Flavonoids influence growth and saccharide metabolism ofRhizobium meliloti

Abstract

Supplementation of the growth media with flavonoids,viz. naringenin, flavone, quercetin and syringaldehyde, a phenolic compound and alfalfa seed exudate, differently affected the growth and saccharide metabolism ofRhizobium meliloti. Quercetin increased while syringaldehyde, flavone and alfalfa exudate decreased the growth and protein content ofR. meliloti cells. Naringenin had no effect on growth and protein content though it increased the exopolysaccharide production. Application of naringenin increased the activities of enzymes of the citrate cycle and the 6-phosphogluconate pathway, the major pathways of sugar metabolism in fast growing rhizobia, and decreased activities of glycolytic enzymes. The activities of enzymes of the pentose phosphate pathway remained unaffected by various treatments.