Distinctive light and CO/sub 2/-fixation requirements of nitrate and ammonium utilization by the cyanobacterium Anacystis nidulans

Journal Article · Sun Jun 01 04:00:00 EDT 1986 · Plant Physiol.; (United States)

OSTI ID:7188351

Lara, C; Romero, J M

The effect of light intensity on the rates of ammonium and nitrate uptake and of CO/sub 2/ fixation has been determined in intact Anacystis nidulans cells. Ammonium uptake became saturated at photon flux values of about 60 microeinsteins per square meter per second, whereas both nitrate uptake and CO/sub 2/ fixation reached saturation at about 250 microeinsteins per square meter per second, the rates of the two latter processes being tightly correlated at any light intensity assayed. Inhibition of ammonium assimilation resulted in the loss of correlation between CO/sub 2/ fixation and nitrate uptake, the latter process exhibiting then a reduced light requirement. The results establish a clear distinction between ammonium utilization and nitrate utilization with regard to their light requirement and to the nature of their dependence upon CO/sub 2/ fixation.

• Research Organization: CSIC, Sevilla, Spain
• OSTI ID: 7188351
• Journal Information: Plant Physiol.; (United States), Journal Name: Plant Physiol.; (United States) Vol. 81:2; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

550700* -- Microbiology
551000 -- Physiological Systems
59 BASIC BIOLOGICAL SCIENCES
AMMONIUM COMPOUNDS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON DIOXIDE FIXATION
CARBON OXIDES
CHALCOGENIDES
CYANOBACTERIA
ELECTROMAGNETIC RADIATION
MICROORGANISMS
NITRATES
NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
RADIATIONS
RESPONSE MODIFYING FACTORS
UPTAKE
VISIBLE RADIATION