Pullulanase properties

This paper will review our studies on 1) B-amylase of C. thermosulfUrogenes 2) a-glucosidase of C. thermohydrosulfuricum 3) glucose isomerase of C. thermosulfurogenes and Thermoanaerohacter strain B6A and, 4) endoxylanase of Thermoanaerohacter strain B6A. A separate paper by Saha et al., in this symposium, will report on the properties of the novel pullulanase present in these thermoanaerobes. 

Pullulanase Enzyme degrading pnUnlan, a branched starch pullulanase catalyzes the hydrolysis of the a-l,6-glncosidic linkage in a-glucans. Pullulanase preferentially hydrolyzes pnUnlan while isoamylase has a preference for glycogen and amylopectin. See WaUenfels, K Bender, H and Rached, J.R., Pnllnlanase from Aerobacter aerogenes production in a cell-bound state. Pnrification and properties of the enzymes, Biochem. Biophys. Res. 

An extracellular form and a cell-bound form of pullulanase (mol. wts. 1.26 x 10 and 1.41 x 10 , respectively) from Klebsiella aerogenes have been purified by ion-exchange chromatography, gel filtration, and affinity chromatography. The cell-bound form was also released by proteolysis. Comparisons of their physicochemical properties and amino-acid compositions suggested that the enzymes are derived from the same gene product, which can be cleaved selectively by endogenous or added proteases. 

The number and length of the outer chains of amylopectin have been altered by partial debranching with pullulanase and re-synthesis with potato phos-phorylase. Star-shaped molecules possessing similar properties have also been obtained by the action of muscle phosphorylase on intact amylopectin. 

Some properties of crystalline extracellular pullulanase from Aerobacter aerogenes were compared with those of crystalline intracellular pullulanase. The amino-acid compositions of these enzymes were found to be alike on the... 

Biosynthesis and Properties of Extracellular Pullulanase from Bacillus stearothermophllus G-82 M.S. Kambourova and E.I, Emanuilova... 

BIOSYNTHESIS AND PROPERTIES OF EXTRACELLULAR PULLULANASE FROM BACILLUS STEAROTHERMOPHILUS G-82... 

The production of thermostable enzymes, catalyzing reactions at high temperatures, is one of the most attractive features of thermophilic microorganisms. In order to select producers of thermostable hydrolases, different aerobic thermophilic bacterial strains were Isolated from water, soil and organic material samples collected from Bulgarian hot springs environment. Some of the properties of the Isolated strains were a subject of our previous work [1]. The aim of the present paper was to characterize and identify the strain producing thermostable pullulanase as well as to establish the optimum conditions for enzyme production and to study some of the enzyme s properties. 

A pullulanase in E. coli appears to be bound to the cell wall its properties are very similar to those of a pullulanase from Klebsiella (Aerobacter) aerogenes. However, no pullulanase activity was detected in cultures of E. coli grown on maltose. Neither this nor forty other strains of E. coli grew on pullulan, whereas all the strains grew on maltose, and some on maltotriose. The synthesis of pullulanase by various strains of Klebsiella (Aerobacter) aerogenes using maltose both as an inducer and as a source of carbon has been studied." Conditions leading to the synthesis of pullulanase were reported. 

A study of the metabolism of exogenous and endogenous carbohydrates by E. coli showed that pullulanase and other enzymes are induced by maltodextrins. The pullulanase, which appears to be bound to the cell wall, has properties similar to those of A. aerogenes pullulanase. It is suggested that E. coli uses pullulanase for debranching extracellular polysaccharides. 

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