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See detailChitin biomass in marine sediments
Poulicek, Mathieu ULg; Jeuniaux, Charles ULg

in Skjak-Braek, A. (Ed.) Chitin and Chitosan (1988)

One hundred marine sediments of various origins were screened in order to evaluate their chitin biomass. Our purpose was to assess the detritic chitin stocks in order to find some potential new source of ... [more ▼]

One hundred marine sediments of various origins were screened in order to evaluate their chitin biomass. Our purpose was to assess the detritic chitin stocks in order to find some potential new source of chitin. The chitin biomass of marine sediments is very diversified, from 2 up to 2800 ug g-1 decalcified sediment (DS). Most sediments have low or very low chitin biomass (67% under 100 ug g-1 DS). No significant difference relmated to depth nor climatic influence was found except that all sediments richer in chitin (above 300 ug g-1 DS) are on the continental shelf (above 200m dephth). Actually, the chitin content is highter in coarse, much calcified sediments of organoclastic origin ; bryozoa and shelly sands and gravels are the richest. The powerful hydrolytic activity of microorganisms lower the steady state equilibrium level between chitin input and weathering, so most "unprotected" chitin is weathered very soon after settling. Marine sediments appears thus as a non comprtitive potential industrial chitin source. [less ▲]

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See detailChitin in biogeochemical cycles : Abstract 202
Jeuniaux, Charles ULg; Seki, H.

Conference (1990, August)

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See detailChitin location and subcellular organization during heterologous expression of chitin deacetylase in yeast Pichia pastoris
Jaspar-Versali, Marie-France ULg; Aifa, Karim; Compère, Philippe ULg et al

in Domard, Alain; Jeuniaux, Charles; Muzzarelli, Ricardo (Eds.) et al Advances in chitin sciences, volume I (1996)

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See detailChitin production by animals and natural communities in marine environment
Jeuniaux, Charles ULg; Bussers, Jean-Claude ULg; Voss-Foucart, M.F. et al

in Muzzarelli, R.; Jeuniaux, Charles; Gooday, G.W. (Eds.) Chitin in nature and technology (1986)

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See detailChitin-glucan complex production by Komagataella pastoris: downstream optimization and product characterization
Farinha, Inês; Duarte, Paulo; Pimentel, Ana et al

in Carbohydrate Polymers (2015), 130

Purified chitin-glucan complex (CGCpure) was extracted from Komagataella pastoris biomass using a hot alkaline treatment, followed by neutralization and repeated washing with deionised water. The co ... [more ▼]

Purified chitin-glucan complex (CGCpure) was extracted from Komagataella pastoris biomass using a hot alkaline treatment, followed by neutralization and repeated washing with deionised water. The co-polymer thus obtained had a glucan:chitin molar ratio of 75:25 and low protein and inorganic salts contents (3.0 and 0.9 wt%, respectively). CGCpure had an average molecular weight of 4.9 × 105 Da with a polydispersity index of 1.7, and a crystallinity index of 50%. Solid-state NMR provided structural insight at the co-polymer. X-ray diffraction and FTIR analysis suggest that CGCpure has b-chitin in its structure. CGCpure presented an endothermic decomposition peak at 315 oC, assigned to the degradation of the saccharide structures. This study revealed that K. pastoris CGC has properties similar to other chitinous biopolymers and may represent an attractive alternative to crustacean chitin derived-products, being a reliable raw material for the development of new/improved pharmaceutical, cosmetic or food products. [less ▲]

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See detailChitin-Glucan, a natural cell scaffold for skin rejuvenation: in vivo safety and efficacy.
Gautier, S.; Xhauflaire-Uhoda, Emmanuelle; Gonry, P. et al

in International Journal of Cosmetic Science (2008), 30

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See detailChitinase : an addition to the list of hydrolases in the digestive tract of vertebrates
Jeuniaux, Charles ULg

in Nature (1961), 192(4798), 135-136

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See detailChitinase et bactéries chitinolytiques dans le tube digestif d'un cloporte (Porcellio Scaber Latr.) (Isope, Oniscide)
Jeuniaux, Charles ULg

in Archives Internationales de Physiologie et de Biochimie (1956), 64(4), 583-586

