Biological dinitrogen fixation by selected soil cyanobacteria as affected by strain origin, morphotype, and light conditions

0349707 - BC 2011 RIV CZ eng J - Journal Article
Hrčková, K. - Šimek, Miloslav - Hrouzek, Pavel - Lukešová, Alena
Biological dinitrogen fixation by selected soil cyanobacteria as affected by strain origin, morphotype, and light conditions.
Folia Microbiologica. Roč. 55, č. 5 (2010), s. 467-473. ISSN 0015-5632. E-ISSN 1874-9356
R&D Projects: GA MŠMT LC06066; GA AV ČR IAA600660605
Institutional research plan: CEZ:AV0Z60660521; CEZ:AV0Z50200510
Keywords : biological dinitrogen fixation * soil cyanobacteria * strain origin
Subject RIV: EH - Ecology, Behaviour
Impact factor: 0.977, year: 2010

The potential for N₂ fixation by heterocystous cyanobacteria isolated from soils of different geographical areas was determined as nitrogenase activity (NA) using the acetylene reduction assay. Morphology of cyanobacteria had the largest influence on NA determined under light conditions. NA was generally higher in species lacking thick slime sheaths. The highest value (1446 nmol/h C₂H₄ per g fresh biomass) was found in the strain of branched cyanobacterium Hassalia (A Has 1) from the polar region. A quadratic relationship between NA and biomass was detected in the Tolypothrix group under light conditions. The decline of NA in dark relative to light conditions ranged from 37 to 100 % and differed among strains from distinct geographical areas. Unlike the NA of temperate and tropical strains, whose decline in dark relative to light was 24 and 17 %, respectively, the NA of polar strains declined to 1 % in the dark.
Permanent Link: http://hdl.handle.net/11104/0189869