Successive bioanode regenerations to maintain efficient current production from biowaste.

The long-term operation of efficient bioanodes supplied with waste-derived organics is a key challenge for using bioelectrochemical systems as a waste valorization technology. Here, we describe a simple procedure that allowed maintaining highly efficient bioanodes supplied with biowaste. Current densities up to 14.8 A/m(2) were obtained with more than 40% of the electrons introduced as biowaste being recovered in the electrical circuit. Three fed-batch reactors were started at different biowaste loading rates. A decline of coulombic efficiencies between 22 and 31% was recorded depending on the reactor over the first 3 weeks of operation. A renewal procedure of the anode was thereafter implemented, which led to a recovery of initial performances. The second and the third renewal, allowed maintaining stable high level performances with coulombic efficiency of approximately 40% over at least 3 weeks. Electroactive biofilm dynamics were monitored using 16S rRNA-gene amplicon sequencing. Retrieved sequences were dominated by Geobacter sulfurreducens-related reads (37% of total sequences), which proportion however varied along the experiment. Interestingly, sequences affiliated to various Bacteroidetes groups were also abundant, suggesting an adaptation of the anodic biofilm to the degradation of biowaste through metabolic interactions between microbial community members.

Choice of different dyes to label tyrosine and nitrotyrosine.

In this work, we will present some attempts to analyze tyrosine and nitrotyrosine using capillary electrophoresis and either UV-Visible detection or laser-induced fluorescence (LIF) detection. An argon ion (488 nm) laser is used for fluorescein isothiocyanate (FITC) and 7-fluoro-4-nitro-2,1,3-benzoxadiazole (NBD-F). A near infrared (780 nm) laser is used for NIR 780 derivatives. The UV-Visible limit of detection is 2.5 microM whereas it is in the range of 30 nM for LIF detection.

Principle of pattern-signature synthesis and analysis based on double optical correlations.

Pattern-recognition problems for which patterns cannot be recognized directly but by their attitudes and/or behaviors is addressed. To analyze these attitudes, pattern signatures are generated from picture sequences. Two complementary signature synthesis algorithms are presented. The architecture is made up of two cascaded correlators. The first is used to create the signatures and the second to classify them. We focus our analysis on the case of optical implementations. Illustrations are given in the case of face recognition by attitudes (multisensor in the optronic imaging range) and moving-target recognition by behavior (in the radar imaging range).

Composite versus multichannel binary phase-only filtering.

Multichannel filtering and its inherent capacity for the implementation of data-fusion algorithms for high-level image processing, as well as composite filtering and its capacity for distortion-invariant pattern-recognition tasks, are discussed and compared. Both approaches are assessed by use of binary phase-only filters to simplify implementation issues. We discuss similarities and differences of these two solutions and demonstrate that they can be merged efficiently, giving rise to a new category of filters that we call composite-multichannel filters. We illustrate this comparison and the new filter design for the case of rotation-invariant fingerprint recognition. In particular, we show that the gain in terms of encoding capacity in the case of the composite-multichannel approach can be used efficiently to introduce multichannel-filter reconfigurability.

Purification of testosterone 5 alpha-reductase from human prostate by a four-step chromatographic procedure.

Nuclear membrane bound testosterone 5 alpha-reductase solubilized in active form from human prostatic tissue by 0.5% n-octyl beta-D-glucopyranoside was purified by a four-step chromatographic procedure including DEAE-Trisacryl ion exchange, hydroxylapatite adsorption, testosterone-Sepharose affinity and Sepharose 4B gel filtration. A purification of approximately 30-fold was achieved judging from the increase in the specific enzymatic activity. We have purified the acidic pH-optimum 5 alpha-reductase type 2 isoenzyme. The apparent molecular weight of the purified enzyme was estimated as 42,000 by SDS-PAGE. At the same time we isolated a 38 kDa protein characterized by a real affinity for testosterone and by a possible association to the 5 alpha-reductase enzyme.

Glycosylated nature of testosterone 5 alpha-reductase 2 purified from human prostate.

