1. A mild, reproducible extraction procedure, using 0.5% ammonium oxalate, was developed for the isolation of polysaccharides containing d-apiose from the cell wall of Lemna minor. On a dry-weight basis the polysaccharide fractions extracted with ammonium oxalate made up 14% of the material designated cell walls and contained 20% of the d-apiose originally present in the cell walls. The cell wa...

Pectin is an important structural component of the cell walls of all higher plants and is formed primarily during the early stages of cellular growth.1 The basic building unit of this polymer is known to be D-galactopyranosyluronic acid in which the linear skeleton of these units is connected by a-1,4-D-glycosidic linkages.2 The carboxyl groups of this compound are methylated to various degrees...

Pectin is a normal constituent of cell walls of green plants. When supplied externally to live cells or walls isolated from the large-celled green alga Chara corallina, pectin removes calcium from load-bearing cross-links in the wall, loosening the structure and allowing it to deform more rapidly under the action of turgor pressure. New Ca(2+) enters the vacated positions in the wall and the ex...

An earlier report (5) has described the effect of thiocyanate sprays on sugars and certain other constituents in apples. The present paper is a continuation of the general problem with attention directed to the pectic constituents. In previous work it was noted occasionally that apples spray.ed with thiocyanates were found to keep better in cold storage at 30 to 50 C. than control samples not s...

ETCHELLS, J. L., COSTILOW, R. N., AND BELL, T. A. 1952 Identification of yeasts from commercial cucumber fermentations in northern brining areas. Farlowia, 4, 249-264. JANSEN, E. F., AND MACDONNELL, L. R. 1945 Influence of methoxyl content of pectic substances on the action of polygalacturonase. Arch. Biochem., 8, 97-112. JANSEN, E. F., MACDONNELL, L. R., AND JANG, R. 1945 Simultaneous actions ...

Yeast polygalacturonase catalyzes a random hydrolysis of pectic acid to a mixture of digalacturonic and galacturonic acids via a series of oligogalacturonides (1). This enzyme will be termed yeast endo-polygalacturonase to differentiate it from end group-hydrolyzing enzymes, which have been named exopolygalacturonases (2). Evidence has been presented that yeast endo-polygalacturonase is a singl...

The isoelectric points of isolated cuticles from Citrus aurantium L. (3.15), Prunus armeniaca L. (3.45), and Pyrus communis L. (2.90) leaves were determined from membrane potentials. At pH values below the isoelectric point, cuticular membranes carry a net positive charge and are permselective to anions (determined using (82)Br(-)). Above the isoelectric point, they carry a net negative charge ...

Understanding the adsorption properties of polysaccharides in terms of substrate affinity, kinetics, and layer structure is of paramount importance in numerous industrial and natural systems. The structural growth of the layers of two model polysaccharides--sodium alginate and polygalacturonic acid (PGA)--was characterized by quartz crystal microbalance with dissipation and atomic force microsc...

Water contamination by heavy metals from industrial activities is a serious environmental concern. To mitigate heavy metal toxicity and to recover heavy metals for recycling, biomaterials used in phytoremediation and bio-sorbent filtration have recently drawn renewed attention. The filamentous protonemal cells of the moss Funaria hygrometrica can hyperaccumulate lead (Pb) up to 74% of their dry...