| 1. |
- Coutinho, P. M., et al.
(författare)
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Post-genomic insights into the plant polysaccharide degradation potential of Aspergillus nidulans and comparison to Aspergillus niger and Aspergillus oryzae
- 2009
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Ingår i: Fungal Genetics and Biology. - : Elsevier BV. - 1096-0937 .- 1087-1845. ; 46:Suppl 1, s. S161-S169
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Tidskriftsartikel (refereegranskat)abstract
- The plant polysaccharide degradative potential of Aspergillus nidulans was analysed in detail and compared to that of Aspergillus niger and Aspergillus oryzae using a combination of bioinformatics, physiology and transcriptomics. Manual verification indicated that 28.4% of the A. nidulans ORFs analysed in this study do not contain a secretion signal, of which 40% may be secreted through a non-classical method. While significant differences were found between the species in the numbers of ORFs assigned to the relevant CAZy families, no significant difference was observed in growth on polysaccharides. Growth differences were observed between the Aspergilli and Podospora anserina, which has a more different genomic potential for polysaccharide degradation, suggesting that large genomic differences are required to cause growth differences oil polysaccharides, Differences were also detected between the Aspergilli in the presence Of putative regulatory sequences in the promoters of the ORFs Of this Study and correlation of the presence Of putative XlnR binding sites to induction by xylose was detected for A. niger. These data demonstrate differences at genome content, Substrate specificity of the enzymes and gene regulation in these three Aspergilli, which likely reflect their individual adaptation to their natural biotope. (C) 2008 Elsevier Inc. All rights reserved.
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| 2. |
- Jantra, Jongjit, et al.
(författare)
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Microbial biosensor for the analysis of 2,4-dichlorophenol
- 2005
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Ingår i: Analytical Letters. - 0003-2719. ; 38:7, s. 1071-1083
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Tidskriftsartikel (refereegranskat)abstract
- A flow injection cell-based biosensor was constructed for 2,4-dichlorophenol (DCP) analysis by using a Clark-type oxygen electrode as a transducer. A mixed bacterial culture capable to biodegrade DCP was immobilized between a Teflon membrane and a dialysis membrane and attached to the oxygen electrode. Optimization of the flow rate, the injection volume, the carrier buffer concentration, and pH was carried out. Under optimum conditions (100 mM phosphate buffer, pH 7.50; flow rate 0.10 mL min(-1); sample volume 100 mL), the sensor response was linear between 0.01 and 0.30 mM DCP. The detection limit was 0.02 mM DCP, and the sensor was quite stable during 5 days of operation.
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| 3. |
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| 4. |
- Duchemin, Benoit, et al.
(författare)
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All-cellulose composites by partial dissolution in the ionic liquid 1-butyl-3-methylimidazolium chloride
- 2009
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Ingår i: Composites. Part A, Applied science and manufacturing. - : Elsevier BV. - 1359-835X .- 1878-5840. ; 40:12, s. 2031-2037
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Tidskriftsartikel (refereegranskat)abstract
- Fully bio-based and biodegradable all-cellulose composites were prepared in the form of films by partial dissolution of two cellulose sources: a commercially available microfibrillated cellulose (MFC) and filter paper (FP). The solvent selected for this work was the ionic liquid 1-butyl-3-methylimidazolium chloride ([C4mim]Cl). Both cellulose sources were partially dissolved at 80 °C and consolidated by partial dissolution, resulting in excellent mechanical properties. X-ray diffraction and electron microscopy demonstrated that partial dissolution was a viable path to transform FP into a continuous paracrystalline matrix reinforced with cellulose I crystallites. In contrast, partially dissolved MFC was not as thoroughly dissolved and large amounts of undissolved material were still visible along the center line of the films after the longest dissolution times. Consequently, partially dissolved MFC retained its initially high crystallinity. The degree of polymerization of the materials after dissolution was significantly reduced.
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| 5. |
- Normand, Philippe, et al.
(författare)
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Genome characteristics of facultatively symbiotic Frankia sp. strains reflect host range and host plant biogeography.
