Removal of nitrate from groundwater by cyanobacteria: Quantitative assessment of factors influencing nitrate uptake

Research output: Contribution to journalArticle

79 Scopus citations

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 μmol 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 NO3- 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.

Original languageEnglish (US)
Pages (from-to)133-139
Number of pages7
JournalApplied and environmental microbiology
Volume66
Issue number1
DOIs
StatePublished - Jan 2000

ASJC Scopus subject areas

  • Biotechnology
  • Food Science
  • Applied Microbiology and Biotechnology
  • Ecology

Fingerprint Dive into the research topics of 'Removal of nitrate from groundwater by cyanobacteria: Quantitative assessment of factors influencing nitrate uptake'. Together they form a unique fingerprint.

  • Cite this