Nitrogen fixation and nitrogenase activities in members of the family Rhodospirillaceae

Journal Article · Sun Jan 01 04:00:00 EST 1984 · J. Bacteriol.; (United States)

OSTI ID:6167371

Madigan, M; Cox, S S; Stegeman, R A

Strains of all 18 species of the family Rhodospirillaceae (nonsulfur photosynthetic bacteria) were studied for their comparative nitrogen-fixing abilities. All species, with the exception of Rhodocyclus purpureus, were capable of growth with N/sub 2/ as the sole nitrogen source under photosynthetic (anaerobic) conditions. Most rapid growth on N/sub 2/ was observed in strains of Rhodopseudomonas capsulata. Within the genus Rhodopseudomonas, the species R. capsulata, R. sphaeroides, R. viridis, R. gelatinosa, and R. blastica consistently showed the highest in vivo nitrogenase rates (with the acetylene reduction technique); nitrogenase rates in other species of Rhodopseudomonas and in most species of Rhodospirillum were notably lower. Chemotrophic (dark microaerobic) nitrogen fixation occurred in all species with the exception of one strain of Rhodospirillum fulvum; oxygen requirements for dark N/sub 2/ fixation varied considerably among species and even within strains of the same species. The authors conclude that the capacity to fix molecular nitrogen is virtually universal among members of the Rhodospirillaceae but that the efficacy of the process varies considerably among species.

• Research Organization: Southern Illinois Univ., Carbondale
• OSTI ID: 6167371
• Journal Information: J. Bacteriol.; (United States), Journal Name: J. Bacteriol.; (United States) Vol. 157:1; ISSN JOBAA
• Country of Publication: United States
• Language: English

Related Subjects

550700* -- Microbiology
59 BASIC BIOLOGICAL SCIENCES
ANAEROBIC CONDITIONS
BACTERIA
CHEMICAL REACTIONS
ENZYME ACTIVITY
GROWTH
MICROORGANISMS
NITROGEN FIXATION
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
RHODOPSEUDOMONAS
RHODOSPIRILLUM
SPECIES DIVERSITY
SYNTHESIS