In this work, novel nanoflower/alginate microbeads were synthesized to immobilize alpha-acetolactate decarboxylase (ALDC) with a facile approach. Typically, ALDC was first coprecipitated with Ca-3(PO4)(2) to form enzyme inorganic hybrid nanoflowers (Ca-3(PO4)(2)-ALDC), and then the nanoflowers containing micrometre-sized particles and nanoscale flower-like petals were entrapped in alginate gel beads (Ca-3(PO4)(2)-ALDC)@Mg). Compared with free ALDC and Ca-3(PO4)(2)-ALDC nanoflowers, the microbeads performed greatly improved recyclability and stability, meanwhile, retained 98% of activity compared with free ALDC. Moreover, the immobilized enzyme can be used in a 300 L beer fermentation tank to prevent the formation of diacetyl, solve the problem of beer off-flavor and short the beer maturation time, thus exhibiting a great potential application in beer brewing industry.