Removal of nitrate from groundwater by cyanobacteria: quantitative assessment of factors influencing nitrate uptake
- PMID: 10618214
- PMCID: PMC91796
- DOI: 10.1128/AEM.66.1.133-139.2000
Removal of nitrate from groundwater by cyanobacteria: quantitative assessment of factors influencing nitrate uptake
Abstract
The feasibility of biologically removing nitrate from groundwater was tested by using cyanobacterial cultures in batch mode under laboratory conditions. Results demonstrated that nitrate-contaminated groundwater, when supplemented with phosphate and some trace elements, can be used as growth medium supporting vigorous growth of several strains of cyanobacteria. As cyanobacteria grew, nitrate was removed from the water. Of three species tested, Synechococcus sp. strain PCC 7942 displayed the highest nitrate uptake rate, but all species showed rapid removal of nitrate from groundwater. The nitrate uptake rate increased proportionally with increasing light intensity up to 100 micromol of photons m(-2) s(-1), which parallels photosynthetic activity. The nitrate uptake rate was affected by inoculum size (i.e., cell density), fixed-nitrogen level in the cells in the inoculum, and aeration rate, with vigorously aerated, nitrate-sufficient cells in mid-logarithmic phase having the highest long-term nitrate uptake rate. Average nitrate uptake rates up to 0.05 mM NO(3-) h(-1) could be achieved at a culture optical density at 730 nm of 0.5 to 1. 0 over a 2-day culture period. This result compares favorably with those reported for nitrate removal by other cyanobacteria and algae, and therefore effective nitrate removal from groundwater using this organism could be anticipated on large-scale operations.
Figures





References
-
- Ahlgren G. Phosphorus as growth-regulating factor relative to other environmental factors in cultured algae. Hydrobiologia. 1988;170:191–210.
-
- Boussiba S. Ammonia assimilation and its biotechnological aspects in cyanobacteria. In: Rai A K, editor. Cyanobacterial nitrogen metabolism and environmental biotechnology. New Delhi, India: Narosa Publishing House; 1997. pp. 35–72.
-
- Boussiba S, Richmond A. C-phycocyanin as a storage in the blue-green alga Spirulina platensis. Arch Microbiol. 1980;125:143–147.
Publication types
MeSH terms
Substances
LinkOut - more resources
Full Text Sources
Other Literature Sources
Research Materials