5 alpha-reductase 2 from human prostate solubilized into an active and stable form using a non-ionic detergent octyl glucoside was successfully purified using a four-step chromatographic procedure. The enzyme was obtained as an apparently homogeneous protein exhibiting an apparent molecular weight of 42 kDa upon SDS-PAGE. Con A, DBA, UEA-I, and RCA60 lectins recognized this protein. After treatment with O-glycosidase and neuraminidase, a protein of an apparent molecular weight about 30 kDa appeared. On the other hand, N-glycosidase treatment of this enzyme had no effect. These results indicate that the human prostate testosterone 5 alpha-reductase 2 is an O-glycosylated sialoglycoprotein with a peptide moiety of about 30 kDa; the oligosaccharide side chains contain mannose, N-acetyl galactosamine, fucose, galactose and sialic acids.

Characterization and solubilization of testosterone 17 beta-hydroxysteroid dehydrogenase in human hyperplastic prostate.

17 beta-Hydroxysteroid dehydrogenase is a membrane-bound enzyme in human prostate. Solubilization of this enzyme can only be obtained in the presence of detergents. The optimal solubilization mixture contained 50 mM Tris-HCl buffer pH 9.0, 20% glycerol, 0.1 M KCl and 5 mg/ml of the non-ionic detergent N-octyl glucoside. In these conditions, the soluble fraction contained more than 90% of the enzymatic activity. A 2.5-fold increase of specific activity was obtained during solubilization under optimal conditions.

Cloning, DNA sequencing and expression of (3-17)beta hydroxysteroid dehydrogenase from Pseudomonas testosteroni.

We describe the cloning, sequencing and overexpression of the (3-17)beta hydroxysteroid dehydrogenase gene of Pseudomonas testosteroni. A genomic library of Ps. testosteroni total DNA constructed from SauIIIA digests ligated to a lambda gt11 vector was probed with polyclonal antibody raised against purified enzyme. Subclones derived from a recombinant phage containing a 2661-base-pair insert were sequenced and found to contain an open reading frame of 765 base pairs that corresponds to a protein of 254 amino acid residues. A 1492-base-pair fragment was inserted into pBR322 plasmid vector and used to construct a strain of E. coli HB101 that overexpressed the steroid dehydrogenase gene.

Partial purification of 3 alpha- and 3 beta-hydroxysteroid dehydrogenases from human hyperplastic prostate. Comparison between the two enzymes.

3 alpha-Hydroxysteroid dehydrogenase (3 alpha-HSD) activity has been purified to homogeneity, the enzyme is a monomer with a Mw of 32,000 Da. 3 beta-Hydroxysteroid dehydrogenase (3 beta-HSD) activity has been partially purified and has an apparent Mw of 30,000 Da. Both enzymes have the same cofactor requirements, optimal pH. However, 3 beta-HSD appeared to be an integral protein dependent on protein environment for its activity while 3 alpha-HSD activity is a protein more loosely associated to membranes.

Unusually high rates of metabolism of DHT in cytosols of the quail uropygial gland.

The metabolism of DHT in the cytosol of the quail uropygial gland was found to be so high that the steroid was almost completely inactivated within 2 hours of incubation at 0 C. In these conditions, DHT cannot be used for the characterization of androgen receptors. By contrast, R 1881 and mibolerone, which are not metabolized, can be used as alternative ligands. Moreover, the extremely high metabolism of DHT questions the physiologic role of this steroid in the quail uropygial gland.

Metabolism of androgens in human hyperplastic prostate: evidence for a differential localization of the enzymes involved in the metabolism.

The subcellular distribution of 5 alpha-reductase, 17 beta-hydroxy steroid dehydrogenase, 3 alpha- and 3 beta-hydroxysteroid dehydrogenase activities was studied in human hyperplastic prostate. 5 alpha-reductase and 17 beta-hydroxysteroid dehydrogenase activities are located in the nuclear envelope. 3 alpha-hydroxysteroid dehydrogenase activity was almost equally distributed between cytosol and membranes, 3 beta-hydroxysteroid dehydrogenase activity was linked to all membranes. Direct testosterone metabolism (transformation into its active metabolite 5 alpha-DHT and into androstenedione, an inactive androgen) takes place only in the nucleus whereas indirect metabolism takes place mainly in the cytoplasm. These findings add new evidence for the mechanism of action of testosterone in prostatic tissue. Testosterone diffuses into the cell, migrates toward the nucleus and is transformed at the nuclear envelope level into two metabolites, DHT and androstenedione. After transformation into its active form, the hormone enters the nucleus whereas the inactive form is released into the cytoplasm. This metabolism could be seen as a control of the amount of active hormone entering the nucleus and being able to bind the androgen receptor.