Detection of Marine Alginolytic Bacteria

Abstract

IN the examination of the hydrolases of algal polysaccharides in marine bacteria, a simple method to detect alginase is desirable¹. A difficulty arises in the preparation of media because of the precipitation of alginate by the divalent ions in sea-water. The methods previously described were reviewed by Thjøtta and Kåss². The disadvantages of these methods are that the measurement of decrease in viscosity of an alginate broth requires a special apparatus², and the alginate agar medium of Waksman et al.³ cannot be used for marine strains which liquefy agar. The preferred method is one based on the liquefaction of an alginate gel. A simple method for the formation of this gel in a sea-water medium is described here. The alginate gel is formed by the slow diffusion of divalent ions from a sea-water agar medium into a solution of sodium alginate. This method is similar to the double-layer technique for the preparation of a pectate gel⁴.