Immobilization of thermostable maltogenic amylase from Bacillus stearothermophilus for continuous production of branched oligosaccharides.

摘要

A new thermostable maltogenic amylase isolated from Bacillus stearothermophilus (BSMA) was immobilized and characterized for continuous production of branched oligosaccharides (BOS). Immobilized BSMA had characteristics similar to those of the freeform, apart from better stability with regard to temperature and metal ions. Optimum conditions for continuous production of BOS using a packed bed column reactor of immobilized BSMA were: substrate concentration 20% and flow rate 11 ml/h. As the substrate concentration or flow rate increased, the content of sugars having higher MW generally increased and vice versa, suggesting the possibility of controlling the composition of BOS by adjusting these 2 factors. The yield of BOS from a continuous processwas maintained at 50% for up to 20 days and gradually decreased to 40% over 37 days. About 93% high-purity BOS was obtained after fermentation with yeast to remove glucose and maltose.