Feasibility studies on enzymatic production of galacto-oligosaccharides from lactose and recovery of enzyme through ultrafiltration

摘要

The enzymatic membrane reactor consists of coupling of a membrane separation process with an enzymatic reaction. The enzymatic membrane recycle bioreactor consists of a reaction vessel, operated as a stirred tank reactor, coupled in a semi closed-loop configuration via a pump to a membrane module containing a semi-permeable membrane. The membrane is chosen to retain the enzyme and the product molecules are small enough to permeate through the membrane pores while the biocatalyst is recycled back to the reactor for further reaction. One important application of membrane reactors is the production of oligosaccharides. Galacto-oligosaccharides (GOS) are prebiotics produced by transgalactosylation reaction catalysed by β-galactosidase enzyme using lactose as substrate. A number of positive heath effects associated with the consumption of GOS include enhancement of calcium and magnesium absorption, assisting in inhibition of attachment of pathogenic bacteria to colonic epithelium, use as therapeutic agent in irritable bowel syndrome etc.