Search Results - (Author, Cooperation:S. Couto)

2011-03-26

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

National Institutes of Health (U.S.)/*organization & administration ; Translational Medical Research/*organization & administration ; United States

2011-05-17

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Amino Acid Motifs ; Animals ; Carrier Proteins/metabolism ; Cell Line ; Cell Line, Tumor ; Cell Proliferation ; Cell Transformation, Neoplastic ; DNA-Binding Proteins/genetics/metabolism ; Humans ; Male ; Mice ; Nuclear Proteins/deficiency/*metabolism ; PTEN Phosphohydrolase/deficiency ; Prostatic Neoplasms/metabolism/pathology ; Protein Binding ; Proto-Oncogene Proteins c-ets/*metabolism ; Transcription Factors/genetics/metabolism ; Tumor Suppressor Proteins/*metabolism ; Ubiquitin-Protein Ligases/deficiency/genetics/*metabolism ; Ubiquitination

0178-515X

Springer Online Journal Archives 1860-2000

Process Engineering, Biotechnology, Nutrition Technology

Abstract   The production of ligninolytic enzymes by the fungus Phanerochaetechrysosporium BKM-F-1767 (ATCC 24725) in packed-bed tubular bioreactors, operating in semi-solid-state conditions, was studied. Three types of carriers were assayed: cubes of polyurethane foam, cubes of nylon sponge and chopped corncob, in order to determine the more suitable one to produce ligninolytic enzymes by this fungus. The cultivations were carried out in discontinuous and in continuous mode. For discontinuous cultivation, maximum individual manganese-dependent peroxidase (MnP) activities of 1593, 1371 and 346 U/l were achieved in the bioreactors filled with cubes of nylon sponge, cubes of polyurethane foam and with corncob, respectively. On the other hand, lignin peroxidase (LiP) activities about 100 U/l were found in the two former and around 200 U/l in the latter. Moreover, laccase, was detected in all cultures, with average values of 30 U/l. Nonetheless, continuous mode cultivation led to lower ligninolytic enzyme activities than those produced in discontinuous, except in the case of the corncob. Furthermore, the decolourisation of the dye Poly R-478 by the above-mentioned cultures was investigated. The percentage of biological decolourisation reached was about 70% in the bioreactor filled with cubes of nylon sponge whereas it was rather low in the others (around 30%).

Electronic Resource

0178-515X

Springer Online Journal Archives 1860-2000

Process Engineering, Biotechnology, Nutrition Technology

Abstract A factorial design at two levels was used to determine the effect of milk whey concentration and the addition of nitrogen (as NH4NO3) and phosphorus (as KH2PO4) on the oxalic acid production by Aspergillus niger. The results of the experiments indicated that milk whey contains enough nutrients for fungus growth, therefore medium supplementing with N and P is not necessary. The optimum milk whey concentration was 100 kg/m3 reaching a final oxalic acid concentration of 37 kg/m3 and a maximum production rate of 3.4 kg/m3 · d. The yield of oxalic acid was 0.4, a very high value compared to previous works.

Electronic Resource

1573-6776

immersion bioreactor ; LiP ; MnP ; Phanerochaete chrysosporium ; solid state fermentation

Springer Online Journal Archives 1860-2000

Process Engineering, Biotechnology, Nutrition Technology

Abstract The production of manganese-dependent peroxidase (MnP) and lignin peroxidase (LiP) by the fungus Phanerochaete chrysosporium (ATCC 24725) in a new bioreactor, the Immersion Bioreactor, which grows cells under solid-state conditions, was studied. Maximum MnP and LiP activities were 987 U l−1 and 356 U l−1, respectively. The polymeric dye, Poly R-478, was degraded at 2.4 mg l−1 min−1 using the extracellular culture filtrate.

Electronic Resource

0138-4988

Life Sciences ; Life Sciences (general)

Wiley InterScience Backfile Collection 1832-2000

Process Engineering, Biotechnology, Nutrition Technology

In this paper, the in vivo decolourization of the polymeric dye Poly R-478 by semi-solid-state cultures of Phanerochaete chrysosporium BKM-F-1767 (ATCC 24725) was investigated, employing corncob as a support. In order to stimulate the ligninolytic system of the fungus, the cultures were supplemented with veratryl alcohol (2 mM) or manganese (IV) oxide (1 g/l).Maximum manganese-dependent peroxidase (MnP) and lignin peroxidase (LiP) activities of around 2,000 U/l and 400 U/l were attained by the former, whereas the activities reached by the latter were of about 1,500 U/l and 200 U/l, respectively. Furthermore, laccase activity (around 150 U/l) was only detected in manganese (IV) oxide supplemented cultures.The polymeric dye Poly R-478 (0.02 w/v) was added to three-day-old cultures. A percentage of biological decolourization of about 85% was achieved using cultures supplemented with veratryl alcohol, whereas MnO2 cultures showed a rather lower percentage of around 58% after nine days of dye incubation. Moreover, a correlation between MnP activity and Poly R-478 decolourization could be observed, indicating that this enzyme is mainly responsible for dye degradation.In the present work, the in vivo decolourizing capability of the ligninolytic complex secreted by P. chrysosporium was investigated under the above-mentioned cultivation conditions, employing a model compound, such as the polymeric dye Poly R-478.

2 Ill.

Electronic Resource

0138-4988

Life Sciences ; Life Sciences (general)

Wiley InterScience Backfile Collection 1832-2000

Process Engineering, Biotechnology, Nutrition Technology

The effects of adding some inducers of lignolytic activity to semi-solid-state cultures of Phanerochaete chrysosporium BKM-F-1767 (ATCC 24725) were investigated. The inducers assayed were veratryl alcohol and solid manganese (IV) oxide. The microorganism was cultured on corncob, which functioned both as physical support and source of nutrients.Supplementing the cultures with veratryl alcohol created the situation where manganese-dependent peroxidase (MnP) and lignin peroxidase (LiP) activities of approximately 1,500 U/l and 200 U/l, respectively, could be attained. These activities were considerably higher than those obtained in the reference cultures (about 5 and 4-fold).In the same way, the addition of manganese (IV) oxide led to MnP and LiP activity levels of about 2,000 U/l and 300 U/l, respectively. These activities were also notably above (about 6 and 5-fold, respectively) those achieved in the reference cultures.Moreover, laccase activity (around 200 U/l) was only detected in veratryl alcohol or manganese (IV) oxide supplemented cultures.

1 Ill.

Electronic Resource