Amylases encapsulated in organosilane-modified silicas prepared by sol-gel: evaluation of starch saccharification

摘要

A series of amylases were encapsulated within silica matrices taking into account the nature of the amylase: alpha-amylase (Bacillus subtilis), alpha-amylase (Aspergillus oryzae), and beta-amylase (barley), and the nature of the organosilane (alkyl-, amine- and mercaptan-based organosilanes). The results for the biocatalytic activity were shown to be dependent on the nature of the encapsulated enzymes and on the nature of the employed organosilane. Organosilanes containing the amine group showed different effects and lower biocatalytic conversions (on average). In general, beta-amylase increased in biocatalytic activity after encapsulation. There was a strong correlation between the nature of the organosilane and the resulting porosity of the matrix as well as the reducing sugars produced from the saccharification tests. The lower the particle radius of gyration and the higher degree ramification of the secondary particles, the higher the catalyst bioactivity was. Generally, glucose production during saccharification was favored by the encapsulation of the enzyme.