Production of thermostable invertases by Aspergillus caespitosus under submerged or solid state fermentation using agroindustrial residues as carbon source

• Autor(a) principal: Alegre,Ana Cláudia Paiva
• Data de Publicação: 2009
• Outros Autores: Polizeli,Maria de Lourdes Teixeira de Moraes, Terenzi,Héctor Francisco, Jorge,João Atílio, Guimarães,Luis Henrique Souza
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Brazilian Journal of Microbiology
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822009000300025
• topic: Aspergillus caespitosus; ²-D-fructofuranosidase; invertase; solid-state fermentation; submerged fermentation

The filamentous fungus Aspergillus caespitosus was a good producer of intracellular and extracellular invertases under submerged (SbmF) or solid-state fermentation (SSF), using agroindustrial residues, such as wheat bran, as carbon source. The production of extracellular enzyme under SSF at 30ºC, for 72h, was enhanced using SR salt solution (1:1, w/v) to humidify the substrate. The extracellular activity under SSF using wheat bran was around 5.5-fold higher than that obtained in SbmF (Khanna medium) with the same carbon source. However, the production of enzyme with wheat bran plus oat meal was 2.2-fold higher than wheat bran isolated. The enzymatic production was affected by supplementation with nitrogen and phosphate sources. The addition of glucose in SbmF and SSF promoted the decreasing of extracellular activity, but the intracellular form obtained in SbmF was enhanced 3-5-fold. The invertase produced in SSF exhibited optimum temperature at 50ºC while the extraand intracellular enzymes produced in SbmF exhibited maximal activities at 60ºC. All enzymatic forms exhibited maximal activities at pH 4.0-6.0 and were stable up to 1 hour at 50ºC.