Le tube digestif de Porcellio scaber Latr. (Isope Oniscide) contient une chitinase. Il héberge une flore bactérienne chitinolytique quantitativement plus abondante que celle du milieu extérieur et ... [more ▼]

Le tube digestif de Porcellio scaber Latr. (Isope Oniscide) contient une chitinase. Il héberge une flore bactérienne chitinolytique quantitativement plus abondante que celle du milieu extérieur et qualitativement différente. Ces bactéries chitinolytiques pourraient être responsables de l'élaboration de la chitinase du cloporte. [less ▲]

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See detailLa chitinase exuviale des Insectes
Jeuniaux, Charles ULg

in Mémoires de la Société Royale d'Entomologie de Belgique (1955), 27

1. Il est prouvé que le liquide exuvial des Insectes, sécrété peu avant la mue, contient une chitinase. Celle-ci dissout une partie importante des strates internes de la vieille cuticule (endocuticule ... [more ▼]

1. Il est prouvé que le liquide exuvial des Insectes, sécrété peu avant la mue, contient une chitinase. Celle-ci dissout une partie importante des strates internes de la vieille cuticule (endocuticule). Chez Platysamia cecropia L., le liquide exuvial est d'abord sécrété sous forme de gel, inactif au point de vue enzymatique. 2. Les extraits aqueux d'exuvies larvaires et nymphales sont doués de propriétés chitinolytiques, dues à la présence de liquide exuvial adhérent à la surface interne des exuvies. Certaines exuvies, telles que celles des nymphes de Tenebrio et des larves de Carausius, sont particulièrement riches en chitinase exuviale. 3. Chez toutes les espèces d'Insectes étudiées jusqu'à présent, on a pu mettre en évidence l'intervention d'une chitinase au moment de la mue. 4. La cinétique de la chitinase des exuvies ou du liquide exuvial de Bombyx mori et de Tenebrio molitor est identique, et ne diffère guère de celle des autres chitinases connues (pH optimum : entre 4.9 et 5.5 ; température optimale : 37° C.). [less ▲]

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See detailChitinases
Jeuniaux, Charles ULg

in Archives Internationales de Physiologie et de Biochimie (1958), 29(522), 644-650

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See detailChitinases et chitobiases dans les tissus épidermiques, l'hépatopancréas et le tube digestif du crabe
Jeuniaux, Charles ULg

in Archives Internationales de Physiologie et de Biochimie (1960), 68(4), 684-685

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See detailChitine "libre" et chitine "masquée" dans les structures squelettiques d'Invertébrés
Jeuniaux, Charles ULg

in Archives Internationales de Physiologie et de Biochimie (1964), 72(2), 329-330

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See detailLa chitine dans le règne animal
Jeuniaux, Charles ULg

in Bulletin de la Société Zoologique de France (1982), 107(3), 363-386

Chitin, a high linear polymer composed of N-acetylglucosamine residues attached by B-1,4 glycosidic linkages, is often used in the animal kingdom as an organic support of cuticular and exoskeletal ... [more ▼]

Chitin, a high linear polymer composed of N-acetylglucosamine residues attached by B-1,4 glycosidic linkages, is often used in the animal kingdom as an organic support of cuticular and exoskeletal structures. A specific enzymatic method allows the detection and quantitative measurement of chitin, and may be suitable for pointing out the existence of some linkage to other constituents ("free" and "bound" chitin). Chitin is mainly organised, at the ultrastructural level, in microfibrils (glycoprotein complex). Chitin is a constituent of diverse structures, built up by Protozoa, mainly Ciliates (kystic membranes, sheaths). In Diblastic Metazoa, chitin is secreted by the ectoderm of most Hydrozoa and of some Octocorallia and Scyphozoa, but is completely lacking in Porifera and Ctenophora. Among Triblastic Metazoa, chitin is frequently secreted by the ectoderm of Spiralia, as well Pseudocoelomates (mainly in egg envelopes) as Protostomian Coelomates (in cuticles, shells, setae, operculae, scales, spicules, etc.), with the exception of Sipunculida. Chitin does not seem to be secreted at all by Acoelomates. Peritrophic membranes of Arthropoda and Annelida seem to be of endodermic origin, as well as different types of cuticular formations in the stomach of many Molluscs. Chitin is a frequent constituent of ectodermic productions in Lophophorates (tubes, ectocyst, shells), in Pogonophora (tubes) and in Chaetognatha. The secretion of this polysaccharide is entirely lacking in Echinoderms, Stomochordates and Chordates, with the remarkable exception of the peritrophic membrane in Tunicates. Chitin biosynthesis thus appears as a biochemical characteristic, which must be used with care when discussing the systematic position and phylogenetic relationships. [less ▲]

