NEW STRAIN OF PARARHIZOBIUM SP. IB ST 1-4 ISOLATED FROM POOL FINGERS OF SHULGAN-TASH CAVE
From the mineral formation (pool fingers) of the shulgfan-Tash cave (Southern Urals) the first member of bacterial genus Pararhizobium was isolated (strain IB St 1-4). Pararhizobium is a genus of soil bacteria that fix nitrogen association with roots of legumes. Cells IB St 1-4 strain are Gram-negative straight rod-shaped bacterium (0,5-0,7×2,0-2,5μm). Growth is observed at 4-28°C with an optimum pH at 6-8. The strain precipitating of calcium carbonate on Ca-salts of malic acid in vitro. The relatedness of strain IB St 1-4 to members of Pararhizobium herbae, Pararhizobium giardinii and Pararhizobium polonicum species was revealed according physiological and biochemical features as well as phylogenetic analysis of the 16S rRNA gene sequence. The genes nifH and nodC that responsible for nitrogen fixation and plant nodulation in the strain IB St 1-4 were not detected.