusion of mesenchymal stem cells post-treatment reduces hematopoietic toxicity and promotes hematopoietic reconstitution

Bone marrow stroma is damaged by chemotherapy and irradiation protocol. Bone marrow microenvironment supports haematopoiesis and comprises Mesenchymal Stem Cells (MSCs). Coinfusion of MSCs with hematopoietic stem cells (HSC) improves engraftment and accelerates haematopoietic recovery. Stroma-derived factor-1 (SDF-1) is a chemotactic factor which plays a crucial role in stem cell transplantation by enhancing the ability of HSC to engraft. In this study expression of SDF-1 in bone marrow MSCs and the level of Colony Forming Unit Fibroblast (CFU-F) were evaluated in 8 patients with Acute Myeloid leukemia (AML). Evaluation was done at diagnosis and after induction/consolidation chemotherapy before the onset of haematopoietic stem cell transplantation (HSCT). CFU-F frequency increases from diagnosis to remission. Nevertheless level of stromal derived factor-1 (SDF-1) transcripts in bone marrow MSCs of patients with AML stays low. Considering the role of SDF-1 in the homing of HSC, the consequences of SDF-1 deficiency observed in this study might be deleterious on the engraftment after HSCT and haematopoietic recovery. The whole result of this clinical study is an argument for MSC infusion to restore a normal level of SDF1 in the bone marrow microenvironment that could reduce hematopoietic toxicity of chemotherapy and improve HSC engraftment after HSCT. © 2013 Bentham Science Publishers

Growth stimulation of barley and biocontrol effect on plant pathogenic fungi by a <em>Cellulosimicrobium</em> sp. strain isolated from salt-affected rhizosphere soil in northwestern Algeria.

The plant growth promoting effect of bacterial isolates from salt-affected agricultural rhizospheric soil from Bejaia, Algeria, on barley seedlings as well as biological control abilities of these isolates against phytopathogenic fungi were determined. Four isolates stimulated significantly germination and growth of barley seedlings in an axenic test system and in soil pots. Isolate S16 (Cellulosimicrobium sp.) stimulated the growth of barley seedlings by 185% (stem height of 13.0&plusmn;0.11cm) over non-inoculated control seedlings (7.0&plusmn;0.12cm). Cellulosimicrobium sp. S16 was found also superior in mycelial growth inhibition assays against the plant pathogenic fungi Botrytis cinerea, Fusarium oxysporum and Verticillium dahliae. Furthermore, several plant growth promoting traits (production of indole acetic acid, inorganic phosphate solubilization, siderophore production) and production of enzymes beneficial for soil fertility (protease, chitinase, amylase and urease) were identified. However, no evidence for nitrogen fixation was found by testing acetylene reduction and the presence of nif-genes. Based on comparative sequence analysis of almost full length 16S-rRNA coding gene fragments, Cellulosimicrobium sp. S16 exhibits the highest similarity of 99.7% to Cellulosimicrobium cellulans (accession number AY665978). Cellulosimicrobium sp. S16 could be a successful candidate for the application as a plant growth promoting inoculant

Human mesenchymal stem cell responses to hydrostatic pressure and shear stress

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Study of microwave and convective drying kinetics of pea pods (Pisum sativum L.): A new modeling approach using support vector regression methods optimized by dragonfly algorithm techniques