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See detailChitine et phylogénie : application d'une méthode enzymatique de dosage de la chitine
Jeuniaux, Charles ULg

in Bulletin de la Société de Chimie Biologique (1965), 47(12), 2267-2278

Using a purified preparation of chitinases, an enzymatic method for the specific detection and the quantitative measurement of chitin is described. This method allows the determination of the free chitin ... [more ▼]

Using a purified preparation of chitinases, an enzymatic method for the specific detection and the quantitative measurement of chitin is described. This method allows the determination of the free chitin and of the chitin bound to other substances, as in glycoproteic complexes. This method has been applied to the study of chitin distribution in the animal kingdom. On the basis of this survey, the evolution of chitin biosynthesis is discussed from the point of view of animal phylogeny. [less ▲]

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See detailChitinolytic enzymes of the gastric mucosa of Perodicticus Potto (Primate Prosimian) : purification and enzyme specificity
Cornelius, C.; Dandrifosse, Guy ULg; Jeuniaux, Charles ULg

in International Journal of Biochemistry (The) (1976), 7

1. Enzymatic extracts of Perodicticus potto gastric mucosa showed chitinolytic activity together with lysozymic activity. 2. After purification by adsortion on colloidal chitin and gel chromatography, an ... [more ▼]

1. Enzymatic extracts of Perodicticus potto gastric mucosa showed chitinolytic activity together with lysozymic activity. 2. After purification by adsortion on colloidal chitin and gel chromatography, an enzymatic preparation with high chitinolytic activity was devoid of any lysozymic activity. 3. The gastric chitinolytic enzymes of Perodicticus potto are thus "true" chitinases specific of the B-1,4-N-acetylglucosamine linkages in chitin molecule. [less ▲]

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See detailChitinoproteic complexes and mineralization in mollusk skeletal structures
Poulicek, Mathieu ULg; Voss-Foucart, M.F.; Jeuniaux, Charles ULg

in Muzzarelli, R.; Jeuniauc, Charles (Eds.) Chitin in nature and technology (1986)

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See detailChitinous Cuticle and Systematic Position of Tardigrada
Bussers, Jean-Claude ULg; Jeuniaux, Charles ULg

in Biochemical systematics (1973), 1

The chitinous nature of the cuticle, jaws and stomodaeum of three species of Tardigrada has been definitely proven using a specific micromethod involving a preparation of purified chitinase. These ... [more ▼]

The chitinous nature of the cuticle, jaws and stomodaeum of three species of Tardigrada has been definitely proven using a specific micromethod involving a preparation of purified chitinase. These chemical characteristics are in favour of the phylogenetic closeness between Tardigrada and the Arthropoda. [less ▲]

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See detailChitinous microfibres in the inner epicuticle of crab and myriapod sclerites
Compère, Philippe ULg; Schilito, Bruce; Gaill, Françoise et al

in Domard, Alain; Jeuniaux, Charles; Muzzarelli, Ricardo (Eds.) et al Advances in chitin sciences, volume I (1996)

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See detailChitinous structures
Jeuniaux, Charles ULg

in Florkin, Marcel; Stotz, Elmer H. (Eds.) Comprehensive biochemistry. Volume 26 Part C (1971)

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