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1.
Int J Biol Macromol ; 48(5): 736-41, 2011 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-21382401

RESUMO

Acetic acid soluble material (AcSM) is a chitosan-rich fraction isolated from the fungal cell wall materials. The final step in the traditional production of fungal chitosan is the separation of chitosan from the cell wall AcSM via raising the pH to 9-10 followed by centrifugation. This step results in further undesirable economic and environmental effects. The goal of this paper is to avoid that by investigating the antimicrobial effect of the whole AcSM from Mucor rouxii DSM-1191 cell wall and its application on cotton fabrics. The treated fabrics were characterized through monitoring the textile physical properties and for the antibacterial activity against Escherichia coli and Micrococcus luteus. Results showed that Mucor rouxii DSM-1191 has excellent potentials to be used for cell wall AcSM production on industrial scale with a maximum content of 40% in dry mycelia. The obtained results indicated that the physical properties of the treated fabrics, as well as the antibacterial activity, were improved after treatment with fungal AcSM.


Assuntos
Ácido Acético/química , Antibacterianos/farmacologia , Quitosana/farmacologia , Mucor/química , Têxteis/microbiologia , Quitosana/isolamento & purificação , Escherichia coli/efeitos dos fármacos , Micrococcus luteus/efeitos dos fármacos , Solubilidade
2.
Int J Biol Macromol ; 47(4): 454-7, 2010 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-20603144

RESUMO

The anticandidal activity of four fungal chitosan types, produced from Mucor rouxii DSM-1191, against three Candida albicans strains was determined. The most bioactive chitosan type, to inhibit C. albicans growth, had the lowest molecular weight (32 kDa) and the highest deacetylation degree (94%). Water soluble types had stronger anticandidal activity than soluble types in 1% acetic acid solution. Scanning electron micrographs of treated C. albicans with fungal chitosan proved that chitosan principally interact with yeast cell wall, causing severe swelling and asymmetric rough shapes, and subsequent cell wall lyses with the prolonging of exposure time. Fungal chitosan could be recommended for C. albicans control as a powerful and safe alternative to synthetic and chemical fungicides.


Assuntos
Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Quitosana/farmacologia , Mucor/química , Animais , Candida albicans/ultraestrutura , Galinhas , Quitosana/química , Humanos , Testes de Sensibilidade Microbiana
3.
Int J Biol Macromol ; 47(1): 10-4, 2010 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-20416334

RESUMO

Four fungal chitosan types (CTS) were prepared from Mucor rouxii DSM 1191 and examined for their physico-chemical characteristics. The antimicrobial activity of chitosan types against 11 bacterial strains, including six pathogens, was investigated and the most effective type was chitosan No. 3 which was characterized with the lowest viscosity and molecular weight (3.1 cP and 2.1 x 10(4)Da, respectively), the highest degree of deacetylation (95%) and neutral water solubility. Gram positive bacteria were generally more sensitive to chitosan antimicrobial action than Gram negative strains and this action was notably affected by the environmental growth conditions, i.e. incubation temperature and pH value. The applications of fungal chitosan for the suppression of bacterial pathogens as a natural alternative, reduced risk and biodegradable biocidal agent could be recommended.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Quitosana/química , Quitosana/farmacologia , Bactérias Gram-Negativas/crescimento & desenvolvimento , Bactérias Gram-Positivas/crescimento & desenvolvimento , Mucor/química , Anti-Infecciosos/isolamento & purificação , Quitosana/isolamento & purificação , Bactérias Gram-Negativas/patogenicidade , Bactérias Gram-Positivas/patogenicidade
4.
Talanta ; 76(5): 1136-40, 2008 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-18761167

RESUMO

A comprehensive collection of wet-chemical analyses of functional groups on oxidatively treated surfaces of hydrophobic polymers like poly(ethylene terephthalate) or polyolefine is presented. New methods are introduced. Textiles and foils have been subjected to advanced oxidation processes and the different oxygen functions have been quantified. Analysis of surface functional groups includes radical site determination with radical scavengers like diphenylpicrylhydrazyl, reduction of peroxides determined iodometrically, cationic dyestuff adsorption, carbonyl binding to Girard reagent P and surface hydroxyl group determination by surface nitrosation and subsequent azo-dye formation photometrically determinable. Use of potential surface swelling agents has been excluded except for addition of wetting agent. Wet-chemical analyses on textile surfaces bear the benefit of integrating over (relatively) large sample areas, a point which is interesting when regarding inhomogenities of textile or other surface constructions. In addition examples for visualisation for the existence of surface groups are described.

