| Journal: | Brazilian archives of biology and technology |
| Database: | PERIÓDICA |
| System number: | 000392684 |
| ISSN: | 1516-8913 |
| Authors: | Nahas, Ely1 |
| Institutions: | 1Universidade Estadual Paulista "Julio de Mesquita Filho", Faculdade de Ciencias Agrarias e Veterinarias, Jaboticabal, Sao Paulo. Brasil |
| Year: | 2015 |
| Season: | Sep-Oct |
| Volumen: | 58 |
| Number: | 5 |
| Pages: | 658-666 |
| Country: | Brasil |
| Language: | Inglés |
| Document type: | Artículo |
| Approach: | Analítico, descriptivo |
| English abstract | This work studied the acid phosphatase (APase) activity from culture medium (extracellular, eAPase) and mycelial extract (intracellular, iAPase) of Aspergillus niger F111 . The influence of fungus growth and phosphate concentration of the media on the synthesi s and secretion of phosphatase was demonstrated. The effects of pH, substrate concentration and inorganic and organic compounds added to the reaction mixture on APase activity were also studied. Both enzymes were repressed by high concentrations of phospha te. Overexpression of iAPase in relation to eAPase was detected; iAPase activity was 46.1 times higher than eAPase. The maximal activity of eAPase was after 24h of fungus growth and for iAPase was after 96h. Optimal pH and substrate concentrations were 4.5 and 8.0 mM, respectively. Michaelis – Menten constant ( K m) for the hydrolysis of p - nitrophenyl phosphate was 0.57 mM with V max = 14,285.71 U mg - 1 mycelium for the iAPase and 0.31 mM with V max = 147.06 U mg - 1 mycelium for eAPase. Organic substances had littl e effect on acid phosphatases when compared with the salts. Both the APases were inhibited by 10 mM KH 2 PO 4 and 5 mM (NH 4 ) 2 MoO 4 ; eAPase was also inhibited by 1 mM CoCl 2 |
| Disciplines: | Química, Biología, Agrociencias |
| Keyword: | Bioquímica, Hongos, Suelos, Inhibidores, Enzimas, Molibdeno, Propiedades químicas, Fosfatos |
| Keyword: | Chemistry, Biology, Agricultural sciences, Biochemistry, Fungi, Soils, Inhibitors, Enzymes, Molybdenum, Chemical properties, Phosphate |
| Full text: | Texto completo (Ver PDF) |
