Azotobacter nigricans nigricans Krasil'nikov 1949 (Approved Lists 1980) Azotobacter nigricans Krasil'nikov 1949 (Approved Lists 1980) Kennedy C. Rudnick P. MacDonald M.L. Melton T. Garrity G.M. Brenner D.J. Krieg N.R. Staley J.T. Genus III. Azotobacter Beijerinck 1901, 567AL 2005 2, Part B 2 384 402 Bergey's Manual of Systematic Bacteriology Springer New York 0387241442 Skerman V.B.D. McGowan V. Sneath P.H.A. Approved Lists of Bacterial Names 1980 30 1 225 420 International Journal of Systematic Bacteriology Int J Syst Bacteriol 0020-7713 10.1099/00207713-30-1-225