6.
Biotechnol J ; 2(3): 347-52, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17285675

RESUMO

The enzyme catalase (EC 1.11.1.6) was covalently immobilized on textile carrier fabrics made of poly(ethylene terephthalate) (PET) by a novel combined wet chemical and photochemical process. The functionalization of catalase with allyl groups succeeds in a wet chemical treatment of the enzyme with allylglycidylether. This modified enzyme was bonded covalently to the textile material by a photochemical immobilization using a monochromatic excimer UV lamp (222 nm). Using this two-step procedure nearly 60 mg enzyme/g carrier could be fixed durably. The efficiency of the immobilization products was investigated by measuring the enzymatic decomposition of hydrogen peroxide in comparison to the free enzyme. The relative activity of the catalase after the immobilization was nearly 5% compared to the free, not fixed enzyme; however, even after 30 reuses, the modified and immobilized catalase still showed a distinct activity.


Assuntos
Catalase/metabolismo , Enzimas Imobilizadas/metabolismo , Polietilenoglicóis/química , Catalase/química , Enzimas Imobilizadas/química , Peróxido de Hidrogênio/metabolismo , Microscopia Eletrônica de Varredura , Fotoquímica/métodos , Poliésteres/química , Polietilenotereftalatos , Têxteis/análise , Têxteis/efeitos da radiação , Raios Ultravioleta
7.
Int J Pharm ; 311(1-2): 113-21, 2006 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-16442247

RESUMO

To determine the in vitro susceptibility of fungal organisms to beta-cyclodextrin (CD) complexes with the antifungal agents econazole-nitrate (EC) and ciclopirox-olamine (CI), a fast, rapid and simple method using laser nephelometry in 96-microtiter plate is used. The antimycotic influence of the complexes against Candida albicans DSM 11225 and Candida krusei ATCC 6258 species was determined using this method. A rapid inhibition and even killing of both fungi was observed only above certain concentrations of complex ranged between 12.5 and 100 microg/ml for beta-CD-econazole complex (CD-EC), while for the complex with ciclopirox-olamine (CD-CI) the range was between 150 and 400 microg/ml. The stability constants of the CD complexes with the two antimycotic derivatives are given. In addition, the nephelometric method allows the determination of solubilities of active agents. Thus, the improvement of solubility of both antimycotic agents in PBS buffer solution was observed by complexation with CD.


Assuntos
Antifúngicos/farmacologia , Excipientes/química , Lasers , Testes de Sensibilidade Microbiana , Microquímica , Nefelometria e Turbidimetria/métodos , beta-Ciclodextrinas/química , Antifúngicos/química , Varredura Diferencial de Calorimetria , Candida albicans/efeitos dos fármacos , Candida albicans/crescimento & desenvolvimento , Candida albicans/metabolismo , Química Farmacêutica , Ciclopirox , Estabilidade de Medicamentos , Econazol/química , Econazol/farmacologia , Corantes Fluorescentes , Piridonas/química , Piridonas/farmacologia , Solubilidade
8.
Anal Bioanal Chem ; 380(7-8): 937-41, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15536546

RESUMO

A new, sensitive assay for the quantitative determination of immobilized metal containing enzymes has been developed using atomic absorption spectroscopy (AAS). In contrast with conventionally used indirect methods the described quantitative AAS assay for metalloenzymes allows more exact analyses, because the carrier material with the enzyme is investigated directly. As an example, the validity and reliability of the method was examined by fixing the iron-containing enzyme catalase on cotton fabrics using different immobilization techniques. Sample preparation was carried out by dissolving the loaded fabrics in sulfuric acid before oxidising the residues with hydrogen peroxide. The iron concentrations were determined by flame atomic absorption spectrometry after calibration of the spectrometer with solutions of the free enzyme at different concentrations.


Assuntos
Catalase/análise , Enzimas Imobilizadas/análise , Enzimas Imobilizadas/química , Ferro/análise , Espectrofotometria Atômica/métodos , Catalase/química , Fibra de Algodão , Ferro/química , Modelos Lineares
9.
J Cosmet Sci ; 53(3): 185-91, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12053209

RESUMO

Cyclodextrins are non-toxic cyclic polysaccharides. They form inlusion complexes with numerous organic molecules. The physical and chemical properties of the guest molecules change due to complex formation. Thus, for example, the stability of the complexed molecule against light and oxygen increases and the vapor pressure is reduced. The solubility of slightly soluble molecules increases in a cyclodextrin complex. All these and further advantages of cyclodextrins and their complexes can be used for the formulation of cosmetic products. As a result, effects are possible not realizable with common techniques.


Assuntos
Cosméticos , Ciclodextrinas
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