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Optimization of cellulase production by a versatile Aspergillus fumigatus fresenius strain (AMA) capable of efficient deinking and enzymatic hydrolysis of Solka floc and bagasse

Author:
Soni, Rohit, Nazir, Asiya, Chadha, B.S.
Source:
Industrial crops and products 2010 v.31 no.2 pp. 277-283
ISSN:
0926-6690
Subject:
Aspergillus fumigatus, cellulases, bioreactors, optimization, biosynthesis, deinking, pollution control, functional properties, enzymatic hydrolysis, bagasse, waste treatment, saccharification, cellulose, yields, enzymes, enzyme activity, paper pulp, paper, endo-1,4-beta-glucanase, cellulose 1,4-beta-cellobiosidase, beta-glucosidase, xylanases, biofuels
Abstract:
This study reports the optimization of cellulase production by a versatile Aspergillus fumigatus fresenius (AMA) strain capable of efficient deinking and enzymatic hydrolysis of Solka floc and bagasse. The culture produced maximal levels of cellulase on basal salt medium containing rice straw as carbon and beef extract as nitrogen source at 45°C. Further optimization of enzyme production was carried out using Box-Behnken design of experiment to study the influence of process variables (beef extract, temperature and tween 80) on cellulase and xylanase production. The model computed for R ² value ranged between 95.3% and 99.9% indicating that they are appropriate and can be useful to predict the level of beef extract, temperature and tween 80 required to achieve optimal cellulase production by A. fumigatus fresenius (AMA). The culture under optimized conditions produced 240.2, 9.73, 470, 15, 2800 (units/g of substrate) of endoglucanase, Fpase, β-glucosidase, cellobiohydrolase (CBH) and xylanase corresponding to 2.45, 2.88, 2.13 and 1.29 folds improvement, respectively, in enzyme activities when compared to those obtained under unoptimized conditions. The treatment of composite paper pulp with enzyme extracts (@ 0.5U CMCase/g pulp) for 30min resulted in 53% removal of ink and increased the brightness of the hand sheets by 4.32% ISO. The concentrated culture extracts from A. fumigatus fresenius also efficiently hydrolyzed Solka floc SW 40 and bagasse (@ 7%, w/v) resulting in 90 and 87% saccharification, respectively.
Agid:
778098