INTRACELLULAR ALGINATE-OLIGOSACCHARIDE DEGRADING ENZYME-ACTIVITY THATIS INCAPABLE OF DEGRADING INTACT SODIUM ALGINATE FROM A MARINE BACTERIUM ALTEROMONAS SP

Intracellular homo-and hetero-polymeric blocks degrading enzyme activi ty incapable of degrading intact sodium alginate was detected in Alter omonas sp. strain H-4. The enzyme activity for polyM and MG blocks was highest during the late log phase of the bacterium and was not induce d by the addition of sodium alginate to the culture medium. The activi ty for MG random block was as high as that for polyM, but that for pol yG block was half and that for sodium alginate was one fifth. At least 4 kinds of enzyme activities, a polyM specific, a MG-polyM specific, and two kinds of polyG specific enzymes, were detected from the crude intracellular fraction, but a trace spot for sodium alginate. Analysis of reaction products using a partially purified preparation of the en zyme indicated that the enzyme generated a saturated diuronate and an unsaturated polyuronide from polyM block. These results suggest that t he intracellular enzymes can degrade only oligosaccharides generated f rom high molecular alginate by the extracellular alginate lyase and ma y have an important role in the alginate metabolism of the bacterium.