Consulta: subjectFacets:"Polyurethane foam"
Registros recuperados: 3
Data/hora: 01/06/2024 02:06:36

A comparison of methods to determine tannin acyl hydrolase activity
Provedor de dados: 52
Autores: Aguilar,Cristóbal; Christopher,Augur; Viniegra-González,Gustavo; Favela,Ernesto.
Six methods to determine the activity of tannase produced by Aspergillus niger Aa-20 on polyurethane foam by solid state fermentation, which included two titrimetric techniques, three spectrophotometric methods and one HPLC assay were tested and compared. All methods assayed enabled the measurement of extracellular tannase activity. However, only five were useful to evaluate intracellular tannase activity. Studies on the effect of pH on tannase extraction demonstrated that tannase activity was considerably under-estimated when its extraction was carried out at pH values below 5.5 and above 6.0. Results showed that the HPLC technique and the modified Bajpai and Patil methods presented several advantages in comparison to the other methods tested.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Tannin acyl hydrolase; Assay; Polyurethane foam; Solid state fermentation; Tannase.
Ano: 1999
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89131999000300014

Morphological study of biomass during the start-up period of a fixed-bed anaerobic reactor treating domestic sewage
Provedor de dados: 52
Autores: Lima,Cláudio Antonio Andrade; Ribeiro,Rogers; Foresti,Eugenio; Zaiat,Marcelo.
This work focused on a morphological study of the microorganisms attached to polyurethane foam matrices in a horizontal-flow anaerobic immobilized biomass (HAIB) reactor treating domestic sewage. The experiments consisted of monitoring the biomass colonization process of foam matrices in terms of the amount of retained biomass and the morphological characteristics of the cells attached to the support during the start-up period. Non-fluorescent rods and cocci were found to predominate in the process of attachment to the polyurethane foam surface. From the 10th week of operation onwards, an increase was observed in the morphological diversity, mainly due to rods, cocci, and Methanosaeta-like archaeal cells. Hydrodynamic problems, such as bed clogging and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Anaerobic digestion; Biofilm; Domestic sewage; Fixed-bed reactor; Polyurethane foam.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132005000600020

Biodegradation of cypermethrin by immobilized cells of Micrococcus sp. strain CPN 1
Provedor de dados: 58
Autores: Tallur,Preeti N.; Mulla,Sikandar I.; Megadi,Veena B.; Talwar,Manjunatha P.; Ninnekar,Harichandra Z.
Pyrethroid pesticide cypermethrin is a environmental pollutant because of its widespread use, toxicity and persistence. Biodegradation of such chemicals by microorganisms may provide an cost-effective method for their detoxification. We have investigated the degradation of cypermethrin by immobilized cells of Micrococcus sp. strain CPN 1 in various matrices such as, polyurethane foam (PUF), polyacrylamide, sodium alginate and agar. The optimum temperature and pH for the degradation of cypermethrin by immobilized cells of Micrococcus sp. were found to be 30 °C and 7.0, respectively. The rate of degradation of 10 and 20 mM of cypermethrin by freely suspended cells were compared with that of immobilized cells in batches and semi-continuous with shaken...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Degradation; Immobilization; Cypermethrin; Polyurethane foam; Micrococcus sp. strain CPN 1.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822015000300667