STABILITY OF SHORT AND LONG O-CHAIN LIPOPOLYSACCHARIDE TYPES IN RHIZOBIUM-GALEGAE AND THEIR CORRELATION WITH SYMBIOTIC PROPERTIES AND GROWTH-CONDITIONS, TOLERANCE OF LOW PH, ALUMINUM AND SALT IN THE GROWTH-MEDIUM

We recently showed that Rhizobium galegae strains had two different li popolysaccharide types, short and long O-chain. In the present study w e observed that the lipopolysaccharide type was a stable feature of th e strain. Both types persisted in cells at all phases of the growth cy cle, during differentiation of bacteria into bacteroids and when the c ells were grown under environmental stress. When R. galegae strains we re grown at low pH or in medium containing aluminum or sail, simulatin g conditions in acid soils of temperate regions and osmotic stress, re spectively, the tolerance of low pH was associated with the long O-cha in lipopolysaccharide and abundant acidic polysaccharide production.