Isolation from legume tissues of an agglutinin of saprophytic pseudomonads

Abstract

Water extracts from leaves, roots and stems of green bean and leaves of mung bean, soybean, and lima bean caused agglutination of cells of a saprophytic bacterium, Pseudomonas putida. The agglutinin from each source was purified in an identical manner using procedures of ion exchange, gel, and affinity chromatography. Purified preparations contained both carbohydrate and protein, were of high molecular weight (at least 106), required Mg2+ for activity and were heat stable. Less than 1 μg of hexose or protein of the purified preparations was required to completely agglutinate about 109P. putida cells. Arabinose, galactose and galacturonic acid were the predominant glycosyl residues detected in the purified agglutinin preparations. Agglutination tests with the crude and purified preparations from each legume showed strong and consistent agglutination with only pseudomonad saprophytes, P. putida, P. fluorescens, and P. aeruginosa. No agglutination of other plant pathogenic bacteria or nonpseudomonad saprophytes was observed.