Effect of Glucose Utilization on Nitrite Excretion by the Unicellular Cyanobacterium Synechocystis sp. Strain PCC 6803

Appl Environ Microbiol. 1993 Sep;59(9):3161-3. doi: 10.1128/aem.59.9.3161-3163.1993.

Abstract

Up to 1 mM nitrite was excreted by Synechocystis strain 6803 cells growing under mixotrophic or photoheterotrophic conditions. This excretion is not due to a lower ratio of nitrite and nitrate reductase activities in the presence of glucose but seems to be related to a shortage of reduced ferredoxin, their electron donor, as a result of a decrease in noncyclic photosynthetic flow observed under these circumstances. Because about 60% of the reduced nitrate is excreted, the potential utilization of cyanobacteria for removal of nitrate from contaminated waters containing high concentrations of organic compounds is questioned.