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Enzymatic synthesis of Tinuvin
Schroeder, M.; Pereira, Luciana; Rodríguez Couto, S.; Erlacher, Angelika; Schoening, K.-U.; Paulo, Artur Cavaco; Guebitz, G. M.Coupling of 3-(3-tert-butyl-4-hydroxyphenyl) propionic acid methylester to 1H-benzotriazole using a laccase from Trametes hirsuta was studied. The potentially resulting coupling product Tinuvin 1130 is an important UV-absorber used in polymer based materials. Oxidation of the phenol by the laccase led to homomolecular coupling reactions while the laccase did not attack 1H-benzotriazole. Due to the homomolecular...
A new cuticle scale hydrolysing protease from beauveria brongniartii
Erlacher, Angelika; Sousa, Fernanda; Schroeder, M.; Jus, S.; Kokol, V.; Paulo, Artur Cavaco; Gübitz, Georg M.From a screening for the production of new proteases specific for cuticle scales, Beauveria brongniartii was selected producing an alkaline Ca++ dependent protease. The purified had a molecular weight of 27 kDa and a pI value of 8.0. Substrate specificities of model substrates (wool with partially removed cuticles treated with SDS) were analyzed by protein release, dissolved organic carbon (DOC) and nitrogen an...
Detergent formulations for wool domestic washings containing immobilized enzymes
Vasconcelos, Andreia; Silva, Carla J. S. M.; Schroeder, M.; Gübitz, Georg M.; Paulo, Artur CavacoThe stability of immobilized and native Esperase, a commercial serine protease, was studied by incubating the enzymes in four formulations containing the same amount of anionic and non-ionic surfactants. The results show that the activity of the immobilized enzyme is not affected by the presence of detergents while the native enzyme lost 50% of activity after 20 min of incubation in these four formulations. The...
Specificities of a chemically modified laccase from trametes
Schroeder, M.; Heumann, Sonja; Silva, Carla J. S. M.; Paulo, Artur Cavaco; Gübitz, Georg M.Laccases could prevent fabrics and garments from re-deposition of dyes during washing and finishing processes by degrading the solubilized dye. However, laccase action must be restricted to solubilized dye molecules thereby avoiding decolorization of fabrics. Chemical modification of enzymes can provide a powerful tool to change the adsorption behaviour of enzymes on water insoluble polymers. Polyethylene glyco...
New enzyme based process direction to prevent wool shrinking without substantia...
Lenting, H.; Schroeder, M.; Gübitz, Georg M.; Paulo, Artur CavacoIn this paper a new enzymatic process direction is described for obtaining machine washable wool with acceptable quality. In general, application of protease enzyme technology in wool processing results in considerable loss of tensile strength by diffusion of the enzyme into the interior of wool fibers. To overcome this disadvantage enzymatic activity has been more targeted to the outer surface of the scales by...
Restricting detergent protease action to surface of protein fibres by chemical ...
Schroeder, M.; Lenting, H.; Kandelbauer, A.; Silva, Carla J. S. M.; Paulo, Artur Cavaco; Gübitz, Georg M.Due to their excellent properties, such as thermostability, activity over a broad range of pH and efficient stain removal, proteases from Bacillus sp. are commonly used in the textile industry including industrial processes and laundry and represent one of the most important groups of enzymes. However, due to the action of proteases, severe damage on natural protein fibres such as silk and wool result after was...
Biotransformation of phenolics with laccase containing bacterial spores
Held, C.; Kandelbauer, A.; Schroeder, M.; Paulo, Artur Cavaco; Gübitz, Georg M.Treatment of effluents containing phenols such as textile dyes with fungal laccases is usually limited to the acid to neutral pH range and moderate temperatures. Here we demonstrate for the first time that spore-bound laccases which are stable at high temperatures and pH values can be used for phenolic dye decolorisation. Laccase containing spores from Bacillus SF were immobilized on alumina pellets. Both immob...
Biotransformation of phenolics with laccase containing bacterial spores
Held, C.; Kandelbauer, A.; Schroeder, M.; Paulo, Artur Cavaco; Gübitz, Georg M.Treatment of effluents containing phenols such as textile dyes with fungal laccases is usually limited to the acid to neutral pH range and moderate temperatures. Here we demonstrate for the first time that spore-bound laccases which are stable at high temperatures and pH values can be used for phenolic dye decolorisation. Laccase containing spores from Bacillus SF were immobilized on alumina pellets. Both immob...
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