scholarly journals Distribution of blue-green algae in soils of Chittagong University campus and their nitrogen fixing capacity

1970 ◽  
Vol 37 (1) ◽  
pp. 49-53
Author(s):  
MA Gafur ◽  
Soltana Parvin

Occurrence of blue-green algae in plain land, pond side, hilly area and dry rice field soils of Chittagong University Campus and N2 fixation of some of them have been studied. Twenty four species under 20 genera were identified and their number varied from 0.11×104/g to 2.8×104/g soil. Anabaena oryzae, Calothrix sp., Cylindrospermum majus and Hapalosiphon hibernicus and Nostoc spongiaeforme were selected for their nitrogen fixing potential. Maximum amount of total nitrogen was recorded in Nostoc spongiaeforme followed by Hapalosiphon hibernicus, Cylindrospermum majus, Anabaena oryzae and Calothrix sp. after 30 days growth in batch cultures.   Key words: BGA, Distribution, Nitrogen fixation doi:10.3329/bjb.v37i1.1563 Bangladesh J. Bot. 37(1): 49-53, 2008 (June)

The International Biological Programme served as a focal point for studies on biological nitrogen fixation during the 1960s. The introduction of the acetylene reduction technique for measuring nitrogenase activity in the field led to estimates becoming available of the contribution of lichens, blue-green algae, nodulated non-legumes and bacterial-grass associations, as well as of legumes. Other studies carried out on the physiology and biochemistry of the process led to the eventual purification and characterization of the nitrogenase enzyme. These studies, collectively, provided the springboard for current work, so essential in view of the present energy crisis, on how to increase the use and efficiency of nitrogen-fixing plants, on the metabolic regulation of the nitrogenase enzyme and on the genetics of the nitrogen-fixing process, both in higher plants and in free-living micro-organisms.


1942 ◽  
Vol 19 (1) ◽  
pp. 78-87
Author(s):  
G. E. FOGG

1. Anabaena cylindrica Lemin. has been obtained in pure unialgal bacteria-free culture. 2. Due precautions having been taken against contamination by other organisms and error due to absorption of fixed nitrogen from the atmosphere, this alga has been shown to possess the capacity of fixing nitrogen. 3. Nitrogen fixation does not take place in the presence of a sufficient quantity of readily available combined nitrogen.


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