PRODUCTION AND APPLICATION OF AN ISOAMYLASE FROM FLAVOBACTERIUM-ODORATUM

A strain of Flavobacterium capable of producing an extracellular therm ostable isoamylase which grew with optima at pH 6.0 and 30 degrees C w as isolated from soil. Maximum enzyme production was observed with the medium (pH 5.3) composed of 3% (w/v) soluble starch, 3% soybean prote in, 0.01% Na hydrogen L-glutamate, 0.14% KH2PO4, 0.02% MgSO4 . 7H(2)O, and 0.01% CaCl2 . 2H(2)O after 48 h of cultivation at 30 degrees C un der aerobic conditions. The thermal stability of the enzyme in the pre sence of Ca2+ increased remarkably with trehalose and maltooligosaccha rides. Maltotriose and maltotetraose were the most effective for stabi lization against heating. Although a higher yield of condensed product s was obtained with larger saccharides, the condensation of various li near maltooligosaccharides by the enzyme was significantly lower than that by the Pseudomonas isoamylase, and no condensed products were for med from trehalose by either enzyme. Addition of the Flavobacterium is oamylase remarkably enhanced the production of maltose, maltotroise, m altoteraose, and trehalose under industrial conditions for starch proc essing in the presence of respective auxiliary enzymes because of its lower transfer and condensation actions when compared with those of th e Klebsiella pullulanase. These enzymatic characteristics are consiste nt with the industrial production of various saccharides from starch.