FURTHER EVIDENCE THAT THE N-2-FIXING ENDOPHYTIC BACTERIUM FROM THE INTERCELLULAR SPACES OF SUGARCANE STEMS IS ACETOBACTER-DIAZOTROPHICUS

Nitrogen-fixing bacteria, isolated from the sugar solution in intercel lular spaces of sugarcane stems, were compared with the type strain of Acetobacter diazotrophicus (PAL-5) and found to be congruent with it in all characters studied. These characters were 37 morphological and biochemical tests, cellular fatty acid composition, and nitrogenase ac tivity. The nitrogenase activity was measured by acetylene reduction a nd H-2 evolution and found to be unusual in that the H-2 evolution was suppressed much less than expected by high concentrations of acetylen e.