Production of lignocellulolytic enzymes by Aspergillus niger biofilms at variable water activities
Electron. j. biotechnol
;
10(1): 124-140, Jan. 2007. ilus, graf
Artigo
em Inglês
| LILACS
| ID: lil-460052
ABSTRACT
Lignocellulolytic enzyme production by Aspergillus niger was compared both in submerged fermentation (SF) and biofilm fermentation (BF) at varying water activities. Maximal filter paper activity, endoglucanase and xylanase activities were much higher in BF (2.96, 4.7 and 4.61 IU ml-1, respectively) than in SF cultures (1.71, 1.31 and 2.3 IU ml-1, respectively) but biomass yields were lower in BF than in SF (0.338 g g-1 and 0.431 g g-1, respectively). In the presence of 20 percent ethylene glycol (a w = 0.942) the enzyme activities decreased in both systems but BF still had higher levels (1.0, 1.0 and 2.6 IU ml-1, respectively) than SF cultures (0.6, 0.7 and 1.5 IU ml-1, respectively). An increase in xylanase specific activity of more than 2 fold (from 4.2 to 10.2 IU mg-1 biomass) was observed in the presence of 20 percent ethylene glycol, suggesting differential regulatory mechanisms in biofilm fermentation related to cell adhesion.
Texto completo:
DisponíveL
Índice:
LILACS (Américas)
Idioma:
Inglês
Revista:
Electron. j. biotechnol
Assunto da revista:
Biotecnologia
Ano de publicação:
2007
Tipo de documento:
Artigo
País de afiliação:
Peru
Instituição/País de afiliação:
Universidad Nacional Agraria La Molina/PE
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