| Full text | |
| Author(s): |
Pessoni, Rosemeire A. B.
;
Braga, Marcia R.
[2]
;
Figueiredo-Ribeiro, Rita de Cássia L.
Total Authors: 3
|
| Document type: | Journal article |
| Source: | Mycologia; v. 99, n. 4, p. 493-503, July 2007. |
| Field of knowledge: | Biological Sciences - Botany |
| Abstract | |
Penicillium janczewskii, isolated from the rhizosphere of Vernonia herbacea, grows rapidly on media containing either sucrose or inulin, although inulin more than sucrose induced the production of inulinases. Three different extracellular ß-fructofuranosidases (two inulinases and one invertase) were purified from fungal cultures grown on sucrose or inulin, through precipitation with ammonium sulfate, and anion-exchange, hydrophobic interaction and gel filtration chromatographies. The optimum temperature of the three enzymes was approximately 60 C, optimum pH 4–5.5 and apparent molecular mass of 80 kDa. Km and Vmax values determined for invertase on sucrose were respectively 3.7 10–4 M and 7.9 10–2 µmol/min/mL, and on inulin 6.3 10–2 M and 2.09 10–2 µmol/min/mL. The values of km for the two inulinases were 8.11 10–4 and 2.62 10–3 M, being lower for inulin when compared to those obtained for sucrose. The inulinases did not produce oligofructans from inulin, indicating they are primarily exoinulinases. The differences found in inulinase induction patterns when inulin or sucrose was used seem to be related to modifications on the enzyme properties, mainly concerning substrate affinity. (AU) | |
| FAPESP's process: | 05/04139-7 - Carbohydrates of tropical species as modulators of ecophysiological processes and as environmental stress response markers |
| Grantee: | Marcia Regina Braga |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 98/05124-8 - Conservation and sustainable use of the plant biodiversity from the cerrado and Atlantic Forest: the storage of carbohydrates and their role on the adaptation and maintainance of plants in their natural environment |
| Grantee: | Marcos Silveira Buckeridge |
| Support Opportunities: | BIOTA-FAPESP Program - Thematic Grants |