- 2007
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Ingår i: Genome Research. - : Cold Spring Harbor Laboratory. - 1088-9051. ; 17:1, s. 7-15
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Tidskriftsartikel (refereegranskat)abstract
- Soil bacteria that also form mutualistic symbioses in plants encounter two major levels of selection. One occurs during adaptation to and survival in soil, and the other occurs in concert with host plant speciation and adaptation. Actinobacteria from the genus Frankia are facultative symbionts that form N2-fixing root nodules on diverse and globally distributed angiosperms in the "actinorhizal" symbioses. Three closely related clades of Frankia sp. strains are recognized; members of each clade infect a subset of plants from among eight angiosperm families. We sequenced the genomes from three strains; their sizes varied from 5.43 Mbp for a narrow host range strain (Frankia sp. strain HFPCcI3) to 7.50 Mbp for a medium host range strain (Frankia alni strain ACN14a) to 9.04 Mbp for a broad host range strain (Frankia sp. strain EAN1pec.) This size divergence is the largest yet reported for such closely related soil bacteria (97.8%–98.9% identity of 16S rRNA genes). The extent of gene deletion, duplication, and acquisition is in concert with the biogeographic history of the symbioses and host plant speciation. Host plant isolation favored genome contraction, whereas host plant diversification favored genome expansion. The results support the idea that major genome expansions as well as reductions can occur in facultative symbiotic soil bacteria as they respond to new environments in the context of their symbioses.
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| 6. |
- Ponsot, Elodie, 1973-, et al.
(författare)
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Exercise training in normobaric hypoxia in endurance runners. II. Improvement of mitochondrial properties in skeletal muscle
- 2006
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Ingår i: Journal of applied physiology. - Betsheda, USA : American Physiological Society. - 8750-7587 .- 1522-1601. ; 100:4, s. 1249-57
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Tidskriftsartikel (refereegranskat)abstract
- This study investigates whether adaptations of mitochondrial function accompany the improvement of endurance performance capacity observed in well-trained athletes after an intermittent hypoxic training program. Fifteen endurance-trained athletes performed two weekly training sessions on treadmill at the velocity associated with the second ventilatory threshold (VT2) with inspired O2 fraction = 14.5% [hypoxic group (Hyp), n = 8] or with inspired O2 fraction = 21% [normoxic group (Nor), n = 7], integrated into their usual training, for 6 wk. Before and after training, oxygen uptake (VO2) and speed at VT2, maximal VO2 (VO2 max), and time to exhaustion at velocity of VO2 max (minimal speed associated with VO2 max) were measured, and muscle biopsies of vastus lateralis were harvested. Muscle oxidative capacities and sensitivity of mitochondrial respiration to ADP (Km) were evaluated on permeabilized muscle fibers. Time to exhaustion, VO2 at VT2, and VO2 max were significantly improved in Hyp (+42, +8, and +5%, respectively) but not in Nor. No increase in muscle oxidative capacity was obtained with either training protocol. However, mitochondrial regulation shifted to a more oxidative profile in Hyp only as shown by the increased Km for ADP (Nor: before 476 +/- 63, after 524 +/- 62 microM, not significant; Hyp: before 441 +/- 59, after 694 +/- 51 microM, P < 0.05). Thus including hypoxia sessions into the usual training of athletes qualitatively ameliorates mitochondrial function by increasing the respiratory control by creatine, providing a tighter integration between ATP demand and supply.
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| 7. |
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| 8. |
- Treebak, Jonas T, et al.
(författare)
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AMPK-mediated AS160 phosphorylation in skeletal muscle is dependent on AMPK catalytic and regulatory subunits.
- 2006
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 55:7, s. 2051-2058
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Tidskriftsartikel (refereegranskat)abstract
- AMP-activated protein kinase (AMPK) is a heterotrimeric protein that regulates glucose transport mediated by cellular stress or pharmacological agonists such as 5-aminoimidazole-4-carboxamide 1 beta-D-ribonucleoside (AICAR). AS160, a Rab GTPase-activating protein, provides a mechanism linking AMPK signaling to glucose uptake. We show that AICAR increases AMPK, acetyl-CoA carboxylase, and AS160 phosphorylation by insulin-independent mechanisms in isolated skeletal muscle. Recombinant AMPK heterotrimeric complexes (alpha 1 beta 1 gamma l and alpha 2 beta 2 gamma 1) phosphorylate AS160 in a cell-free assay. In mice deficient in AMPK signaling (alpha 2 AMPK knockout [KO], alpha 2 AMPK kinase dead [KD], and gamma 3 AMPK KO), AICAR effects on AS160 phosphorylation were severely blunted, highlighting that complexes containing alpha 2 and gamma 3 are necessary for AICAR-stimulated AS160 phosphorylation in intact skeletal muscle. Contraction-mediated AS160 phosphorylation was also impaired in alpha 2 AMPK KO and KD but not gamma 3 AMPK KO mice. Our results implicate AS160 as a downstream target of AMPK.
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| 9. |
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