[Isolation and identification of N2-fixing strains of Bacillus in rice rhizosphere of the Yangtze River Valley].

Rice rhizosphere soil samples were colected from 10 sites of 7 provinces in the Yangzi River Valley, and from the soil samples 16 endospore-forming strains with ARA (Acetylene Reduction Activity) were isolated, the nitrogen fixing ability was tested by the method of 15N tracer and the atom 15N% excess are ranged from 0.0297% to 0.4714%. The strains were identified as Bacillus licheniformis, B. subtilis, B. azotoformans, B. cereus, B. pumilus, B. brevis, B. megaterium, B. firmu.