Machine learning and mathematical modeling techniques have been conducted to model the thin layer drying kinetics of pea pods, under either microwave or conventional air drying,. The effect of nine different microwave output powers (200-1000 W) and five different ventilated oven temperatures (40, 60, 80, 100, and 120 &amp; DEG;C) on drying kinetics was studied. The experimental drying rates were fitted to 11 literature semi-empirical models to determine the kinetic parameters, finding the higher goodness-of-fit for the Midilli et al. model (average R-2 = 0.999 for both drying methods). Moreover, the data were modeled using support vector machine (SVM) for regression which was optimized with dragonfly algorithm (DA) technique. The best result was obtained by Gaussian kernel with the optimal parameters sigma, C, and epsilon values estimated as 0.2871, 78.45, and 0, respectively. The small root mean square error (RMSE = 0.0132) and the high determination coefficient (R-2 = 0.9983) values proved how robust the SVM model is. DA-SVM techniques can reliably be utilized to describe the thin layer drying kinetics of pea pods. It is useful to provide models that can assist in the development of food process control algorithms, and provided insights into complex processes, for the technological design of microwave or convective drying for pea pods preservation. Practical applications Drying of by-products from pea processing industry was investigated as a critical step prior to their valorization. The drying of pea pods has never been investigated before which is the case of the present study whose objective was to study and model the microwave and convective drying kinetics of pea pods. Our research work reported that the Midilli et al. model was the most appropriate to describe the thin layer drying kinetics of pea pods for both drying methods, but mathematical drying models, although a useful tool, remains empirical in nature and product specific. Because of these limitations the new model DA-SVM, developed using artificial intelligence techniques, can reliably be used to describe the nonlinear behavior of pea pods drying. These results could be further used for scale up calculation, which would further allow industrial scale preservation by microwave or convective drying of pea pods

Mesenchymal stem cells home to injured tissues when co-infused with hematopoietic cells to treat a radiation-induced multi-organ failure syndrome

Background: Recent studies have suggested that ex vivo expansion of autologous hematopoietic cells could be a therapy of choice for the treatment of bone marrow failure. We investigated the potential of a combined infusion of autologous ex vivo expanded hematopoietic cells with mesenchymal (MSCs) for the treatment of multi-organ failure syndrome following irradiation in a non-human primate model. Methods: Hematopoietic cells and MSCs were expanded from bone marrow aspirates. MSCs were transduced with the gene encoding for the green fluorescent protein (e-GFP), in order to track them following infusion. Twelve animals were studied. Nine animals received total-body irradiation at 8 Gy from a neutron/gamma source thus resulting in heterogeneous exposure; three animals were sham-irradiated. The animals were treated with expanded hematopoietic stem cells and MSCs, expanded hematopoietic stem cells alone, or MSCs alone. Unmanipulated bone marrow cell transplants were used as controls. Results: Depending on the neutron/gamma ratio, an acute radiation sickness of varying severity but of similar nature resulted. GFP-labeled cells were found in the injured muscle, skin, bone marrow and gut of the treated animals via PCR up to 82 days post-infusion. Conclusions: This is the first evidence of expanded MSCs homing in numerous tissues following a severe multi-organ injury in primates. Localization of the transduced MSCs correlated to the severity and geometry of irradiation. A repair process was observed in various tissues. The plasticity potential of the MSCs and their contribution to the repair process in vivo remains to be studied. Copyright © 2003 John Wiley & Sons, Ltd

FGFR3 overactivation in the brain is responsible for memory impairments in Crouzon syndrome mouse model

International audienceCrouzon syndrome with acanthosis nigricans (CAN, a rare type of craniosynostosis characterized by premature suture fusion and neurological impairments) has been linked to a gain-of-function mutation (p.Ala391Glu) in fibroblast growth factor receptor 3 (FGFR3). To characterize the CAN mutation's impact on the skull and on brain functions, we developed the first mouse model (Fgfr3 A385E/+) of this syndrome. Surprisingly, Fgfr3 A385E/+ mice did not exhibit craniosynostosis but did show severe memory impairments, a structurally abnormal hippocampus, low activity-dependent synaptic plasticity, and overactivation of MAPK/ERK and Akt signaling pathways in the hippocampus. Systemic or brain-specific pharmacological inhibition of FGFR3 overactivation by BGJ398 injections rescued the memory impairments observed in Fgfr3 A385E/+ mice. The present study is the first to have demonstrated cognitive impairments associated with brain FGFR3 overactivation, independently of skull abnormalities. Our results provide a better understanding of FGFR3's functional role and the impact of its gain-of-function mutation on brain functions. The modulation of FGFR3 signaling might be of value for treating the neurological disorders associated with craniosynostosis