Azospirillum brasilense Exopolysaccharide Complexes, their Possible Involvement in Bacteria-Wheat Roots Interactions and the Suggested Nature of these Interactions

Extracellular polysaccharides and polysaccharide-containing biopolymers from Azospirillum species: properties and the possible role in interaction with plant roots

“…At this point, there are no reliable data on the nature of LPPCs and PSLCs; therefore, their names should be taken as arbitrary [22,23,25]. Synthesis of the LPPCs and PSLCs by A. brasilense during growth in liquid medium is a common property of these bacteria.…”

“…A prominent feature of the PSs was that they had, though in small amounts, GlcN (1.1^5.6%). The exceptions were the PSs of the PSLCs from A. brasilense 15 and mutant strain Sp 7 (S-form), which contained only traces of GlcN and did not inhibit WGA activity in the reaction with erythrocytes [23,25]. The PSs of the PSLCs from Sp 7, Sp 107, Sp 245, Sp 246, S 17 and 75 inhibited WGA activity.…”

“…These PSs were separated using ion exchange chromatography. Further work was carried out using the quantitatively predominant acidic heteropolysaccharides [22,23,25,32]. The PSs gave transparent solutions in water, indicating that these solutions were true and that there occurred a loss of aggregation characteristic of LPPCs and PSLCs.…”

“…Like the living A. brasilense bacteria, the LPPCs and PSLCs from the strains studied are capable of increasing the numbers of deformations of wheat seedling root hairs [24,25].…”

“…Interaction of the PSLCs with WGA leads to increased numbers of wheat seedling root hair deformations [24,25]. With the goal of detecting the active portions of these complexes, their PS constituents have been isolated by chloroform treatment of aqueous solutions of the PSLCs from A. brasilense strains Sp 7, Sp 7 (S-form), Sp 245, S 17, 15 and 75 and of the modi¢ed PSLCs from Sp 107 and Sp 246.…”