Purification and properties of exo-imulinases from Penicillium janczewskii growing on distinct carbon sources

Autor(es)

Pessoni, Rosemeire A. B. ; Braga, Marcia R. ^[2] ; Figueiredo-Ribeiro, Rita de Cássia L.

• Tipo de documento: Artigo Científico
• Fonte: Mycologia; v. 99, n. 4, p. 493-503, July 2007.
• Área do conhecimento: Ciências Biológicas - Botânica
• Assunto(s): Enzimas Sacarose Inulina Fungos Penicillium

Resumo

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)

• Processo FAPESP: 05/04139-7 - Carboidratos de plantas tropicais como moduladores de processos ecofisiológicos e indicadores de respostas a estresses ambientais
• Beneficiário: Marcia Regina Braga
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 98/05124-8 - Conservação e uso sustentável da biodiversidade vegetal do Cerrado e da Mata Atlântica: o armazenamento de carboidratos e seu papel na adaptação e manutenção de plantas em seu habitat natural
• Beneficiário: Marcos Silveira Buckeridge
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOTA - Temático