Cellulolytic enzymes from sheep-rumen liquor micro-organisms

Abstract

Cell-free ex-tracts of sheep-rumen microorganisms were used to study the hydrolysis of cellobiose and sodium carboxymethylcellulose, by determination of the reducing sugar liberated. Controlled inhibition studies with gluconolactone showed cellobiase to be completely inhibited by 2.5 mM. lactone, for concentrations of cellobiose up to 5% (w/v). Inhibition of hydrolysis of sodium carboxymethylcellulose reaches a constant value of 60% at a lactone concentration where cellobiase is completely inhibited. Chromatographic analysis of cellobiose hydrolysates revealed that transferase activity is barely detectable in 0.2% cellobiose solutions, but becomes appreciable in 5% cellobiose, and that 3 oligosaccharides were formed. Transferase activity is inhibited by gluconolactone. Chromatographic analysis of sodium carboxymethylcellulose hydrolysates showed glucose to be the predominant product, along with traces of cellobiose, and possibly xylose. In the presence of gluconolactone, production of glucose is almost completely inhibited and the amounts of cellobiose are sometimes slightly increased; a small amount of a substance which may be cellopentose was detected with a silver nitrate reagent.