Hydrolytic enzyme production in solid-state fermentation by Aspergillus niger 3T5B8

A mixture containing polygalacturonase, cellulase, xylanase and protease enzymes was produced using Aspergillus niger 3T5B8 on different agroindustrial residues by solid-state fermentation and tested for vegetable oil extraction. The enzymic activities were evaluated using second-order empirical models from experimental data as a function of fermentation time and cellobiose concentration in the fermentation medium. The use of wheat bran as substrate without cellobiose addition and 42 h of fermentation were the most favourable conditions for producing the mixture of hydrolytic enzymes (polygalacturonase 30.75 U/ml, xylanase 30.62 U/ml, protease 5.27 U/ml). Another favourable condition was obtained when mango peel was used as substrate in the presence of 0.2% cellobiose and 24 h of fermentation (FPCAse 3.5 U/ml, xylanase 20.33 U/ml). Enzymic formulations with suitable polygalacturonase and FPCAse activities were favourable to extract oil from the pulp of tropical fruits and oleaginous seeds. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.