Heat-stable ureases from two filamentous cyanobacteria
Article Abstract:
Heat treatment and liquid chromatography help purify ureases of the cyanobacteria Anabaenal/Nostoc PCC 7120 and Leptolyngbya boryana to 1500-fold homogeneity, achieving very high specific activities. Three subunits of molecular masses 66 kDa, 14 kDa, and 18 kDa constitute the 220 kDa enzymes of both bacteria. Maximum activity of the Anabaena/Nostoc enzyme occurs at 8.5 pH and 65 degrees Celsius, while that of the Leptolyngbya enzyme occurs at pH 8.2 and 60 degrees Celsius. Both ureases are heat-stable and do not lose activity during incubation at 70 degrees Celsius for 15 min.
Publication Name: Microbiology
Subject: Biological sciences
ISSN: 1350-0872
Year: 1995
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Multiple oligomeric forms of glucose-6-phosphate dehydrogenase in cyanobacteria and the role of OpcA in the assembly process
Article Abstract:
A study was conducted to analyze the multiple molecular forms of glucose-6-phosphate dehydrogenase (G6PDH) in cyanobacteria. Cyanobacterial strains were prepared in BG11 and BG11(sub 0) media while cyanobacterial cultures were determined by centrifugation. Standard microbiological methods were utilized to isolate plasmids from Escherichia coli. Results showed that G6PDH from cyanobacteria supports multiple molecular forms associated with various aggregation states of the catalytic monomer.
Publication Name: Microbiology
Subject: Biological sciences
ISSN: 1350-0872
Year: 1998
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Nitrogenase quantity varies diurnally in a subset of cells within colonies of the non-heterocystous cyanobacteria Trichodesmium spp.
Article Abstract:
A study shows that the number of nitrogenase containing cells in naturally occurring species of the cyanobacteria Trichodesmium is higher during the day, when nitrogen fixation takes place, than in the evening. Also, the number of nitrogenase-containing cells is nearly constant during the day and decreases in the evening, falling to zero before dawn. The structure of these cells is not similar to that of heterocysts used by other bacteria to fix nitrogen.
Publication Name: Microbiology
Subject: Biological sciences
ISSN: 1350-0872
Year: 1995
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