Article Abstract:
Oxygenic phototrophs regulate the N2 fixation activated by anoxygenic phototrophs in microbial mat community in Bahamian hypersaline lagoon. Moderate reductions in the mat salinity fail to have any effect on photosynthesis, oxygen consumption or Na. Mat samples amended with 3-93,4-dichlorophenyl-1,1-dimethylurea show CO2 fixation, nearly 25% of that found in the nonamended samples. Amended samples also show photosynthetic activity regulated by anoxygenic phototrophs. Anoxygenic phototrophs is responsible for Na in amended samples also.
User Contributions:
Comment about this article or add new information about this topic:
Article Abstract:
The energy sources for nitrogen fixation in a marine microbial mat were determined and the nitrogen-fixing microorganisms within the mat were characterized. Experimental manipulation were performed to determine their effects on the normally high rates of nitrogen fixation at night. The results suggest that nitrogen fixation in these mats may be attributed to the activities of nonheterocystous cyanobacteria utilizing photosynthetically generated storage compounds under anoxic conditions at night.
User Contributions:
Comment about this article or add new information about this topic:
Article Abstract:
The characterization of cultivated Trichodesmium species was reported. A simple medium and handling procedures were used to maintain a nitrogen-fixing culture of Trichodesmium, isolated from Atlantic coastal waters, for over one year in the laboratory. The cultured population exhibits light-dependent nitrogen fixation during exponential growth. Various morphologies are present during growth. Moreover, cultivated aggregates exhibit spectral properties consistent with low-light adaptations.
User Contributions:
Comment about this article or add new information about this topic: