Effect of phosphate limitation on synthesis of periplasmic cyclic beta-(1,2)-glucans
Rhizobium meliloti and Agrobacterium tumefaciens synthesize periplasmic cyclic beta(1,2)-glucans during adaptation to hypoosmotic environments. It also appears that these glucans provide important functions during the interactions of these bacteria with plant hosts. A large fraction of these glucans...
Gespeichert in:
Veröffentlicht in: | Applied and environmental microbiology 1995-03, Vol.61 (3), p.1045-1053 |
---|---|
Hauptverfasser: | , , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | Rhizobium meliloti and Agrobacterium tumefaciens synthesize periplasmic cyclic beta(1,2)-glucans during adaptation to hypoosmotic environments. It also appears that these glucans provide important functions during the interactions of these bacteria with plant hosts. A large fraction of these glucans may become modified with anionic substituents such as phosphoglycerol or succinic acid; however, the role(s) of these substituents is unknown. In this study, we show that growth of these bacteria in phosphate-limited media leads to a dramatic reduction in the levels of phosphoglycerol substituents present on the periplasmic cyclic beta(1,2)-glucans. Under these growth conditions, R. meliloti 1021 was found to synthesize anionic cyclic beta-(1,2)-glucans containing only succinic acid substituents. Similar results were obtained with R. meliloti 7154 (an exoH mutant which lacks the ability to succinylate its high-molecular-weight exopolysaccharide), revealing that succinylation of the cyclic beta-(1,2)-glucans is mediated by an enzyme system distinct from that involved in the succinylation of exopolysaccharide. In contrast, when A. tumefaciens C58 was grown in a phosphate-limited medium, it was found to synthesize only neutral cyclic beta-(1,2)-glucans |
---|---|
ISSN: | 0099-2240 1098-5336 |
DOI: | 10.1128/AEM.61.3.1045-1053.1995 |