Abstract
In industrial fermentation of L-glutamic acid with cane molasses as the main carbon source, productivity increased when sucrose inversion was done first. Sucrose could be hydrolyzed by yeast invertase immobilized in alginate. As a first step, a pilot-scale apparatus was tried. Na-alginate that contained invertase was pressed out, gelled with a Ca2+ solution, and then cut to give cylindrical particles with immobilized enzyme. Optimum conditions were investigated. The length of particles with immobilized enzyme was proportional to the flow rate of Na-alginate and inversely proportional to the speed at which the cutting blades revolved. A speed of revolution less than the critical value (600 rpm, for this apparatus) gave highly stable production. Room temperature was suitable and cane molasses could be used for gelling. A flow rate of 80l/h and a speed of revolution of 500 rpm gave particles with immobilized enzyme 4mm long with a diameter of 1.4mm. The immobilized enzyme had the same activity as the enzyme prepared on the laboratory scale and it retained activity for at least 30 days during a performance test.
